This post started out as a comment that would have gone here (but would have done just as well here). But it became sufficiently long and possibly interesting that I figured it would make a good, if somewhat rough, blog post.

The presumption being examined here is that humans are divisible into different groups (races would be one term for those groups) that are genetically distinct from one another in a way that causes those groups to have group level differences in average intelligence, as measured by IQ. More exactly, this post is about the sequence of arguments that are usually made when people try to make this assertion.

The argument usually starts out noting that there are dozens of papers that document group differences in IQ. I’ll point out right now that most of those papers are published in journals with editorial boards staffed in part or in total with well known racist scientists such as J. Philippe Rushton. That fact is not too important to what I have to say here, but since the usual argument about race and IQ starts out with “Hey, look at all these papers in these great journals” it is worth noting.

Heritability of IQ measures is then proffered, often in reference to the famous “twin studies” which show a high heritability for IQ. Heritability is a measure derived from covariance between relatedness and some phenotype. Heritability is not genetic inheritance. It is scientifically incorrect and probably academically dishonest to assume or insist that a high heritability value means that something is genetic. It often is, but it need not be. The truth is, that there are many things that could have a high heritability value but that we know are not genetic, so we don’t make a heritability estimate. There are other things for which we have strong a priori biological arguments that hey are genetic, and we thus make heritability estimates as part of the research on those things. Then there are things that we don’t know the cause of, and in those cases, making an estimate of heritability is useful as an exploratory tool. But, and this is important, arriving at a high value for heritability does not indicate genetic inheritance.

If you apply the methodology of the twin studies to language, you would find that having the capacity of language is of a similar heritability of having one head (as opposed to zero or two heads, for instance): Undefined. The number of heads does not vary, and heritability is a measure of covariation (I use the term “covariation” in a non-technical sense here). If you apply these methodologies to what language someone speaks, the heritability for that trait is very high, much much higher than for IQ. If you apply the same method to heritability of geography (the lat/long of where someone lives), it is even higher, especially for babies or people living in traditional societies.

Does everyone understand why that is the case? Familial or cultural causes may be very strong but not genetic.

The smoke and mirror part of this is equating heritability with inheritance. We speak the language we speak because it is the language of the culture we grow up in, not because of a gene for speaking French vs. a gene for speaking Sumerian.

This makes sense because we know how a person acquires language, so no one even tries to measure heritability of which language someone speaks. (Same with heritability of geographic location. It would be an absurd measure.) But people make the assumption that intelligence is inherited. Why do they make that assumption? Because lots of people for a long time wanted to, and in some cases, needed to believe this so, and thus it has become part of our culture. It is part of our uncriticized received knowledge, along with other racialized ideas and various sexist ideas, and so on. But recent research (meaning over the last 30 years) has shown us that other than in the case if inherited neuro-developmental diseases, it is impossible to imagine how intelligence can be inherited in such a way as to explain the variability we see in the most inter-group differences. That there is some genetic component is not impossible, but it is very hard to maintain the idea that it is genetic and ethnic, or genetic and racial, or genetic and explanatory of more than a few IQ points in most people. There are no genes, there are no developmental mechanisms, that have been identified. So, to many the issue of inheritance (not heritability, but inheritance via genes) of intelligence is not really an issue.

However, there are many who still need to hang on to this belief. Why they need to hang on is itself an interesting question. I can’t say for a given individual but I’ve been engaged in this conversation for 30 years and in my experience it is very often because of a desire to support a racialized model of human behavior.

The evidence for the usual IQ/Group/Race/Ethnicity/Genetic model we see (and we are seeing it again now in the present discussion) is always given first as group differences. When the language and geography analogs are brought up, we always see the twin studies brought in. But twins are raised together in the same environment. So they have the same language, the same cultural customs, the same geography etc. That they have the same IQ is not surprising.

There is an interesting set of interactions between familial effects and environmental effects with any of these twin studies results, but it has to be understood that heritability is not inheritance. If you have a genetic mechanism that is real (not inferred or made up) that integrates with a developmental process that can manifest a phenotype based on a genotype (that is real, not made up or inferred) then you can translate heritability to genetic inheritance. We seem to see this in a number of psychological conditions/diseases, for instance, and obviously we see it for a lot of physical traits. If on the other and you have familial effects that would cause offspring to resemble their parents without genes then cultural/social/familial context is more likely to be the explanation.

Variation in IQ across groups in a single society (like in the US) (which is not the same as a single culture) is known to be primarily caused by SES and home environment, and is indicated by such things as parents’ educational level. Educational levels of Americans have been going up for a hundred years. So has IQ. IQ can jump up in a generation if one generation is educated and changes home environment and SES etc., and thereafter those offspring and grand offspring have higher IQ’s. No new alleles were introduced to cause those changes. Cultural differences were introduced, and we have a concept of the mechanism by how that works.

The next argument in favor of the genetic inheritance of intelligence is often to link IQ to head size or brain size. However, much of the data related to this research is very made up or cooked, the causal arrow is problematic. Also, a third or fourth level factor in IQ is diet, which may affect brain size. Separately, a primary factor in skull shape and bone thickness is also diet (though in totally unrelated ways) which in turn is ethnic/regional… Bottom line, the system is complex, but the data do not support the assertion unless you make a big part of the data up, and Rushton has famously done.

Another argument that is often made to salvage the genetic determination (by racial group) of intelligence is the between nation data that has been more recently assembled and foisted on us. This is no different than ethic groups in the US. IQ is a standard measure, and groups vary in this value. Other measures will also result in variation. The variation is there, and the group level distinction is there. But finding more examples of that does not lead towards the conclusion that this is racial or genetic.

The final argument in favor of the inheritance of IQ via genes passed on from parent to offspring is usually to cite the twins separated at birth studies. These studies, however, simply do not show this. These twins are not separated at birth in the way most people think they are Usually, the twins knew each other as they grew up, and/or knew commonly held family members. They lived in the same culture, usually in the same city, often in the same neighborhood, and sometimes even in the same physical house. Separated at birth in these studies usually means grandma and grandpa took one of the twins to raise because mom and dad were strapped. Grandma and grandpa may have lived down the street. The kids may have attended the same school, even the same classes, and spent a lot of time together outside of schooo.

I was separated (though not from birth) from my older brother, because he lived on the second floor of a two family house, and I lived on the first floor. By the exact criteria of the twin studies, we would be counted as separated. But, that household I grew up in was a single household that happened to be set up in a two family house. The two floors were connected by an internal rear stairway. I was rather shocked to realize at one point as a child that we were the only family with two kitchens. (Or two bathrooms, for that matter.)

There may be a small component of intelligence that is inherited, but it seems to be swamped by other factors. The insistence that genes determine intelligence and that these genes are divided up in our species by groups that are often defined racially is usually misguided, and seems scientifically wrong. The supra-ultimate argument, after the final argument, brought up in this sort of conversation is usually that the anti-racist argument is a Politically Correct argument, yada yada yada. But it is actually a scientific argument, and the racialized intelligence argument is not. Making the latter a politically incorrect argument. Which is kind of funny.

Comments

  1. #1 Colin Purrington
    December 22, 2009

    Too bad one can’t just do artificial selection for a few generations, just to see what type of realized heritability there would be. Probably wouldn’t get past ethics board…unless of course they were really, really dumb.

  2. #2 Scotlyn
    December 22, 2009

    I thought this debunking of “race” or “IQ” as useful constructs for understanding humans was already comprehensively taking place throughout the social sciences in my own college days in the late 70’s. I must have been very sheltered since, as, until I read the evil spewings of that white supremacist who found his way to your blog recently, I had not imagined that it would still be necessary to make this argument. Thanks for making it – and making it clearly. But I am so, so sorry that you have to!

  3. #3 MadScientist
    December 22, 2009

    There are also people who want to hang onto religion, and others want to hang onto those government aptitude tests (are they still around?). Gee, that was so long ago – I don’t know if I was meant to be a bum, a window washer, or president – maybe it was president of bum window washers. Once some bullshit is introduced to society at large, it’s hard to get rid of.

  4. #4 bryan pesta
    December 22, 2009

    Geez, that was long. I think I motivated this blog. First, I never claimed that group differences are genetic.

    I’ve met Rushton and interacted with him for at least an hour. We did not attend any white-pride rallies. Same with Jensen. I wonder if your opinion would change if you ever met/interacted with these people.

    I think it’s too conspiracy theorist to throw out all research published in the journal, Intelligence, because of the perception that some of its editors are racist.

    Rushton’s vita is on his university web site. If he gets his stuff past peer-review only because editors of his outlets are also racist, then this must by a vast conspiracy by scientists to get junk in motivated by racism versus scientific discovery.

    For example, Rushton alone has published in:
    The international journal of neuroscience,
    Biology Letters,
    Psychological Science, 17, 921-922 (arguably in the top 5 journals in all of social science)
    Psychology, Public Policy, and Law, 11, 235-294. (an APA journal, and therefore elite, and you’d be hard pressed to argue the APA is racist)
    Human Evolution,
    International Journal of Selection and Assessment,
    Psychonomic Bulletin and Review,
    Behavioral and Brain sciences.

    These are just from the first page of his vita. Claims that he gets stuff in because of a white-boy network are patently false, unless you’re willing to incriminate many people in many fields (including Science, for inviting Gottfredson to comment on IQ). Say what you will about Rushton, but I notice that most people who seek to discredit him have vitas that pale in comparison.

    In fact you are making very strong claims about integrity– to me almost slanderous. Another example is the brain size IQ link. There was a recent meta-analysis published on the link. I’ve co-authored with the person who did the meta analysis. He is a great scientist, and not racist. Claims otherwise demand evidence.

    My colleague here also has a meta-analysis published on race differences in job performance and how these vary by the cognitive demands of the job (published in an elite APA journal):

    MCKAY Patrick F. (1) ; MCDANIEL Michael A. (2) ;
    Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
    (1) University of Wisconsin-Milwaukee, ETATS-UNIS
    (2) Virginia Commonwealth University, ETATS-UNIS
    Résumé / Abstract
    This study is the largest meta-analysis to date of Black-White mean differences in work performance. The authors examined several moderators not addressed in previous research. Findings indicate that mean racial differences in performance favor Whites (d = 0.27). Effect sizes were most strongly moderated by criterion type and the cognitive loading of criteria, whereas data source and measurement level were influential moderators to a lesser extent. Greater mean differences were found for highly cognitively loaded criteria, data reported in unpublished sources, and for performance measures consisting of multiple item scales. On the basis of these findings, the authors hypothesize several potential determinants of mean racial differences in job performance.

    You could argue perhaps that my colleague (McDaniel) is racist, but probably not that McKay is, since he is an African American (with a really nice vita!)

    You’d probably have to argue that the armed forces are racist too, given how much weight they put on intelligence when selecting people into fields.

    More later, but you cannot win an argument by throwing out peer reviewed data by claiming editors are suspect, or racist. At least to do that, you’d need stronger evidence than “I disagree with the data”.

  5. #5 Katharine
    December 22, 2009

    Excellent post, Greg.

    FWIW, I’m going into this field, and it irks the fuck out of me that there are still people on both sides that think IQ is somehow a tool of racial engineering.

    A guy at the University of Chicago got death threats over this.

    I prefer to think of the study of intelligence and its interaction with the environment as a way to figure out what we can do to make a smarter society by improving the world.

    Intelligence is certainly heritable, but not to the extent that some would like. There is a clear pattern of smarter parents having smarter children, but one has to account for environmental influences such as parental behavior and resource availability. It doesn’t go to either extreme.

    Greg, I suggest you read some papers from people who are considered experts in this area: Paul Thompson, Robert Plomin, and Nick Martin. They discuss a genetic mechanism called quantitative trait loci which suggests that the genetic component of intelligence is somewhat graded in nature – the more mutations a person might have at a certain locus, the more intelligent a person is.

    Intelligence is neither barely heritable nor highly heritable; it’s somewhere in the middle.

  6. #6 Greg Laden
    December 22, 2009

    Katherine, I’ve read that literature. Variation in intelligence is highly heritable. It is only barely genetic.

  7. #7 Greg Laden
    December 22, 2009

    Bryan, why would you assume I’ve not interacted with my colleagues of thirty years?

    You only partly motivated the post. We just had a very unsatisfying discussion with a crazy guy which ws much more motivating, and I”m working on a related article.

    Bryan, I’m rather shocked and amazed that you have shifted so quickly to the very last bastion of the argument (as I defined in my post) rather than dealing with anything substantive.

  8. #8 Robert Bruce Thompson
    December 22, 2009

    You know, I always wonder about accusations of racism against Jensen and the rest, given that the consensus among those who argue that racial differences in IQ exist agree that the most gifted groups are those of Ashkenazi Jewish heritage (mean IQ ~ 115 on an SD15 scale) and the Chinese (mean IQ ~ 107). Given that white supremacists are unlikely to favor either of those groups, it seems disingenuous to accuse Jensen and his colleagues of racism.

  9. #9 bryan pesta
    December 22, 2009

    Don’t be shocked! It was my first reaction to a long post. I did mean “interact with jensen and rushton before deciding they were racist” (I’m assuming you’ve never met them).

    What bastion did I jump too; in looking back I don’t see it.

    As long as you’re interested, I’ll keep adding my 2 cents. Hopefully we will both learn something from the exchange.

  10. #10 Scotlyn
    December 22, 2009

    Bryan P, I can’t speak to the motivation for OP, but you are not the “white supremacist” referred to in my comment above, – I hate to speak of the divil, lest he appear – but that reference was to a commenter by name of “captainchaos”. You have yet to reveal what is behind your choice of preferred reading matter and tortured rhetoric. But Mr Chaos made his evil views fairly plain within a couple of jumps that started with a comment on climate change – oddly enough.

    I wonder though, how well any of us would fare on a test of our adaptive skills in, say, your average forest – where we could be surrounded by food, warmth and shelter, and have no clue how to access it, nor any idea which spider, vine, furry creature poses the greatest danger. I have no doubt that our shared cultural inheritance has so far distanced us from such knowledge, that we would get quite low FSQ’s (Forest Survival Quotients), compared to any, say, forest-dwelling group of people currently not scoring so well on an IQ tests. Like which language we learn to speak, I have no doubt that the set of things about which we “intellidge”? “intelligate”? – if I can be permitted to make a verb out of a noun – will depend greatly on a) how we were raised and b) what it may be most useful, given our culture and environment, to apply our intelligence to.

  11. #11 Scotlyn
    December 22, 2009

    Just one more thing. I do hesitate, as a layperson, to jump right into the IQ thing, but it seems reasonable to me that this is a measure of what a layperson like myself might call “bookish” intelligence – and therefore, I would hazard to predict that a higher acquaintance and familiarity with books generally would correlate with higher IQ scores. One thing that is shared by the cultural traditions associated with the Ashkenazi and Chinese heritage – cited here as having the highest IQ’s – is a verylong tradition of awarding high status to “bookish” performance. The Chinese have had the Imperial exams, which allowed a certain amount of upward mobility into the ranks of Chinese civil service based on examination performance, and the Ashkenazi have had the tradition of Talmudic scholarship, in which good “bookish” performance enhanced marriage prospects and status.

    The lower scores of groups that have been “bookishly” disadvantaged, both by poverty and other bars to education, as well as cultural traditions valuing skills other than bookish ones, would indicate to me just that – a lower tradition of bookishness, not carried in the genes.

  12. #12 Sinq
    December 22, 2009

    “the data do not support the assertion unless you make a big part of the data up, and Rushton has famously done.”

    What data did Rushton make up?

  13. #13 CDRealist
    December 22, 2009

    You seem to be saying that genetics is a very small component of intelligence, as well a saying that using this to infer differences among races or ethnic groups. Without imagining differences among groups, I thought it was clear that, within any group, some people are smarter than others, and this is partly genetic.

    Are you saying, as you seem to above, that in distinguishing between, say, Einstein and Sarah Palin, only a few of the 100 IQ points difference is due to genetics?

  14. #14 mk
    December 22, 2009

    @Katherine…

    Are you saying that if we took a baby from really smart parents and let it be raised by a poor family that for generations had lived in poverty with little access to any real education, that that baby would grow up smarter than the all the rest in that poor, uneducated family?

  15. #15 Greg Laden
    December 22, 2009

    Bob: I think the issue there is two fold. 1) The racialized IQ standard existed for 60 years or so as a to parter: Whites = 100 points, blacks = 85 points, Africans = 70 points, and the black IQ is the result of Africans getting fucked now and then by their white owners. Totally racialized, totally genetic. Then, 2) The adding in of a Asian morphology with five or six points more than the White IQ gave cover for the racialized anti-Black version.

    Which, by the way, you knew, and it’s kind of obnoxious that you ask like you’ve never heard this before, but whatever.

  16. #16 Greg Laden
    December 22, 2009

    Bryan, when you said “interact” I assumed you had meant “met”

  17. #17 bryan pesta
    December 22, 2009

    I see IQ as being more core / central / pure than the depth of knowledge one has acquired by exposure to culture and environment.

    It’s true, smart people know more, but that’s not what makes them smart, nor is knowledge IQ.

    I think it was the bell curve that made the argument: Why is Harvard (pick any elite school) world class? Because it makes people smart, or because the smartest go there. I know my answer to this question…

    Knowledge turns out to be a good indirect measure of IQ, through what can be called the back door:

    individual differences in brain efficiency (speed, capacity) = g/iq, which then causes people to differ in how much they learn (and how fastly they learn it) in any environment (and yes I’d guess that g predicts success even if the environment involves hunting with spears somewhere not West).

    It’s true that only an idiot would take an american vocabulary/IQ test into the jungles and make inferences about why the scores are so low.

    It would also be a waste of time to take tests that measure knowledge of white culture.

    No one does this.

    Instead researchers use something like the raven’s (no words on it; one must deduce, however, the pattern that comes next in a series of geometric patterns).

    That too is biased!

    Why then does it predict equally well for any subculture taking it (and statistically, why hasn’t anyone shown slope or intercept bias for minorities taking white IQ tests).

    My one contribution to the race/IQ literature was to show that race differences on an american / verbal based IQ test (The Wonderlic) were completely mediated by the race difference on elementary cognitive tasks.

    ECTs measure very basic information processing ability. I had two tasks. In one, 3 letters would appear on a computer screen (SAS), the subjects had to select as fast as possible, the position of the letter A (2nd position in this example). I coded how fast each person was on average and the variability around each person’s average from trial to trial.

    The second task was inspection time: 2 lines appear very briefly on a screen. You must decide– take as much time as you need– which line was longer, the left or the right.

    The measure here is how well you can maintain accuracy even when the lines are flashed very briefly (16 ms on some trials– two times faster than an eye blink).

    When controlling for performance on the ECTs, the race difference on the paper and pencil IQ test went away.

    Easy to explain (though the explanation may not be correct) if you believe that IQ is some basic index of how people differ in how fast and capable their brains process info.

    Nowhere in the article do I imply that the speed based difference is genetic. I think we just don’t know what’s causing it, but it’s there.

    Given how many institutions in America select based on IQ (colleges, the military, employers), I think it’s critically important to figure out what’s going on here. Or, we could hide our heads in the sand and pretend like IQ is invalid and that any classification based on skin color has to be racist and cannot provide any useful info about the plight of minorities in western societies.

    My apologies if it seems like I am ignoring specific comments from posters. Just trying to keep up / there’s lots of comments here.

  18. #18 SLC
    December 22, 2009

    I read someplace on the web that President Obama has an IQ of 142. I suppose that Mr. pesta would attribute that to his mother.

  19. #19 bryan pesta
    December 22, 2009

    Greg– real quick. Sorry then, you’re reply is a bit cryptic but it sounds like you have met them and come to some conclusions about their worlds views.

    I retract that statement then!

  20. #20 Stephanie Z
    December 22, 2009

    Why then does it predict equally well for any subculture taking it (and statistically, why hasn’t anyone shown slope or intercept bias for minorities taking white IQ tests).

    Predict what?

  21. #21 Bryan Pesta
    December 22, 2009

    You name it; educational performance; job performance; health rates; crime rates; income levels.

    The vast majority of the literature though is on education and job performance.

  22. #22 mk
    December 22, 2009

    @SLC…

    Damn! That means if she’d married a white dude he’d have an IQ of 284! Whoa. That guy’s wicked smart.

  23. #23 Greg Laden
    December 22, 2009

    Bryan, my understanding and thinkin on this issue goes back to my first reading about it, then working with Terry Deacon and some others, in the 1980s. My main research interests in include human evolution and human behavioral biology. Rushton has in the past been a regular attender (semi-regular, anyway) of the HBES and Physical Anthro meetings, as have I and I’ve met him at said meetings. But I don’t think meeting him has had anything to do one way or another with my thinking on this issue, which is based on reading and research.

    I’ve never met Jensen.

    I’m not sure how meeting/not meeting qualifies or disqualifies my professional opinion as a biological anthropologist, or affects my specific arguments.

  24. #24 Jason
    December 22, 2009

    I think one problem is that we’re talking about people, which inflames passions. It’s never upsetting when scientists say one strain of mouse may be more intelligent than another.

    If you believe that our thoughts and behaviors arise from the physical structure and physiological makeup of our brain, then you have to believe that the genetic program that creates our brain must play a significant role in determining how it operates, “intelligence” included. I do agree with the general tone, however, that factors like education/diet/social support can drown out genetic differences in behavior. Which is a good thing because it means there’s much that can be done to bring about equality of the different races of the world.

    I’m not rooting for any specific race in the intelligence debate, and I am not familiar with the human literature (and we could never do the experiment to actually determine the answer anyway) – it just seems highly likely to me that there are genetic differences that could be racially biased and that could contribute to intelligence. And so I think my main concern is that I never want to see passions get in the way of seeing possibilities. Now, reading back, I probably do agree with your main point is that genetic variability cannot explain the “variability we see in the most inter-group differences”…

    This is going to sound totally sappy but no matter how they’re inherited, each person, each race, has different qualities they bring forth. And these differences are valuable and can be celebrated, whether they have a genetic or an environmental basis. The one who doesn’t score so high on the type of intelligence measured by IQ tests is certainly intelligent in a way others are not. So is it such a big deal? Maybe I just argue this because I’m not sure I’d do too well on an IQ test myself ;)

  25. #25 bryan pesta
    December 22, 2009

    C’mon SLC, that’s a lame argument. There are literally 10s of millions of blacks in the USA alone smarter than 100s of millions of whites.

    I voted for barrack; found him inspiring (also found palin scary as hell).

    The smartest student I ever taught happened to be black.

    Group differences always have overlapping distributions. I doubt you could even find a regular racist here who would be foolish enough to think that IQ scholars believe all blacks score lower than all whites.

    It’s the same with height distributions by sex. Men on average are taller than women. We don’t to look hard to find a small guy and a tall girl. Does that invalidate the mean difference? Nope.

  26. #26 Greg Laden
    December 22, 2009

    I doubt Obama’s IQ is 142.

  27. #27 Greg Laden
    December 22, 2009

    The mean difference is real. The cause of the mean difference is in part the insistence that it is genetic with no evidence to suppor that.

  28. #28 bryan pesta
    December 22, 2009

    Gotta head out for a bit; my point re meeting Rushton wasn’t that you would then better admire and appreciate his science.

    The point was many– in my experience– characterize him as a rabid slobbering nazi. He is not, and least from the limited experience I had with him.

    So, I think discounting his work because he’s perceived as a racist is invalid (and even if he were a racist, the best way to discount a scientific argument is by evidence and reason, versus dismissing the source outright).

  29. #29 daedalus2u
    December 22, 2009

    Raven’s progressive matrices measure something which correlates with IQ measured with other tests in some populations, not in all. When different tests (Raven’s and Weschler) give answers that are as much as 70 percentile points different on the same individual, those different tests cannot be measuring the same thing no matter how well those tests correlate in other populations.

    http://www.ncbi.nlm.nih.gov/pubmed/17680932

    Exactly what they are measuring is not known. The absence of correlation proves they are not the same. Correlation in some populations may simply be artifact.

  30. #30 Greg Laden
    December 22, 2009

    If you believe that our thoughts and behaviors arise from the physical structure and physiological makeup of our brain, then you have to believe that the genetic program that creates our brain must play a significant role in determining how it operates, “intelligence” included.

    That is absolutely incorrect. Other than things going badly wrong with some brains due to a genetic factor, there is not one shred of evidence connecting the process of developing any of the brain function that we measure with intelligence tests with genetic variation. Quite the opposite. This statement can only be accepted as a very rough guess in the total absence of how human brains develop.

    it just seems highly likely to me that there are genetic differences that could be racially biased and that could contribute to intelligence

    Really? Why? This not be impossible, but it would be rather surprising.

    Jason, the arguments you are making here are typical of arguments made from, with all due respect, ignorance of all the important science one would need to address these questions. But your argument is in good accord with our fairly typical received wisdom of how humans work. Those who push racialized version of human intelligence have very little work to do in advancing their position because of this phenomenon. People are generally primed to accept this because culturally it seems so believable and real.

    Did you even read the post?

  31. #31 Dr Brainz
    December 22, 2009

    Greg: You need to connect the dots. “Jason” is a friend of “Bryan” apparently.

  32. #32 mk
    December 22, 2009

    It’s the same with height distributions by sex. Men on average are taller than women. We don’t to look hard to find a small guy and a tall girl. Does that invalidate the mean difference? Nope.

    So on average whites are smarter than blacks?

  33. #33 Stephanie Z
    December 22, 2009

    Nowhere in the article do I imply that the speed based difference is genetic. I think we just don’t know what’s causing it, but it’s there.

    As I mentioned in the comments at Quiche Moraine, this isn’t science. This is throwing one’s hands up and saying, “Don’t look at me. I just got the results I got. I’m not going to try to fit my work into the literature of make any further hypotheses from here.”

    There are plenty of factors well known to correlate with racial categorization, IQ and those outcomes that correlate with IQ (which is not “name it”). The fact that there is a set of race-IQ literature that says, “I’m not saying it’s genetic,” without discussing these other factors and their cumulative effect is, at the least, short-sighted.

  34. #34 Sven DiMilo
    December 22, 2009

    there is not one shred of evidence connecting the process of developing any of the brain function that we measure with intelligence tests with genetic variation.

    Wasn’t there a recent study that correlated genetically based variation in myelin thickness with some measure of intelligence? I guess I’m remembering this.

    I am far, far from immersed in this literature, but on the face of it I find the suggestion that genes do not influence variation in intelligence (leaving aside the difficulty in defining or measuring what that means) bizarre.
    Why would brain development and function be different from every other phenotypic character?

  35. #35 Colugo
    December 22, 2009

    I have a PhD in anthropology and am a former member of HBES. I’m not that young. I’ve seen the last of wave this (Rushton and comrades) and now it’s clear that we are seeing a troubling new wave of racialist science (HBD, whatever). It is distinct from earlier waves in that:

    1) Its ‘sexiest’ tool is molecular genetic assays rather than evolutionary ecology theory-building, pencil and paper IQ tests, or heritability studies of earlier waves.
    2) Its advocates include anthropologists and bona fide biologists rather than just psychometrists and and behavioral geneticists.
    3) Its advocates even include political liberals.
    4) There is an associated subculture of bloggers who appear to be young and educated.
    5) Some prominent academics are coming out of the HBD closet, some of them coyly, some boldly. Their books are being used as required reading for grad students.
    6) They are being given platforms, either directly or in friendly reviews, in publications like The Economist, Psychology Today, Edge, and Seed.

    http://www.economist.com/displaystory.cfm?story_id=14742737

    http://www.edge.org/q2009/q09_4.html#haidt

  36. #36 Greg Laden
    December 22, 2009

    Sven, yes, I’m familiar with this. What does it have to do with the question of genetic determination of intelligence? Are you thinking that myelin is some sort of gene? It isn’t!

    Brain development is quite different from most other characters. the question “why don’t we assume that brain development is the same as any other character” is right on the bingo card, by the way.

  37. #37 Jon M.
    December 22, 2009

    I think this is a great essay, and you’ve done a great job outlining the usual arguments, how they work, and why they are meaningless. To this you can add as textbook examples of the white supremacist pseudo-science several paragraphs from some of these comments that appeal to “common sense” but spout common nonsense.

  38. #38 Elfie
    December 22, 2009

    @Colugo: So what’s the big deal about that Economist article? I’m outside the field, educate me – all I see is that they’re collecting gobs of DNA data.

  39. #39 Neurodoc
    December 22, 2009

    Neural development in mammalian cortex is not genetically determined at anything close to a fine scale. There are tens of billions of connections which can not be specified at any level of detail, which might have influenced intelligence, coded for by thousands of genes. It is impossible for variation in alleles to have much to do with variation in intelligence as it might be measured by something like IQ or, really, any other measure. The genes are like a zoning commission for a city with little foreordained effect on what will ultimately happen when the city is filled out with streets and homes.

    This lack of genetic coding for cortical neural structures is well established in neurobiology but usually summarily ignored by pundits who wish to link population norms to race categories. But you can not ignore the physiology, or at least, should not.

  40. #40 Sinq
    December 22, 2009

    What data did Rushton make up?

  41. #41 Anon
    December 22, 2009

    The idea that genetics plays no part in intelligence is insane. Or are you going to tell me that, given the same upbringing, the earthworms in his garden would be every bit as intelligent as any human? Because after all, the only significant difference between their species and our species is one of genetics.

  42. #42 Stephanie Z
    December 22, 2009

    Anon @41, read comment 39.

  43. #43 Jim Thomerson
    December 22, 2009

    Given my IQ (none of your business), I suspect Obama is 142 or better.

  44. #44 Greg Laden
    December 22, 2009

    Anon, the conversation is not about differences between organisms with brains and those without, but rather, about variation across individuals of the same species.

    I can see where you would make this error. Most people who are utterly ignorant of biology easily fool themselves (or are fooled by others who want them to think a certain way) into conflating intraspecies and interspecies differences.

    Let me ask you as question that might help orient your neurons on this one: What would comparing earthworms, who have no langauge, with humans, who have language, tell us about how language works in humans?

  45. #45 Greg Laden
    December 22, 2009

    I suspect Obama is 142 or better.

    My thoughts exactly.

    By the way, my comment that I doubted Obama’s IQ is 142 was really really funny but no one got it. I guess it went over everyone’s head.

    Obama would have gotten it.

  46. #46 Colugo
    December 22, 2009

    Sinq, how about this from The Economist:

    “The few who really understand the genetics will gain a more enlightened, live-and-let-live recognition of the biodiversity within our extraordinary species—including a clearer view of likely comparative advantages between the world’s different economies.”

    Or this from The Edge.org piece:

    “I believe that the “Bell Curve” wars of the 1990s, over race differences in intelligence, will seem genteel and short-lived compared to the coming arguments over ethnic differences in moralized traits. I predict that this “war” will break out between 2012 and 2017.”

    This is similar to the BS thesis of the 10K Explosion – namely, that genetic differences between human populations explains social differences over time and place: history, economics, culture etc. Racial differences in intelligence is only part of the picture.

    It’s junk science based on empirically flimsy handwaving.

    There is a guy named Jason Richwine, a protégé of Charles Murray at conservative American Enterprise Institute, spewing the same kind of bull. For example, Richwine claims that genetic differences between various white ethnic groups are responsible for group differences in civic participation.

  47. #47 Irene
    December 22, 2009

    I think being Republican has been shown to be genetic. So that fits with the OP’s thesis, as this would be a psychological disease of some sort.

  48. #48 Bryan
    December 22, 2009

    #29Raven’s progressive matrices measure something which correlates with IQ measured with other tests in some populations, not in all. When different tests (Raven’s and Weschler) give answers that are as much as 70 percentile points different on the same individual, those different tests cannot be measuring the same thing no matter how well those tests correlate in other populations.

    I disagree completely and think the data back me up (e.g., the law of positive manifold).

    Your cite is a study on autistic children. I’d stipulate that traditional IQ tests are not good for people with developmental disabilities (they’re made to assess so called “normal” people). You can’t criticize a test for failing to diagnose something it was never intended to measure.

    I do agree that’s it’s tough to compare IQs from one test taken by this group over there to IQs from another test taken from that group over here.

    The problem is any one IQ test is more or less a measure of g. A 108 on the wonderlic might not translate to a 108 on the ravens or the wais.

    I don’t think this problem is as bad as it sounds.
    Where I think IQ tests have real value is: 1) ranking people who all take the same test at the same time in the same conditions, or (2) aggregating scores and making decisions based on them over time (as a company might do when deciding to hire the next 1000 applicants; or a school might do when deciding who to admit).

    If I knew a single person’s IQ, I couldn’t do much prediction wise with any great confidence (unless it were an extreme score). I could make some better than chance inferences, but the error rates would probably be large.

    So, with n=1, unless the score is extreme, only weak probabilistic statements can be made. When data are aggregated, it’s not uncommon to see IQ correlate near perfectly with other aggregate variables.

  49. #49 Sven DiMilo
    December 22, 2009

    Do I think myelin is a gene?
    Naw, I teach physiology for a living and I know what freakin myelin is. Here‘s the abstract of the article. It sez:

    In a cross-trait mapping approach, common genetic factors mediated the correlation between IQ and white matter integrity, suggesting a common physiological mechanism for both, and common genetic determination.

    and that’s all I know about it, besides the quotes in the press release linked earlier. But I think you have to admit that it seems to have something to do with the question of genetic determination of intelligence,

    There are tens of billions of connections which can not be specified at any level of detail, which might have influenced intelligence, coded for by thousands of genes.

    I can’t figure out what that means. Is your point the vastly larger number of synapses than genes? So much for the ‘one synapse/one gene’ hypothesis. But since you guys (I am assuming you are a neuroscientist of some sort?) don’t know how the brain works in any detail at all–and how could you?–it seems premature to profess such certainty about how genes (might) work–as they must, I think, no?–to set up the common neurological framework of Homo sapiens. And then, what do we know about the variation, subtle and not-so, possible on top of that? Bupkis? What do you know that I do not?

    There are tens of billions of connections which can not be specified at any level of detail, which might have influenced intelligence, coded for by thousands of genes. It is impossible for variation in alleles to have much to do with variation in intelligence as it might be measured by something like IQ or, really, any other measure. The genes are like a zoning commission for a city with little foreordained effect on what will ultimately happen when the city is filled out with streets and homes.

    I find the confidence with which you make such assertions surprising and, frankly, dubious. For some reason I am ignorant of the science that would support your claims…can you point me in the right direction?

    This lack of genetic coding for cortical neural structures is well established in neurobiology

    Sorry to be a picky dick, but when you say “structures,” what do you mean exactly?

    but usually summarily ignored by pundits who wish to link population norms to race categories.

    I can assure you that that is not my wish, and nor am I a pundit. I ignore this putative lack because I don’t know about it. Link?

  50. #50 Stephanie Z
    December 22, 2009

    Congratulations, Bryan. “Law of positive manifold” is a Google whack; i.e., not much of a law.

  51. #51 Jason Thibeault
    December 22, 2009

    Stephanie @50: technically it’s only a Googlewhack if it’s exactly two words. </pedant>

  52. #52 Stephanie Z
    December 22, 2009

    Jason, that was kind of part of the point re: authoritative-sounding jargon. It was subtle, though.

  53. #53 Bryan
    December 22, 2009

    I don’t know Jason, nor would I make a sock puppet to argue my point. I hope that’s clear (I’m using my real / full name here afterall). At the end of the day, no one’s going to change their mind by our discussion (thus is human nature), but I still think it’s worth having.

  54. #54 Jason Thibeault
    December 22, 2009

    Don’t worry Bryan, they know I’m not you, nor am I defending you. By any stretch of the imagination.

  55. #55 Greg Laden
    December 22, 2009

    Sven, as I said above, there is evidence for genetic variation in intelligence. That variation, though, has two characteristics. 1) It is not much variation, and 2) it is not correlated with the racial groupings that are otherwise touted as determinative.

    We know a fair amount about how neural circuitry develops in an individual, and you can probably learn about it too if you want to skip the sophistic arguments. I get the impression you are not interested. The short version is that the kinds of differences in brains that would likely relate to differences in intelligence develop the way they do conditionally, not because of genetic coding. Please also refer back to the basic idea that when we look for non genetic explanations for the large and disturbing group mean differences that we do see find them. They are really obvious.

    The genetic component is not important.

  56. #56 Jason Thibeault
    December 22, 2009

    Oh. Another Jason is in this thread. That’s what I get for skimming to the juicy fighty bits.

  57. #57 Bryan
    December 22, 2009

    “So on average whites are smarter than blacks? ”

    There is a group mean difference favoring whites on IQ tests. The difference has been replicated since WWI (army alpha). The difference also shows up an so called achievement tests (SAT, GRE, LSAT, etc.) and on the army ASVAB.

    The above is undeniable. It’s just the data. Where racism may come in is the explanation for the data. That can range from the scores are dry-lab’ed junk science motivated by racism, to the scores represent genetic differences among the races. If you believe IQ tests measure smarts, then the conclusion follows, but applies to the two groups versus any individuals in the groups.

    I still point out that I’ve never claimed the differences are genetic. I honestly don’t know, but I think simple explanations (i.e., SES, test bias) have been ruled out ad naseum. I also don’t claim expertise in genetics, nor do I necessarily want to study it / become an expert just to have a stronger / more educated opinion on race differences (I started replying here by saying let’s hold off discussing race and IQ but it quickly turned to that).

  58. #58 Greg Laden
    December 22, 2009

    I am not trying changing people’s mind. Rather, I’m in the business of helping people to become more educated in certain areas. I promise you that I receive enough notes that say something like “Man, I totally didn’t get that … but now I do. Thanks for helping me being a scientific racist” (or the equivalent in other areas) to keep me quite satisfied.

  59. #59 Bryan
    December 22, 2009

    Stephanie. I really think my one study in the area cannot speak to the cause of the difference. It was never intended to do that. It shows that paper and pencil differences are explained by information processing ability, but not why.

    No single study is obligated to answer all questions that might arise, especially those it was never designed to address.

    So, I really don’t know why races differ on average in cognitive speed. I suspect it could be nutrition, prenatal development or something else– possibly genetics, but I don’t know.

  60. #60 Anon
    December 22, 2009

    Here’s a question for you Greg. If intelligence isn’t genetic, then how did humans evolve brains capable of greater intelligence than any other creature? After all, the only difference between a chimpanzee and a human is after all the genetic structure that builds the creature. That the current research isn’t able to find the causes of the measurable difference in intelligence between species doesn’t mean that it’s not genetic. If you can’t find the genetic causes behind brain structures, then you shouldn’t go about proclaiming that they don’t exist, because if genes don’t determine brain development, what does? And if your answer wouldn’t produce a chimpanzee, or dog, or cat of similar intelligence to a human, then your answer is wrong.

  61. #61 Greg Laden
    December 22, 2009

    Bryan. SES ruled out? Seriously?

    If you wish to cite the full range of “IQ” data from WWI to the present at “the data that speaks for itself” then you also have rule out a great deal of it for a wide range of reasons. Are you familiar with the early IQ tests? Clearly not. Taking the panoply of IQ tests and test circumstances, bias, SES, nefarious strategy (as in the calculation of the famous “African 70″ by apartheid era South African scientits) and so on are all factors explaining a lot of that data.

    There is a remaining difference in properly administered IQ tests. Bias is NOT eliminated. SES is still a factor. Home environment is still a factor. It is simply not the case that everything but genetics has been ruled out as you seem to imply.

    I am starting to find it hard to believe that you don’t hold any strong opinion on the role of race.

    My bing card. It is starting to get full. And my patience is starting to get short.

    Next step: Bring on the ad hominem invectives. Nothing else left, really.

  62. #62 Bryan
    December 22, 2009

    Lots of people seem to smugly dismiss all this (at least in my opinion) without saying why.

    Why is it junk science?

    Some examples in the peer reviewed / decent journal literature???

    I linked to my study somewhere. Feel free to critique it and tell me why it sucks.

  63. #63 Greg Laden
    December 22, 2009

    Anon, that’s a good question and there is a very interesting set of answers to that question. But you are unprepared for this discussion in my judgement. And, I’m moving on to other things and I’ve had a long day. I write about that topic now and then. Just read and try to actually understand my answer to your previous question.

  64. #64 Bryan
    December 22, 2009

    I don’t know what a google whack is but the positive manifold has been called a “law” for decades in the literature and is standard terminology in the field. How can I be criticized for using standard terminology (perceptual psychology has a few “laws” too, though we realize we’re all doing junk science in psych, it makes us feel better to write “law”)?

    Find a data set that doesn’t show the PM, then you’d be onto something.

    Google whacked?!

  65. #65 Stephanie Z
    December 22, 2009

    Bryan, you can Google it.

  66. #66 Sven DiMilo
    December 22, 2009

    you can probably learn about it too if you want to skip the sophistic arguments. I get the impression you are not interested.

    Ah.
    And then followed by unreferenced assertions about what genes can and can’t do in brain development.
    So this is your idea of “helping people to become more educated in certain areas”?

    But anyway. I’ve not even been talking about differences among groups (though yes I realize it’s the topic of the OP and so I spose I’m OT as well as “sophistic”). OK? I am only addressing the specific argument that any observed differences among groups in any putative measure of intelligence cannot possibly be genetically based because it is physiologically impossible for allelic variation to influence intelligence. And, really, the weird certainty with which that argument is made.
    Seems unwarranted, and though I have explicitly asked for pointers to more information, instead I got the snidely asserted short version and a brushoff based on an “impression.” *shrug*

  67. #67 Bryan
    December 22, 2009

    Gesh Greg, I think I’ve been pretty patient here. I haven’t seen any specific arguments just a lot of general comments and some smugness (not necc on your part).

    There’s a section in the neisser article (APA task force) that says something like: it’s clear that no explanation for race differences that appeals to simple SES will do. I think a very fair summary of the massive literature on this topic is that controlling for SES does not eliminate the difference (an oft cited finding is that the IQ difference between poor whites and blacks is much smaller than the iq difference between rich whites and blacks).

    I agree the early IQ tests sucked compared with today’s. Why does that surprise you?

    Have you seen my lob any ad homs? I’m trying to be– and think I have been– a complete gentlemen.

    I do have a strong opinion on race differences on IQ tests– they exist and have important consequences and cannot be explained away by the obvious things everyone always brings up (test bias; SES differences, etc). Even scholars on the other side have abandoned these explanations for ones that focus on culture versus environment.

    Getting tired; gonna take a break for now.

    Fortunately, I am off til mid January, so I will reply for as long as you guys can stand me. And, please do point out where you think I am being rude or non-responsive (it is a burden though trying to respond to every post made by every person).

    B

  68. #68 Anon
    December 22, 2009

    I did read your previous answer. It was precisely the nonsense that I expected you to post. And thanks for admitting that you feel that you are an authority on the subject, and that therefore your opinion does not need to be defended. It lets me know not to bother reading anything you write.

    The only difference between species is the genetic code that controls development. The argument that genetics plays no part in intelligence is nothing more than lingering religious wanking about consciousness and the soul.

  69. #69 Greg Laden
    December 22, 2009

    Sven. You are making a positive statement. You are making the claim that there is a genetic system that determines intelligence, that there is variation in the genetic system that determines variation in intelligence, and that this variation is partitioned by race.

    Prove it. Don’t tell me that I am not effectively countermanding your point. You have produced nothing to countermand. Nothing said by any of the race-model supporters on this thread has included actual evidence (other than “it must be” and “its gotta be” and so on) and nothing said has even addressed, let alone effectively criticized the contents of the post (remember the post? look up at the top of the page and you’ll see it).

    The truth is that this is a complex issue, and a very interseting one. Like climate change. That’s also complex and interseting. I love talking about both topics with sincere individuals who know something about it. I also enjoy arguing with denialists or racist trolls. But there are limits to how interesting that is.

    Repeatedly avoiding the argument then demanding that the argument be addressed is unacceptable. But it is also exactly what I expected, and it is really, really offensive and boring.

  70. #70 Blake Stacey
    December 22, 2009

    “The argument that genetics plays no part in intelligence is nothing more than lingering religious wanking about consciousness and the soul.”

    Ooh! Ooh! A strawman, glimpsed in its natural habitat! How exciting!

    (Evolutionary-psychology fanboys pull a similar ploy pretty often: “You’re claiming that the human brain is exempt from evolution, you ignorant mystic!” No, human brains are not “exempt from evolution”, but neither are you exempt from the standards of scientific evidence.)

  71. #71 Sinq
    December 22, 2009

    What data did Rushton make up? E.O. Wilson once described Rushton as “An honest and capable researcher.” Hans Eysenck said “Professor Rushton is widely known and respected for the unusual combination of rigour and originality in his work.” Comparing their backgrounds to yours, it’s rational to give far greater weight to the opinions of Wilson and Eysenck than yours.

  72. #72 Greg Laden
    December 22, 2009

    Sking, you are on thin ice here. I’ve red the back of the book too.

    Have you read the inside? I actualy have a one hour lecture I use as a methods example in which I take apart Rushton’s argument in detail. Some day I’ll write it up for the blog. It is way beyond what can go in a comment.

    Let’s just say that it has to do with skull thickness and brain size in Africans.

    I never heard Ed Wilson say anything bad about anybody, in person, BTW.

  73. #73 Stephanie Z
    December 22, 2009

    Sinq, if you can find defenses of Rushton, it’s also quite easy to find the criticisms. Why are you asking Greg to do the work for you?

  74. #74 Sinq
    December 22, 2009

    “Prove it. Don’t tell me that I am not effectively countermanding your point. You have produced nothing to countermand. Nothing said by any of the race-model supporters on this thread has included actual evidence ”

    Jensen and Rushton publich in peer reviewed journals. You say they are wrong, but haven’t provided any equivalent evidence for that, or for your other contentions.

  75. #75 Jason Thibeault
    December 22, 2009

    I’m trying to be– and think I have been– a complete gentlemen.

    Bryan: You failed at it over at Quiche Moraine when you opted to call Stephanie “Steph” then underscored the diminutive by apologizing and reverting to calling Greg “Gregory”, when neither had used their names as such. That’s not terribly cordial to the people involved in this conversation, regardless of the content of your message, and that’s as much part of this discussion as this thread, I have to note.

  76. #76 Sinq
    December 22, 2009

    Laden, so you are saying Rushton faked skull and brain size data? What specific publications of his use the faked data?

  77. #77 Greg Laden
    December 22, 2009

    Well, they publish in journals that they are editors of, and can’t get their stuff published in most other journals most of the time. This is well known and a general embarrassment in academia.

    But, if you like, you can certainly cite them. Where exactly do they demonstrate your point?

  78. #78 Greg Laden
    December 22, 2009

    Sinq, I imagine you turning red and stomping your feet.

  79. #79 Stephanie Z
    December 22, 2009

    Sinq, Greg provided a link to a whole post of readings in IQ and Intelligence (second link in the post). It’s hardly his fault if you don’t go read. Stop asking him to hold your hand.

  80. #80 Sing
    December 22, 2009

    Stephanie, I’m not asking Laden to do anything other than support his claim Rushton faked data.

  81. #81 Stephanie Z
    December 22, 2009

    I’m not asking Laden to do anything other than support his claim Rushton faked data.

    You say they are wrong, but haven’t provided any equivalent evidence for that, or for your other contentions.

  82. #82 Greg Laden
    December 22, 2009

    Perhaps “faked” is too strong a word. perhaps “made up” is more appropriate.

    By the way, I think “anon” may be JPR himself. They make the same exact mistake in logic regarding intraspecific vs. specific.

    OK, I’ll give you one of several instances., Rushton, in his famous book, estimates “black, white, and asian” brain sizes by getting (questionable) data from the outside of the skull (circumference) and using that to estimate brain size by subtacting skull thickness and then using a formula.

    But, in so doing, he subtracts a larger amount for the “african” skulls than for the other skulls. The reason he does this is because, he claims, that African skulls are thicker. Despite the fact that we have a lot of data on this, and many groups of Africans have thinner skulls than Europeans, he picks one skull from Africa, which is not a modern human, and uses that neanderthal-like skull to represent the entire fucking continent.

    By having this very thick African skull to subtract, he gets the African brains to become smaller in his calculation than they otherwise would.

    I predict this will not satisfy you, but it is true. What a nice guy.

  83. #83 Elizabeth
    December 22, 2009

    As I recall from a class I once attended the data for the outside of the head was also questionable. Most of it came from measurements taken for hat size for soldiers entering the army.

  84. #84 Thomas
    December 22, 2009

    I can not believe that people still think this. As the white father of an adopted African child, who for good reasons know six other children like mine, I promise you that either the claimed low IQ of Africans is a sham, or the genetic causality is bogus. I understand that this is anecdotal, but not entirely devoid of meaning.

  85. #85 Jason Thibeault
    December 22, 2009

    After seeing so often and for so long that Rushton repeatedly assumes that intelligence differentials are mostly genetic, and his methodologies presuppose that “fact”, perhaps it’s time to consider that Rushton is under the thrall of the wrong “First Law of Intelligence”. e.g. Michael Shermer’s.

    “Smart people are very good at rationalising things they came to believe for unsmart reasons.”

  86. #86 Paul
    December 22, 2009

    Huh.

    As soon as the magnitude of Rushton’s data cooking is exposed the rats seem to have jumped off the ship. All is quiet on the white boy front.

  87. #87 Sinq
    December 22, 2009

    “he picks one skull from Africa, which is not a modern human”

    He averaged multiple published datasets, so it’s strange you have that notion. Given your biases it’s hard to tell if it’s an honest mistake on your part.

  88. #88 Greg Laden
    December 22, 2009

    You are not looking in the right place. This is a bit hard to find but it is there. A correction to the data are made based on an overestimate of African skull thickness provided by reference to this fossil skull.

    You might have to look in a previously published paper to find it, I can’t remember.

    Now, when you said

    Given your biases it’s hard to tell if it’s an honest mistake on your part.

    did you hear that thin ice cracking? Do you detect the irony? You’ve got it wrong and you’re telling me that since you are not seeing this that I may be being dishonest. Crack crack crack .

  89. #89 Jason Thibeault
    December 22, 2009

    Sinq: I suspect the fact that Ugandans have larger brains than Europeans yet have an IQ of 73 ( http://hypnosis.home.netcom.com/iq_vs_religiosity.htm ), while Vietnamese have the smallest brains on the planet and an IQ of 96, disproves basically everything Rushton had to say on the topic of brain size predicting IQ with any strong positive correlation. Regardless of Rushton’s methodologies (and I have no reason to doubt Greg’s analysis), the theory does not match all available evidence and is therefore exemplar of cherrypicking to rationalize his already-held belief.

  90. #90 Greg Laden
    December 22, 2009

    Jason, I did not mention above, but Rushton also uses a bogus adjustment to thin-out asian skulls and thus get them bigger brains. SO YOU ARE RONG!!!!

  91. #91 Sinq
    December 22, 2009

    “I can’t remember.”

    Of course not.

    “You’ve got it wrong”

    You keep insisting everyone is wrong, including scientists with far more expertise and publications than you. Unfortunately being insistent doesn’t prove anything.

  92. #92 vonagan cheeseman
    December 22, 2009

    I have read in a highly regarded journal that Phil Rushton, when no one is looking, picks his nose and eats with his elbows on the table.

    I am way too busy to find the reference that I am citing.

    Von

  93. #93 Sven DiMIlo
    December 22, 2009

    Sven. You are making a positive statement. You are making the claim that there is a genetic system that determines intelligence, that there is variation in the genetic system that determines variation in intelligence, and that this variation is partitioned by race.
    Prove it.

    um, what?
    Apologies for gumming up the conversation you’re having with the one I’m having, but honsttly, I haven’t made any of those claims, particularly the third. I came in up at #34, where I questioned a claim made by you. This one:

    there is not one shred of evidence connecting the process of developing any of the brain function that we measure with intelligence tests with genetic variation.

    and also, by implication, this one:

    it is impossible to imagine how intelligence can be inherited in such a way as to explain the variability we see in the most inter-group differences. That there is some genetic component is not impossible, but it is very hard to maintain the idea that it is genetic and ethnic, or genetic and racial, or genetic and explanatory of more than a few IQ points in most people. There are no genes, there are no developmental mechanisms, that have been identified.

    (yeah, both from the OP; yes, the one up at the top)
    Then I responded to your condescending reply at #49 where I cited primary literature that seems to refute your claim. Also I questioned a claim made by anther guy, viz.

    It is impossible for variation in alleles to have much to do with variation in intelligence

    Why is it impossible? is my question. I do not understand the reasoning behind these assertions.
    You are certainly correct that all I have done is to express my surprise that you guys really think that, and to express my ignorance of the relevant literature. I explicitly asked for references that might help alleviate my ignorance.
    For this i am compared to denialists and racist trolls?

    Bite me.

  94. #94 Elfie
    December 23, 2009

    Sven, I think most of the long time people here are jaded out of their fucking mind. They’ve seen a lot of trolls, so it’s understandable if they’re quick to stereotype commenters.

    Ultimately, there’s not a chance in hell of having a reasonable discussion here in the comments. Maybe someone, somewhere has done it – but I’d stick to face2face discussions if you want to actually have some meaningful conversations on these things (which are interesting, relevant topics that are very, very complicated).

  95. #95 Bryan
    December 23, 2009

    Ignoring rushton, I think I linked here to a meta-analysis of the brain size / iq relationship. It didn’t focus on race differences, but the studies used MRI’s or some other imaging technique to measure brain size more precisely. And, it does relate to IQ (something like .30 effect size).

    I remember reading an article claiming that it was gould who fudged the data re measuring morton’s skulls. Of course it appeared in one of them biased journals (PAID– not intelligence).

    Rushton and Jensen do have a 60 page review of race difference evidence wherein they focus on skull size differences from many sources. The article was published in an APA journal, so the usual bias claims don’t apply.

    Is anyone finding the debate here useful (i.e., feel like they’re seeing new info or points of view). It does seem like we reached a death spiral where the diminishing returns of further posts seem low.

    I do believe I linked to some evidence– my study on ECTs for example.

    I’m surprised no one’s yet brought up the “define race now with 100% precision or admit it doesn’t exist” card.

  96. #96 bad Jim
    December 23, 2009

    My parents were pretty bright, and my siblings and I are pretty bright as well. It’s reasonable to suppose that our intelligence was to a considerable degree inherited. Our genes aren’t the only things we inherited, though; we inherited our parents themselves, our mother’s womb, their loving care, their income stream, their education, their library, their parents and siblings and cousins, our country and its history and institutions. It would be rather churlish of me to insist that, of all the advantages I inherited, in comparison to someone born in less privileged circumstances, whose parents and grandparents were denied full citizenship and the possibility of education, the main difference is a sperm and an ovum and not the couple who produced them and raised me.

    Sure, genes matter. We aren’t rats or lobsters. But the environment is likewise all-powerful: we weren’t starved.

    We humans exhibit some sexual dimorphism, and men’s and women’s brains have some discernible differences, apparently. Many among us continue to entertain the notion that women are incapable of matching men at the highest levels of intellectual achievement, though women routinely exceed the limits assigned them whenever they’re permitted to participate. In fact, the performance of men and women tend to track that of the social groups to which they belong.

    It doesn’t seem that we know enough about the relationship of “intelligence” with either sex or “race” to have a useful argument yet. It’s an interesting subject, there’s lots of new information coming in, and we ought to be content to sit back and wait for results. Instead we have vociferous debate. It’s not as though we had immediate questions about educational policy to decide; in fact, past policy decisions about the educability of different groups has quite likely have been skewing their relative performance for centuries.

    We should stop doing that.

  97. #97 Pen
    December 23, 2009

    I would have a great deal of difficulty believing that Africans have an average IQ 30 points lower than Europeans on average. That seems like a big enough difference that you should be able to notice it just by hanging out with Africans. Like the argument for male versus female height where you don’t actually need a study to tell you that males are taller in general, regardless of outliers. But the thing about hanging out with Africans is that you don’t notice such a difference. Cultural differences, different responses and approaches to problems, yes, but not broad general differences in intelligence.

    The argument in the other thread about contraception, for example, was absurd. There is no human lifestyle that doesn’t require at least that much capacity for planning and forethought.

  98. #98 gwen
    December 23, 2009

    My dad was very bright, as was my mom. She was also a vocal atheist. Looking around at relatives, I believe that the time they took to encourage my curiosity has more to do with my intelligence than anything else.I am African American. My IQ is well over 100. All of my (now adult) children have IQs of well over 100 (they attended private schools where IQ measurements were allowed). I have a brother who tests in the genius range. In my workplace full of bright and knowledgeable people, I am acknowledged to be very bright and knowledgeable, even while they look down on the intelligence of other African Americans and non-whites we interact with in the course of a day–much to my frequently vocalized frustrations. People seem to do a disconnect between the African American they know vs the African American stranger. Although anecdote is not data, I know plenty of very bright African Americans,as well as bright members of other ‘races’ (don’t get me started on the validity of ‘race’), I also know plenty of incredibly stupid African Americans as well as stupid people of other races.
    I once had a doctor ask me why there were so many ugly African Americans (honestly, he asked me that). I stated that there are just as many ugly whites, but that he just didn’t look at them. I then pointed out to him over the course of a year (long after he cried ‘uncle’), all of the less than beautiful whites we saw in our day to day interactions with the public. I think the IQ issue is much the same.

  99. #99 El Guerrero del Interfaz
    December 23, 2009

    Great post!

    And consistent with reality. For instance, I don’t know in the US, but here in Spain we are having more and more people with Down syndrome graduating from college. And with great grades at that.

  100. #100 seedsaside
    December 23, 2009

    I’ve not been reading through the whole comments, so I don’t know if anyone pointed this out already… But there’s also something to get about heritabilities that becomes quite interesting when we are in a situation where heritabilities relies strongly on genetic differences. Basically, it means that variance in (usually additive) genes explains most of the phenotype. If there’s such genetic variation within a set of populations or a species, it basically means that the characteristic is not selected for. The only alternative would be a quite complete structuration of genes that would otherwise be seen via molecular markers (which is clealr y not btw).
    If intelligence variation in H. sapiens were mainly due to genetics, it would mean that smart people would have no particular reason to be proud of, as it would be of no interest evolutionarily speaking. (That’s interesting because proponents of group thinking often make claims of evolutionary elitism they should better forget…).

  101. #101 Greg Laden
    December 23, 2009

    Well, good morning. I’m still waiting for evidence of genetics connected to intelligence.

    Seeds : Yes, I made reference to that in connection to the number of heads one has!

    Pen: As someone who has lived in Africa, I always want to ask these people who push for the difference if they’ve ever met an African.

    Then my next thought is often “Did you talk, honestly and openly about your feelings, to the African you met.”

    Then my next thought is often “Did the African whup you upside the head.”

    But that’s just my own personal fantasy.

    OK, folks, continue with the discussion. I’ll be checking back every day or two for evidence of a gene-IQ link. I’m writing a piece on this and I’d love to find out what the heck the “Whites are Better than Blacks” crows is offering new these days. If it’s convincing, it will change the conclusion of my piece and you get to be in the acknowledgments.

    Remember: Group differences itself is no more evidence of the link than group correlation to speaking a specific language is evidece for a “language gene” that determines French vs. Farsi.

    Remember, linkage to a physical trait that itself lacks a clear genetic connection is not evidence either. Remember to check the direction of the causal arrow, and remember that there must be a physiological mechanism having to to with neural ontogeny that you can specify, because we’re talking brains here.

    OK, folks OFF TO THE LIBRARY!

  102. #102 Robert Bruce Thompson
    December 23, 2009

    Bob: I think the issue there is two fold. 1) The racialized IQ standard existed for 60 years or so as a to parter: Whites = 100 points, blacks = 85 points, Africans = 70 points, and the black IQ is the result of Africans getting fucked now and then by their white owners. Totally racialized, totally genetic. Then, 2) The adding in of a Asian morphology with five or six points more than the White IQ gave cover for the racialized anti-Black version.

    Which, by the way, you knew, and it’s kind of obnoxious that you ask like you’ve never heard this before, but whatever.

    It’s not obnoxious because I didn’t know it, and I still don’t know it other than in the sense that you assert it. And, anyway, I wasn’t asking a question. I was making a statement. In other words, “I wonder” at the confused thinking of people who accuse those who argue in favor of racial differences in IQ, despite the fact that those arguing in favor of racial differences attribute the highest IQs to those who are generally not considered to be favored groups among white racists, to put it mildly.

    Yes, it’s true that African blacks have a mean IQ of about 70 on an SD15 scale, and American blacks about 85. But if you consider the mean Chinese IQ advantage of half a sigma to be a minor difference, you don’t really understand a normal distribution curve. I note that you ignore the Ashkenazi advantage of a full sigma, which is simply huge.

    Those differences pile up as you get further and further from the mean. Run the numbers and you’ll see what I mean. Those of Ashenazi Jewish heritage make up a tiny fraction of the overall population, but disproportionately represented as you get out to IQ 160 (only +3 sigmas for them, versus +4 sigmas for the general population) and higher. That’s the best explanation I’ve seen of why Ashkenazi Jews are so heavily represented among Nobel Prize winners in the hard sciences and other intellectually demanding pursuits.

    It’s also evident in just about any other proxy measure of intellectual ability. Check out, for example, the representation of Ashekenazi Jews and Chinese on the hard science faculties of just about any college or university, or the heritage of top SAT scorers or national science fair winners. These are observable facts, and facts do not require justification. Observing and stating those facts is not racist, as much as you want it to be.

    As you know (or should know), in a pure meritocracy, IQ correlates more strongly with success than any other metric. In intellectually demanding disciplines, IQ correlates overwhelmingly with success. As much as you wish it otherwise (and I do as well), Ashkenazi Jews and Chinese are always going to be overrepresented and blacks underrepresented among our best physicists and chemists and mathematicians, just as Ashkenazi Jews and Chinese are always going to be underrepresented and black Kenyans overrepresented among our best Marathon runners.

    The real question is why this matters so much to you. It’s simply a fact of life, and all the wishing in the world isn’t going to change it.

  103. #103 toto
    December 23, 2009

    Greg, seriously, you need to read up on “heritability”.

    1) “Twin studies” mostly consist in comparing “true” (monozygotic) twins and “fraternal” (dizygotic) twins. Surely you knew that? The reason I ask is that much of your post makes no sense if one assumes that you do.

    Example:

    But twins are raised together in the same environment. So they have the same language, the same cultural customs, the same geography etc. That they have the same IQ is not surprising.

    Exactly. And accordingly, nobody is surprised that twins have similar IQ. The surprising fact is that MZ twins have much, much more similar IQ (and height, and other things) than DZ twins. That’s despite having “the same language, the same cultural customs, the same geography etc.”, as you put it.

    Example 2:

    Does everyone understand why that is the case? Familial or cultural causes may be very strong but not genetic.

    And accordingly, they are not expected to show up in properly made twin studies.

    There are many good reasons to be sceptical bout twin studies (epistasis, maternal factors, the known fact that MZ twins spend much more time together, etc.), but none of those you cite are.

    2) You assert, without references, that the heritability of ability for language is “undefined”. Well, some folks have actually looked at the data. They found a positive result. Maybe they’re full of it, but perhaps you could point us to a reference for that?

    3) You don’t provide any sources for the fact that speaking a particular language is highly heritable. This amounts to saying that MZ twins should speak the same language much, much more often than DZ twins. That’s not impossible, but I’d really like to see a reference for that – it does seem a bit counter-intuitive.

    AFAIK, the “consensus” value for (genetic!) heritability of IQ lies between .3 and .7. That includes people like James Flynn, of “Flynn effect” fame, who has spent his life working on these questions. Could you please read his books becore calling him a racist?

  104. #104 Greg Laden
    December 23, 2009

    Yes, it’s true that African blacks have a mean IQ of about 70 on an SD15 scale, and American blacks about 85

    That is simply and demonstrably untrue. See my comments above for the source of this information. Replication is the hallmark of good science. Saying an untruth over and over does not count as replication.

    Toto: I am well aware of the meaning and nature of the term “heritability”. You are correct that in the context of twins, there would be no difference between twin types and language spoken. But that is not the reason I brought that up as an example. The language spoken example serves as an example of something else.

    Your comment linking to Stromsworld is interesting but it is about disorders. Therefore, it is not related to any of the current questions. Do you understand why that would be?

    AFAIK, the “consensus” value for (genetic!) heritability of IQ lies between .3 and .7. That includes people like James Flynn, of “Flynn effect” fame, who has spent his life working on these questions. Could you please read his books becore calling him a racist?

    Connect this assertion, in three separate considerations, to these two different things: 1) The specific evidence (and here you will have to take apart the so called “consensus” and look at specific studies” liking a system of genes to a phenotype measured with IQ tests (you will find a great lacking of a direct connection for most studies) and 2) make the link between inherited features of IQ and racial groups (this will in all cases I know of be a presumption and nothing else) and 3) discuss the relationship between those numbers (.3 and .7) and actual IQ differences. In other words, there can be a very high heritability coefficient for a very small difference, or there can be a very large difference with a very low heritability coefficient. In still other words, people are claiming black IQ = 70, white IQ = 105, and this is determined by genes. Show us how the information on which your “consensus” is based leads to that specific model.

    Your comments are always so obnoxious yet so devoid of valuable content. And so unabashedly racist. See if you can do better this time. Try to do it without telling me what you think I have not read.

  105. #105 Katharine
    December 23, 2009

    Until much more progress on this is made, I’m coming down on the side of Plomin, Martin, etc.: it’s about half genetic and half environment.

    Greg, in addition, how do you account for people who are outliers in terms of IQ, on the right side of the curve? How does environment affect that? This is something that your answer doesn’t seem to account for, and one which I’m sort of curious about the mechanisms of.

    I’ll use myself as an example: I’m the offspring of two middle-upper-middle-class parents, with IQs of 116 and 141. My IQ was measured to be high enough (keep in mind, this measurement was done in the mid-90s and without the Stanford-Binet V, but with tests with lower ceilings, so no exact scores were given) that estimates ranged anywhere from 165 to ‘well above 180′. I was given a pretty good environment, although I wouldn’t say it was ideal, to explore, but I’d say I went through a considerable amount of hardship as a kid – I was the youngest in the class for a considerable amount of time, since I skipped a grade when I was a kid, which was one of the contributors, besides a rather miserable home life which I’m not going to get into too much, to depression that lasted 20 years which impacted my first two years of college and resulted in me having to transfer out of TWO schools before being successfully treated; I am now doing fine with a solid 3.3 average and I’m a neurobiology student. There is still, I admit – and I’m in a safe emotional place to do so – some collateral still from that period of time – there are some specific struggles, such as peer issues and societal issues, that affect people with a high enough IQ (for one, there’s an issue which Australians deride as ‘cutting down the tall poppies’, and rightfully so, because individuals with the ability have the right to succeed to the best of their ability and be the cream of the crop). Presumably the fact that I grew up in a financially stable family was somewhat of a buffer against the condition getting much worse.

    Add to that the fact that within families, IQs can vary quite a bit between siblings if they’re not identical twins or even twins.

    My point here is, to tie it in with the discussion, that environment doesn’t TOTALLY account for IQ; there is a component that accounts for significant differences, and I’m inclined to believe that it’s genetic to a significant extent; I have wondered, frequently, if part of it is epigenetic or caused by the gestational environment, and I don’t know much about that, but it’s not entirely environmental.

  106. #106 Greg Laden
    December 23, 2009

    Katherine, I think you have this backwards. Never mind you or me (we both have off the chart IQ’s obviously, and are parents are merely “smart.”) Consider that IQ tests have shown a steady and regular increase in the US over 100 years. If IQ variation is 50% genetic, and if the IQ measurements are valid, both assertions you are making, then smart people are somehow surviving longer or having more offspring, or dumb people are getting killed off or something, at a rate per generation that should be fairly obvious.

    Is i obvious? Can you show me the demographic scenario by which this happens? Are you working on a PhD? That would be a great thesis project, to test that hypothesis. (And it IS your primary working hypothesis, it would seem.)

  107. #107 Alex
    December 23, 2009

    Good post. Seems to have pissed off a few people in the comments too. And you didn’t even have mention that there’s no reason to think that intelligence can be measured by a single number anyway.

    In intellectually demanding disciplines, IQ correlates overwhelmingly with success.

    Define “intellectually demanding”.

  108. #108 Stephanie Z
    December 23, 2009

    Katharine, your understanding of environment is incomplete. So is that of plenty of other people, but I’m picking on yours because you’ve articulated the misunderstandings so well. The interaction between individual and environment is not one-way. Since we’re using personal examples, I’ll use my family.

    I’m the oldest child and was a decently cute baby, not fussy. There are pictures of me everywhere, and I had undivided attention for two years. My middle brother showed up when I was learning to say, “No,” which didn’t go over well with my authoritarian father and affected his ideas about parenthood. He also reacted to something my mother was eating, probably chocolate, which made him fussy and gave him an ugly rash. My youngest brother was ridiculously adorable, as well as being the hope for “saving the marriage.” Since that didn’t happen, he barely knew my father.

    We were all born in the same state, but we spent very different parts of our developmental lives moving to various parts of the country and in different school systems. We graduated from three different high schools (sort of–one GED in there). We faced different levels of independence and responsibility at different ages. In short, our environments weren’t consistent. They were shaped by timing and by our own traits.

  109. #109 Penelope
    December 23, 2009

    Define “intellectually demanding” (profession).

    Apparently, psychometric expert would not be included.

  110. #110 Alex
    December 23, 2009

    Katharine, anecdote is not data.

  111. #111 mary d
    December 23, 2009

    how about comparisons of males v females in societies where women do not share education– literacy, etc.? Even here in the US, I recently saw an article about girls’ not achieving in math because of cultural issues. I do see girls generally excelling in elementary school but then in high school, college, and grad school, not so much… or women getting PhDs in often not-very-demanding areas like education. Of course, IQ an achievement, even intellectual attainment, are not the same thing.
    I do diagnostic testing in mostly elementary schools and work with student that age, and I have wondered why the WISC has the same scoring protocols for boys and girls. It seems to me that boys are as a group, more extreme, with more outliers in both directions. (I know I may take some heat for this– it has just been my observation.) These tests are not very nuanced, and I have read reports based on scores alone for kids I know well that make the child unrecognizable.

  112. #113 Robert Bruce Thompson
    December 23, 2009

    It seems to me that boys are as a group, more extreme, with more outliers in both directions. (I know I may take some heat for this– it has just been my observation.)

    There’s no good reason you should take any heat for that comment, but I’m sure you will.

    Your observations are in accord with the fact that the standard deviation for women’s IQ scores is smaller than that of men. (The mean IQ of women is also between 0.5 and 1 point lower than the mean IQ of men, but that’s too small to be significant.) Because of the smaller sigma for women’s IQ scores, women are overrepresented relative to men at and near the mean, and underrepresented on both ends of the curve. In other words, women are more likely than men to be slightly brighter or slightly stupider than average, but less likely to be extremely bright or extremely stupid. That’s at least part of the explanation for our prison population being mostly male, as well as for the overrepresentation of men in the hard sciences, engineering, and other rigorous disciplines. (Of course, the fact that, on average, men are more aggressive than women is also part of the explanation for both phenomena.)

  113. #114 Robert Bruce Thompson
    December 23, 2009

    Define “intellectually demanding”.

    Okay, as a starting point for discussion, how about rigorous disciplines that require abstract thinking and in which hypotheses are falsifiable and results are verifiable rather than a matter of opinion? Mathematics, say, or physics, chemistry, and engineering.

  114. #115 Irene
    December 23, 2009

    The chemist says that chemistry is on the short list for most intellectually demanding.

  115. #116 daedalus2u
    December 23, 2009

    What I find to be one of the most pernicious and destructive aspect of IQ racism is that the racists then use it to justify racist bigotry and behaviors which are otherwise indefensible (and indefensible even then).

    There is enormous evidence that environmental enrichment results in higher IQ (I will use IQ even though IQ is too narrow and isn’t a sufficient measure of cognitive ability). Even if IQ were as much as 80% “genetic” (we know it isn’t because of the increase of IQ over time), the genes a person has are immutable. A person’s IQ can’t be modified by changing their genes; it can be modified by changing their environment. The question is then, if a high IQ is so great and produces a high GDP, shouldn’t we as a society be doing everything possible to raise the IQ of everyone by every possible means?

    We know that there are lots of things that correlate with lower IQ and which are not genetic but are environmental; prenatal care, parental age, parental education, maternal nutrition during gestation, heavy metal poisoning, alcohol use during gestation, stress during gestation, violence during gestation, lousy daycare, lousy preschool, lousy kindergarten, lousy elementary school, poor nutrition, poor health care, etc.

    If one wanted to raise the IQ of the nation, and by doing so increase the per capita GDP, wouldn’t dealing with the things that we know how to fix be something to try? We know how to provide prenatal care. We know how to provide a nutritious diet. We know how to provide lots of things that are not being provided and we know that IQ’s are going to be lower as a consequence.

    It seems to me, that proponents of high IQ as being a factor in per capita GDP should be focusing on trying to provide things which we know will increase average IQ and not on things that are immutable such as genetics.

    For the most part, the proponents of high IQ are not focusing on trying to improve the environment so as to raise the average IQ by known methods. Instead they are focusing on genetics so as to deny the importance of environment, so as to not implement environmental changes that we know will have positive effects. To me, this is pretty good evidence that for many of these proponents their actions are in some way the products of xenophobic feelings and not due to rational thinking.

  116. #117 daedalus2u
    December 23, 2009

    I would argue that mathematics, physics and even chemistry are not that “intellectually demanding” because they are about things which are constant and fixed. Math and physics don’t change over time the way that people do. Computers can be programmed to do math and physics. How can that be “intellectually demanding”?

    Understanding written language is something that is hard. Understanding spoken language is harder still, body language is even harder. Many people don’t even know what their body language is saying about themselves.

    Can computers be programmed to understand body language? Not at all. Are some people much better at it than others? Yes, of course. Some of those people are so good at it that they can both read and project body language at will and use that body language to manipulate other people without their understanding. We call such people “charismatic leaders”.

  117. #118 mk
    December 23, 2009

    “intellectually challenging/demanding”:

    self reflection, the ability to recognize when you are wrong and take steps to correct it, rigorously challenging your own preconceptions, humility.

  118. #119 Bryan
    December 23, 2009

    The most well-regarded twin study actually looks only at twins raised apart (separated at birth for whatever reason– one twin goes to live with grandma; perhaps, the other twin is adopted).

    Granted you can still make the argument that maybe the separated twins environments are still somewhat the same (if both are still raised in poverty or both in upper class homes, for example), but it’s not as bad as Greg claims (Greg seems to think that environment is completely confounded with shared DNA as the twins are raised in the same home. Not true, at least in this classic ongoing study).

    Also, two key parts to the data that I don’t think Greg’s world view can explain:

    1. Heredity tends to increase with the age of the twins (ironic, as with increased age the environment supposedly has more time to affect IQ).

    At young ages H is relatively low and C (environment) is between 25-50%. As adults, C typically drops to zero (!) while H rises to 75% or so. That’s a staggering example of imbalance between the conventional wisdom that it’s both nature and nurture.

    2. Adoption studies show consistently that the best predictor of the kid’s iq is his/her biological mom’s IQ (even though obviously the kid hasn’t been raised by mom, and likely doesn’t know who mom is).

    The correlation between the adopted parents’ IQ and the kid’s IQ is near zero. So too is the correlation between the adopted kid’s IQ and his/her (non biologically related) siblings raised in the same environment.

  119. #120 Bryan
    December 23, 2009

    Comment above:
    I do diagnostic testing in mostly elementary schools and work with student that age, and I have wondered why the WISC has the same scoring protocols for boys and girls. It seems to me that boys are as a group, more extreme, with more outliers in both directions. (I know I may take some heat for this– it has just been my observation.)

    IQ tests are made on purpose to show no sex differences. Males and Females both have a mean of 100. It’s easy to do. If any one question shows a sex difference one way or the other, the question is tossed. By definition, then the IQ test won’t show mean differences (but still shows the variability difference mentioned above).

    A point I made recently is that using an IQ test to check for sex differences is kinda stupid. Instead, I showed a 3 point “iq difference” across the sexes on elementary cognitive tasks (described in a post above) even though no differences existed (go figure) on a paper and pencil IQ test.

    An interesting side note– if we can equate IQ scores for males and females, why not do the same with race groups? The problem is the test items you have to throw out are the most g-loaded (i.e., the best measures of intelligence in the exam), so you end up with a test showing no differences because it does not measure g, and then does not possess any validity. BTW, this has been known for awhile– it’s called the spearman hypothesis.

  120. #121 daedalus2u
    December 23, 2009

    Bryan, all twins share the same in utero environment. We know that lots of neurodevelopment happens in utero, and that neurodevelopment can be affected by environmental stimuli. For example maternal nutritional deprivation increases the incidence of schizophrenia. Maternal psychosocial stress increases the incidence of autism. Maternal exposure to violence produces an increased violence phenotype. Ambient sound can be heard in utero.

    It is in utero that the major neurological structures are formed. Why wouldn’t there be gigantic effects from the neuroanatomy that occurs during that in utero experience? Effects of that shared in utero environment get labeled “heredity”, but it is not genetic.

  121. #122 Raging Bee
    December 23, 2009

    I do have a strong opinion on race differences on IQ tests– they exist and have important consequences and cannot be explained away by the obvious things everyone always brings up (test bias; SES differences, etc).

    Really? Differences on IQ tests can’t be explained by family environment, parental education-level and example, quality of schools and teachers, social/cultural influences, availability of opportunity, etc. etc.?

    Yeah, Bryan has a strong opinion: he’s determined to use whatever sophistry he can to justify his unshakable gut feeling that “those people” will never be as smart as he is. And despite his valiant efforts, he still ends up flushing his credibility down the toilet with the above-quoted paragraph.

    This is where eight years of radical-right misrule have got us: flat-out racism is slowly but surely becoming respectble again.

  122. #123 daedalus2u
    December 23, 2009

    I suspect that the reason H effect on IQ seems to increase with age is because it reflects the underlying gross neuroanatomy which occurs in utero. That underlying neuroanatomy reflects the ultimate cognitive processing ability of the brain after the plasticity has been “used up” in language acquisition and the learning that occurs in the first few decades of life.

    Of course twins adopted and raised apart, likely were adopted through some sort of agency which has criteria for choosing of adoptive parents. The mother who can choose a “better” agency to submit her children to for adoption will have her children adopted by “better” adoptive parents; the mother who can’t choose, or who has her children taken away by the state because they are born addicted to drugs will have her children go to different foster parents.

  123. #124 Bryan
    December 23, 2009

    I agree that twin studies don’t control for pre-natal environment. That’s one reason I’m not claiming genetic differences (despite Greg’s insistence that I really really want to, but am afraid).

    I do think the differences are biological. That still doesn’t to me equate to genetic. So, I’m agnostic until more evidence comes in (or I’m sitting here swathed in swastikas and hoping me toning down my writing will fool the clever scientists).

    I wonder about the prenatal thing though– I am no biologist. Would it explain why identical twins versus fraternal show marked differences in the twin study correlations (always strong IQ correlations for identical twins, followed by fraternal, followed by non-twin siblings).

    Is there a mechanism in the prenatal environment that would explain why identical versus fraternal twins show this convergence?

  124. #125 Bryan
    December 23, 2009

    A few people here comment I keep flushing credibility. I wonder if lurkers or other contributors could post their reaction to the debate so far. I guess that ranges from BP is a racist ass, to it seems like he’s onto something.

    Feedback needed / appreciated.

  125. #126 Bryan
    December 23, 2009

    Consider the Wonderlic (an 12 minutes IQ test used to hire people– taken by over 100 million people, and in the news every year as it’s given to NFL draft players).

    It’s manual shows a range of IQ for any job. The idea is unless your iq is in the range, you won’t do the job well.

    Here’s some examples:
    Janitor 85
    Cop 100
    CPA 115
    Rocket Scientist 130

    So, a janitor needs a minimum IQ to do his/her job well. Lower than that and he/she will fail with high probability.

    A cop needs a 100.

    The IQ mins rise with job complexity (this has been replicated by 100s of studes).

    The Wonderlic also suggests that one can be too smart for the job. A guy in CA applied to be a cop but scored like 122. The city refused to hire him because he was too smart.

    He sued; it seems like a stupid argument.

    The city countered: We have a limited budget; it takes 10,000$ to bring a recruit through training so that he can work. We have data showing that people with IQs that are too high tend to be flight risks (they stay a year or two, become bored and then move on). This means we have to re-spend the time effort and money hiring someone else. So, we don’t accept people with too high IQs, just like we don’t accept people with too low IQs.

    Guess who won the case?

  126. #127 Bryan
    December 23, 2009

    Sorry for the typos in the last post; I am spending less time proofing em.

  127. #128 Raging Bee
    December 23, 2009

    Bryan: you’ve been getting feedback ever since you started posting here — and your only response seems to be to repeat the same old assertions over and over, and/or change the subject. (“The Wonderlic?” WTF does that have to do with anything?) Why are you now pretending you haven’t been getting any? Looking for validation after your arguments got debunked by the first round of feedback?

  128. #129 Bryan
    December 23, 2009

    Someone wanted evidence of IQ needed for complex jobs, so I provided it (the Wonderlic is an IQ test).

    I saw no debunking, but appreciate your perspective.

  129. #130 mk
    December 23, 2009

    Bryan,

    You made it very clear you think the white “race” is more intelligent than the black “race.” (White supremacist much?) In my book, that’s rank stupidity. And your continued “I’m just sayin!” gambit is getting–again, to me–tiresome.

  130. #131 Raging Bee
    December 23, 2009

    I do think the differences are biological. That still doesn’t to me equate to genetic.

    In other words, you’re still looking for an excuse to pretend the races are innately different in some “biological” way, even though you can’t actually demonstrate such a diffference.

    So, I’m agnostic until more evidence comes in…

    Sounds to me like you’re ignoring the existing evidence and pretending you need more evidence. Why not do what REAL scientists do — draw a conclusion based on the available evidence? Care to tell us what conclusion the currently-available evidence supports, in your opinion?

    …(or I’m sitting here swathed in swastikas and hoping me toning down my writing will fool the clever scientists).

    And while you wait for evidence, you’re playing the self-pity card in your spare time.

  131. #132 mk
    December 23, 2009

    “Someone wanted evidence of IQ needed for complex jobs, so I provided it (the Wonderlic is an IQ test).”

    Really? I just went back and was unable to find anyone asking for that. I may have missed it, though. Could you point out who you were providing that information for? Thanks.

  132. #133 Bryan
    December 23, 2009

    You guys seem to be mis-characterizing lots of what I say.

    I said there’s a mean difference favoring whites over blacks on IQ test scores.

    That’s a fact; it’s undeniable; The EEOC recognizes it; so too does the US federal court. The very existence of the difference caused the supreme court to create a new type of discrimination– adverse impact– to make the difference illegal unless the employer could show the test predicted job performance.

    Griggs vs. Duke Power 1971 (griggs scored low on the Wonderlic and so didn’t get promoted. The court ruled that even though the discrimination was not intentional, the IQ test created a “disparate impact” against blacks. Since Griggs, employers must show that their IQ test (on which blacks score lower) is job related otherwise it would be illegal to use them). If blacks dont score lower on IQ tests than whites, why is SCOTUS correcting a problem that doesn’t exist (and why did griggs sue and then win, and why did congress then amend the civil rights act to include this idea?!).

    You’d have to be wholly ignorant of lots to not know that a black white difference exists on *iq tests scores*.

    Facts are facts and can’t be racist. If one explains the difference by saying that IQ tests are biased crap. Is that racist?

    Greg:

    I demonstrated the difference in my very own study– speed of response / perceptual intake. It completely mediated the paper and pencil difference. I take how fast a neuron fires to be fairly biological, but not necc. genetic.

    I’m posting evidence; you’re ignoring it.

    You’re really claiming that a real scientist must draw conclusions on everything now / can’t be agnostic until more data are in? I’m glad you’re not doing clinical trials.

    To the person who couldn’t find the request for more info on IQ and job complexity, perhaps google whack it.

  133. #134 Bill James
    December 23, 2009

    [131]

    In other words, you’re still looking for an excuse to pretend the races are innately different in some “biological” way, even though you can’t actually demonstrate such a difference.

    Physical characteristics?

  134. #135 Greg Laden
    December 23, 2009

    Bryan, I find this rather orwelian. I ask for specific evidence that would underwrite the idea that African = 70, White/Euro = 105, Afro-American = 85 (or thereabouts for all these three numbers) being genetic.

    You then say

    I take how fast a neuron fires to be fairly biological, but not necc. genetic.

    I’m posting evidence; you’re ignoring it.

    Huh?

    BTW, I am not denying the group differences, just to be clear. You and I are agreed on that, and we are agreed on the fact that it is important. I am unclear on what your position is on the genetics. I’m not sure you are being consistent.

  135. #136 Greg Laden
    December 23, 2009

    Bill, in what way do physical characteristics indicate racial groupings? Before you answer that you should probably define what you mean by race, because that is often left out of such discussions early on and that causes problems later.

    You might want to refer to this:

    http://scienceblogs.com/gregladen/2008/12/the_scientific_political_socia_1.php

  136. #137 mk
    December 23, 2009

    Bryan,

    IQ tests are bullshit. Deal with it. Now shake it off and try to get over your need to be superior to dark skinned human beings. The white “race” is not more intelligent than the black “race.” And one more time, stop with the “I’m just saying” gambit.

  137. #138 Raging Bee
    December 23, 2009

    I said there’s a mean difference favoring whites over blacks on IQ test scores. That’s a fact; it’s undeniable…

    It’s a fact that can easily be misinterpreted and misused if it’s taken out of context and in a vacuum, as you are now taking it.

    Facts are facts and can’t be racist.

    That’s the standard refrain of racists who ignore all the non-racist facts that don’t support their racism. Facts themselves are not racist, but racist cherry-picking and quote-mining of facts IS racist.

    You’re really claiming that a real scientist must draw conclusions on everything now / can’t be agnostic until more data are in?

    No, I’m reminding you that you can draw provisional conclusions based on the currently-available data, with the understanding that conclusions may change if new data requires it. Your “agnostic” act is just an excuse to dodge the fact that the currently-available evidence doesn’t support the conslusion you want to draw.

  138. #139 Stephanie Z
    December 23, 2009

    Have to go back to Christmas prep, storm or no storm, but Brian is also being inconsistent in what information he’s claiming that IQ tests provide. Of course, that’s being consistent with most of the psychometricians in the area. He gets upset when I say IQ measures fit with industrialized institutions, then tells me it predicts what?

    He also fails to mention that the parsimonious explanation for correlations between various tests is test-taking ability.

  139. #140 Stephanie Z
    December 23, 2009

    Ack. Sorry. Bryan, not Brian.

  140. #141 mk
    December 23, 2009

    Oh and I’m sorry, but I’m not familiar with “googlewhack.”

    So again… Who asked you for that info?

  141. #142 Bryan
    December 23, 2009

    GREG: Bryan, I find this rather orwelian. I ask for specific evidence that would underwrite the idea that African = 70, White/Euro = 105, Afro-American = 85 (or thereabouts for all these three numbers) being genetic.

    ME: Perhaps part of the confusion stems from no quote function here.

    I will try to quote stuff more when replying.

    I was not replying to your specific comment above.

    I dont believe the african IQ of 70 is valid. It’s based on lots less data (the american black versus american white data are literally on 10s of millions of people going back 90+ years).

    I also believe that if the true african IQ is lower than the african american IQ, then that’s bonafide evidence of a strong enivironmental affect on IQ (another reason why I’m not ready to claim genetics).

    My claim that it’s biological still stands. You can trace the raw paper and pencil IQ difference back to race differences in performance on tasks requiring nothing but mental speed. Even the speed with which one neuron in the brain fires correlates with IQ.

    My measures are cognitive (reaction time) and not biological (some type of blood test or whatever) but I think the inference that choice reaction time reliably and validly measures brain speed is reasonable.

    I’m not trying to be evasive, really, though I do admit my post prior to this was snarky.

    Also, I did figure out the google whack thing. This is odd to me. I’m not the only one here pretending to be an authority on IQ (a science blog posting suggested readings and making strong supposedly educated comments about the field).

    Yet no one here knew what the positive manifold is– it was so foreign that one thought it might be a googlewhack.

    That’s embarrassing. Spearman discussed it 100 years ago and any first year student would know what it means. It’s like claiming expertise in evolutionary biology but not knowing what natural selection is.

    My point– it’s possible that some of the people who have devoted their lives to this topic see things differently then those outside the field. It’s possible that IQ researchers are not all idiots.

    The difference might be caused not so much by bias or racism, but by having read, absorbed, collected data on, analyzed and thought about these issues for a whole career (versus having read and enjoyed Mismeasure of Man).

  142. #143 Stephanie Z
    December 23, 2009

    No, Bryan. Positive manifold, while jargon, is not unfamiliar. Referring to it as a law is problematic in that it vests it with far more authority than even those in the field do.

    And there you go again, trying to attack my expertise instead of my arguments. Haven’t you figured out yet that you’re somewhere where those sorts of moves are transparent–and not appreciated?

  143. #144 Bryan
    December 23, 2009

    I’m for affirmative action; voted for barack (my first time voting in 22 years, because I found him so inspiring; not so sure about him today); and I believe that both the asian and jewish iq means are higher than the white IQ mean.

    But by citing the observation that if the races are given iq tests, a group mean difference will exist favoring whites over blacks– that makes me a racist.

    Provisional conclusions? I’d rather say I don’t know. It’s complicated; been studied for a century and I think many people would find that conclusion ok.

    I’d rather not feign scientific authority on a conclusion when I honestly don’t think a conclusion can be reached at this time.

    No vacuum here but if we cant get past agreement on the observation that there is a difference (Greg at least agrees) then we have nothing less to discuss.

    MK insists that I am claiming the white race is superior. I never said that; I commented very early that the distribution overlap shows that it’s trivially easy to find millions of blacks smarter than 10s of millions of whites.

    I don’t understand MK’s point about “I’m just saying”. Could you give me a concrete example?

    Heading out for now.

    Oh, happy holidays!

  144. #145 Bryan
    December 23, 2009

    Stephanie, I have the exact same perception about you/ most everyone here– attacking me versus my argument. Perhaps we both need to heal theyselves.

    The law reference is the fact that it’s never not been observed in any sample or study since IQ tests have been devised.

    Doesn’t make it a law, which is why people call it a “law”.

  145. #146 Stephanie Z
    December 23, 2009

    Bryan, care to point to a comment in which I’m attacking your qualifications instead of your argument?

  146. #147 Bill James
    December 23, 2009

    [136] Greg: The meat and potatoes of the post you refer is found at:
    The Scientific, Political, Social, and Pedagogical Context for the claim that “Race does not exist.” : Greg Laden’s Blog. I post it here for the curious as it was a broken link. We will now begin reading.

  147. #148 Bryan
    December 23, 2009

    I owe you an apology Stephanie; I looked back and nowhere saw you question my expertise.

    Sometimes long threads like these can be clarified if each side posts perhaps three specific questions that they feel the other side has ignored or glossed over.

    Can that be tried here, or should we just let the internet market sort out where this thread goes from here?

  148. #149 Kathleen
    December 23, 2009

    Greg,

    I’m not a scientist, a researcher, nor am I the most intelligent person responding on here but what I do know is Bryan, having been married to him for 13 years. I think I am more than qualified to say, he’s not a racist nor is he a sexist.

    The comment from Stephanie was nothing less than a childish attack which was uncalled for, my name is often abbreviated, could be a sign of affection or have no meaning other than being faster to type, why a scientist would get their panties in a bunch over that seems a tad silly to me and completely side stepped the whole purpose of him writing in the first place.

    Seems to me, Bryan became labeled right out of the gate and anything he has to say or ask is attacked rather than looked at in a rational, reasonable way. Not at all in a way I would expect people of your status to behave. I would think scientists would love to have questions, to help educate the public, to show that they are reasonable and approachable, these comments don’t in any way show that. (looking at this as a parent and how I would want the scientific world to be viewed by my children)

    How do you suppose IQ be tested?
    Do you disagree that a person’s IQ can determine what type of job they are best suited for?
    If IQ tests had no value, why are they used so often?
    Why do companies use IQ tests, wouldn’t using them be discrimination?
    Are people born with the same IQ and that the environment they are raised in is the only thing that determines as they grow, whether they’re IQ goes up or down?

    These are basic questions, nothing racial about them, no if you’re black, white, male or female references.
    I suspect that instead of answering the questions the theme will be: Bryan had his wife defend him, she’s just as racist as he is (and maybe I’m just as sexist as well) and just side step giving an answer backed up with some evidence as to why your idea of IQ testing works better than the way it is done now.

    *I was not asked, bribed, nor threatened in any way to write any of the above, it was of my own free will that I chose to write*

  149. #150 Barn Owl
    December 23, 2009

    Bryan asked:

    Is there a mechanism in the prenatal environment that would explain why identical versus fraternal twins show this convergence?

    Approximately 65% of monozygotic twins share a single placenta, whereas most dizygotic twins have two separate placentas. In the 40% or so of DZ twins who appear to share a placenta, it originated from two separate ones that fused secondarily. In MZ twins with a fused placenta, there may be so much anastomosis between the placental vessels that the twins become discordant in growth, and one or both may die in utero. This information comes from a clinical embryology textbook by Moore and Persaud, The Developing Human. Given that there are still a lot of unknowns about fetal membranes and the uterine environment in humans – enough such that multiple pregnancies are still riskier in terms of duration and outcome – I wouldn’t dismiss the possibility that differences in placental function affect brain development and intelligence.

    But yeah, IQ tests are crap, and if you’re still clinging to stereotyped notions of race and IQ, then I suggest that you read Ewen & Ewen’s Typecasting: On the Arts and Sciences of Human Inequality. It’s a long and detailed book, but since almost everyone posting here has an out-of-range superior IQ, it should be easy going for y’all.

    I mean, *I* was able to read the entire book, and I have absolutely no fucking clue what my IQ is, and I generally suck at standardized MCQ tests as well.

  150. #151 Greg Laden
    December 23, 2009

    Kath,

    I have said a few times now that Bryan and I agree on the existence of group differences. Bryan’s citation of the 70-85-105 paradigm is poorly informed, but that does not obviate groups differences. We agree that group difference are important. Bryan’s position on genetic contributions is still unclear to me because he has said conflicting things.

    Regarding your questions on IQ, I think you may want to rethink some of them. In government in the US these days we see the constant application of “free market” principles. Does the fact that they are used all the time make them a good idea or imply a broad applicability? No. People have just plain got that wrong and we are slowly finding that out. I could easily think of other examples of people saying the same thing for a long time and insisting that it be true, but that insistence not making it true.

    Since Yerkes, people have been saying IQ means something, let us use it, leave us alone! and others have been criticizing the process. The questions you raise merely ask for IQ to be accepted for a wide range of uses simply because you and a lot of other people think it should be. I’m afraid that is not sufficient.

    I do not believe that IQ is useless. Nor have I said so. I have stated quite clearly in my comments and in the original post where I think the psychometrics have been misused, and I patiently await the actual evidence (other than “it must be so”) for the genetic cause of the alleged pattern of African/White and “admixturue” IQs.

    I think you also should attempt to understand why people are asking you to acknowledge the implications of unmitigated race-based model building. Its nice to say that facts are facts, but it is not ok for a mixture of facts and conjecture built into an unsupportable matter to be thrust upon society as has been happening for a few decades now.

    A lot of us are kind of pissed about that and would like to the supporters of this crap learn a little humility (and scientific reasoning). Sorry to sound so harsh, but there are important things at stake here.

  151. #152 Stephanie Z
    December 23, 2009

    Kitten, I’d take your opinion on sexism much more seriously if you addressed it to me instead of Greg. Ditto for your opinion on childishness if you managed to avoid mentioning my panties, which also hurts your factual accuracy, since I’m not wearing any right now.

    As for your points of substance, what Greg said.

  152. #153 Adrienne
    December 23, 2009

    Greg, perhaps you should debate this with Razib Khan of Gene Expression. I believe Razib is one of those who believe there are differences in IQ among racial groups.

    And *big* kudos to you, Greg, for raising this very difficult and controversial topic on your blog and for not censoring those who are politely disagreeing with you. I’m also thankful that the Stormfronters haven’t arrived here en masse to swamp the comments with dreck.

    The way to get to the truth of this debate is to carefully discuss and examine the evidence for both sides. I’m definitely against censoring debates and inquiries, even if they might lead to conclusions that are uncomfortable or that go against the conventional wisdom.

  153. #154 Adrienne
    December 23, 2009

    Stephanie Z @152But yeah, IQ tests are crap.

    Citation needed.

    Also, do you accept the validity of IQ tests in determining whether is someone is retarded or not? Or “gifted” or not?

    What about the Supreme Court decision that murderers can’t executed if their IQ is determined to be below 70? Do you agree with that too? If IQ tests are meaningless, should all murderers be executed regardless of their possible level of intelligence?

    Let’s get real, folks. IQ tests aren’t crap. They just show some very uncomfortable patterns and differences between certain groups that we’d like to pretend don’t exist. They lead to some uncomfortable results and even potentially more uncomfortable questions and conclusions. Not the same thing as being crap.

  154. #155 Irene
    December 23, 2009

    Adrienne, what are the uncomfortable conclusions you refer to?

  155. #156 Stephanie Z
    December 23, 2009

    Adrienne, you’re talking to Barn Owl at #150–unless you’re concerned about my panties.

  156. #157 Adrienne
    December 23, 2009

    Sorry, Stephanie @156: oops, my apologies. No, no panty concerns here.

  157. #158 Adrienne
    December 23, 2009

    Jason @24:
    This is going to sound totally sappy but no matter how they’re inherited, each person, each race, has different qualities they bring forth. And these differences are valuable and can be celebrated, whether they have a genetic or an environmental basis. The one who doesn’t score so high on the type of intelligence measured by IQ tests is certainly intelligent in a way others are not. So is it such a big deal?

    Absolutely agree.

    Even Steve Sailer, who is currently the most popular HBD blogger and writer, admits that standard IQ tests were written by Europeans to test for what Europeans thought constituted “intelligence”. Now, at least, we have some research into the idea of “multiple intelligences”. People can have some amazing abilities that aren’t picked up by the typical IQ test (even as I believe that IQ tests are valid for testing certain human abilities).

    Irene @155:
    Adrienne, what are the uncomfortable conclusions you refer to?

    One of the biggies is that in order to do certain jobs or to master certain fields, you need a certain level of IQ. If your tested IQ is only 105, for instance, you could probably not hack it as a physics major in college.

  158. #159 Irene
    December 23, 2009

    Adrienne: That is what you are worried about? That some geek can’t have his or her dream job?

  159. #160 Adrienne
    December 23, 2009

    Adrienne: That is what you are worried about? That some geek can’t have his or her dream job?

    Yeah, actually. This is actually a very real and personal concern of mine. I have an “above average” IQ. I think around 125-130? I’m wondering if I could survive a master’s program in computer science. I’ve done OK in the intro and foundation classes, but I clearly do not have the spatial reasoning that some of my classmates do. Once I was the only female, and clearly at the lower end of the classroom “pack”, even as I survived the class.

    I majored in a science in undergrad, but not a “hard” science. I’ll admit it, I really struggled with college level physics. I’m wondering if I could progress only so far in CS and then I’ll hit a wall I can’t get beyond. Only one way to find out, though, right?

  160. #161 Andrew
    December 23, 2009

    This is why the common wisdom in education is to not tell people their IQs.

  161. #162 Bryan
    December 23, 2009

    Thanks Barn owl. That was informative and seems like a viable thing to study for those interested in the nature/nurture of IQ (or anything).

    Quote:

    Absolutely agree.

    Even Steve Sailer, who is currently the most popular HBD blogger and writer, admits that standard IQ tests were written by Europeans to test for what Europeans thought constituted “intelligence”. Now, at least, we have some research into the idea of “multiple intelligences”. People can have some amazing abilities that aren’t picked up by the typical IQ test (even as I believe that IQ tests are valid for testing certain human abilities).

    ***Me: I think I’ve come across SS on the web. You gotta start somewhere. So, even if the early IQ tests were based on this assumption, we have 100 years of data on the topic / refining as needed. We also have other ways to measure IQ that correlate nicely with IQ scores, and have data showing that brain processes correlate. We were still using the army alpha or Binet’s original test, that would be a problem. We’re not.

    The current “accepted” model is the CHC. I’ll link to it here and note this guy is not a race researcher (I’ve met him and he’s a very competent scientist). It’s a data driven model. The circles and arrows are not arbitrary nor based on expert opinion of what intelligence is. Instead, they are based on what analysis of the data reveal:

    http://www.iqscorner.com/2009/12/chc-theory-of-intelligence-and-its.html

    The problem with multiple intelligences is the positive manifold. If it’s a cognitive test, it’s g-loaded (scores on it will correlate with scores on other cognitive tests).

    No one’s been able to derive a measure of an “intelligence” that isn’t correlated with g. This is a big problem if you claim multiple intelligences exist. Worse, no one’s shown that their type of intelligence measures/predicts anything important once g is controlled for.

    Another way to state this “law”– within person differences on a battery of cognitive tests will always be smaller than between person differences.

    So, Gardner posits something like 7 different “intelligences” but has never (in 30 years now?) shown how these can be measured and how they are not just another way to measure g. Sternberg has 3 iq’s. He also has failed to show how to measure a non-g intelligence.

    The media eat up gardner and sternberg. Education people seem to love the idea of multiple IQs and learning styles. The data consistently show they don’t exist.

    Here’s a very recent article questioning the validity of people having different learning styles (appearing in one of the best journals in social science):

    http://www.sciencedaily.com/releases/2009/12/091216162356.htm

    If anyone’s still interested at this point, the January 2010 issue of Intelligence is out and online / open access. One can browse the abstract for each article fairly quickly to get a sense of what people in the field think is current and important regarding IQ (although browsing the contents won’t help defend against claims that it’s biased).

    But, in thinking about this, I wonder what would falsify your world views.

    If I cite data by an author; it’s completely discounted because he’s racist.

    If I cite a journal; that’s discounted because the editors are racist.

    So, I take the same author and show he has multiple pubs in journals where he is not editor, and where reputation is elite / no one would claim the journal is biased.

    That’s ignored.

    So, I cant cite anything in field as you get to dismiss it as biased.

    Even crossing into publications in non-biased journals doesn’t seem to do.

    What evidence then can I offer that you would accept as valid?

  162. #163 Barn Owl
    December 23, 2009

    Adrienne @ 154:

    Citation needed.

    To express my opinion? I don’t think so. That’s for Greg to determine, anyway – it’s his blog.

    If IQ tests are meaningless, should all murderers be executed regardless of their possible level of intelligence?

    I don’t think anyone should be executed, regardless of IQ. Unfortunately, I happen to live in the execution capital of the US, but that doesn’t mean I support the death penalty myself.

    Also, do you accept the validity of IQ tests in determining whether is someone is retarded or not? Or “gifted” or not?

    No, FWIW, I don’t. Why do we have to put people in such categories, anyway? Does meaningful and beneficial education require IQ categories and cut-offs?

  163. #164 Deen
    December 23, 2009

    If IQ tests had no value, why are they used so often?
    Why do companies use IQ tests, wouldn’t using them be discrimination?

    Those are easy questions: managers love simple metrics to base their decisions on. Even if those metrics are next to useless. Anyone who’s ever worked in a large organization can probably come up with examples.

  164. #165 Alice
    December 23, 2009

    “Why would BIG CORPORATION use X if there was something wrong with it? They would NEVER do that!”

    wow. just wow. how can this construction come from a sentient modern living human being? wow.

  165. #166 Bryan
    December 23, 2009

    Quote: Those are easy questions: managers love simple metrics to base their decisions on. Even if those metrics are next to useless. Anyone who’s ever worked in a large organization can probably come up with examples.

    ***

    Until one gets sued and has to prove to the court the job-relatedness of the test.

    10% of european firms use graphology to hire people (analyzing handwriting to determine personality). It has zero validity and showing its valid would qualify for James Randi’s million dollar prize.

    No one will sue about graphology, though, because using a stupid / invalid selection method is legal. It’s only illegal if it excludes one protected class more so than others. Graphology does not do that.

    There are many examples of inane things used by company’s to screen people; ironically IQ emerges at the other end of the spectrum (i.e., the single best predictor of job performance; but the one that creates adverse impact).

  166. #167 Kitten
    December 23, 2009

    Stephie :) I addressed my message to Greg because it’s his blog. You are the first to ever call me Kitten, I kind of like it, more people should call me that, it’s very fitting since I love cats and just animals in general.

    Greg, I never actually said what my thoughts were on IQ, you are assuming Bryan and I feel the same way. We are two different people, with different views and opinions.

    You didn’t really answer my questions and maybe that’s because you don’t have an answer. If IQ tests are crap then how would you suggest testing to see what job is most suitable for a person without costing a ton of money for the company and being time consuming, with equal results that IQ tests do predict.

    Why is a person classified as being racists if they feel IQ tests show differences? I’m just a little confused as to why it seems most everyone on here believes that to be true. I would think how a person interacts with others would show a stronger argument.

    Would I be considered a racist if I said according to the American Cancer Society more black women have breast cancer than white women? That statement has nothing at all to do with how I feel about black women and more to do with me thinking, if it’s true, why and what can be done about it. How can we move forward when people would rather claim racism then to discuss and take on problems head on?

    If there’s a problem fix it, put aside personal opinions and work together to find a mutual solution, you can’t work together if everyone is pointing a finger and calling each other names.

  167. #168 Greg Laden
    December 23, 2009

    Kitten, I don’t think IQ tests are crap. I also think using IQ test to place people in jobs is dumb.

    I will repeat, that the 70-85-105 genetic/race/iq model is crap.

    Why is a person classified as being racists if they feel IQ tests show differences?

    I don’t know. I don’t think of myself as racist, but I think IQ tests show differences.

    I also am pretty sure you are not paying attention to what I’m saying.

  168. #169 Isabel
    December 23, 2009

    “Where I think IQ tests have real value is: 1) ranking people who all take the same test at the same time in the same conditions,”

    Precisely. Otherwise, comparisons are meaningless. This is built in to the tests.

  169. #170 Stephanie Z
    December 23, 2009

    Kitten, precisely. You complained about my behavior on another blog to Greg on this one. That is what I said.

    Enjoy the new nickname, but I really can’t take much credit. Thank Tolstoy.

    And please, call me Stephanie.

  170. #171 Peter Lund
    December 23, 2009

    Adrienne, you’ll do fine in comp.sci. — at the least, it won’t be your “low” IQ that does you in ;)

    There are some basics that will make it easier:
    1) get a real OS (Linux) – because the hood is not welded shut and you have easy access to various languages and libraries. (Shame about the gdb debugger, though.)

    2) learn to program.

    3) learn the entire stack from gates to high-level languages.
    a) learn assembler
    b) learn C. If you don’t understand pointers then you don’t know C (or assembler). You also don’t understand ownership issues which is important for well-structured programs in most languages. K&R 2nd ed is highly recommended.
    c) learn what the OS does. man is your friend
    d) learn a functional programming language, preferably not Lisp. Best is if uses a Hindley-Milner type system. On the other hand, Haskell might be a bit too mind bending. ML or OCaml might be just right.

    4) be paranoid :) (= be very careful and don’t write clever code and don’t trust your coding ability too much)

    5) read Glenford J. Myers, “The Art of Testing Computer Programs”. Testing is hard and important. It also tests humility and paranoia (see above).

    6) measure. Be empirical instead of philosophical. Linux has a damn nice performance monitoring framework these days (since kernel version 2.6.31) — you might need to compile the command line tool (‘perf’) yourself, depending on your distro. Use matplotlib. Use instrumentation code to draw graphs with cairo. I helped a friend do that with his SAT solver and he got some surprises regarding its dynamic behaviour despite his having written SAT solvers for years.
    Many academic papers are marred by lousy measurements and most academics don’t know how to use measurements and graphs to get a “window into the box” of their programs.

    7) learn a bunch of tricks, such as using sentinels to mark the end of arrays so you don’t have to track their size with a counter.

    You don’t have to learn everything at these levels – you don’t have to know the opcodes by heart or know the SIMD instruction zoo. You also don’t need to know all the printf() and scanf() flags, for example.

    Recommended blogs: rjlipton.wordpress.com, hunch.net, blog.computationalcomplexity.org, 11011110.livejournal.com, pragmatictheory.googlepages.com, blogs.msdn.com/devdev (and its successor blog). If you want to see damn fine C coding and engineering, go have a look at the linux-kernel and git mailing lists.

    Recommended books: K&R, Glenford J. Myers, early editions of C.J. Date’s database book (back when it covered network databases and object databases as well + was only one volume), the Camel book (skip this if you learn Python instead), Jon Bentley’s books on programming pearls, Foley and Van Dam (if you want to learn computer graphics), one of the dragon books (for compilers), Tanenbaum’s book on networks (accept no substitute), Weinberg’s The Psychology of Computer Programming. McConnell’s Code Complete is great (except when he talks about the actual code — he is not a very good programmer). All Knuth books are great but might be too daunting if math is a problem.

  171. #172 Barn Owl
    December 23, 2009

    Greg @ 168:

    I also am pretty sure you are not paying attention to what I’m saying.

    Looks like the opinions of those of us who think that IQ tests are crap, are being projected onto you. And onto Stephanie Z. Sorry!

    LOL, am I an IQ test denialist???

    It’s amusing to me that some will insist that the score on the MCAT, a standardized test required for medical school admission, is the best predictor of later performance on the USMLE Step 1, another … standardized test.

    These self-fulfilling academic prophecies, they slay me. Bwahahahaha!

  172. #173 vonagan cheeseman
    December 23, 2009

    @Bryan:

    I have to reveal that you are a victim of internet experimentation, the new hhttp protocol (hyper hyper text transport protocol). This blog actually exists in 1969, not 2009. No one here has read any of the literature since then.

    You seem to have serious curiosity about these matters. You ought to look at Steve Hus’s blog, Steve Sailer’s blog, and the two GNXP blogs that Razib Khan maintains. At these you will find people from this century.

    Von

  173. #174 Bryan
    December 23, 2009

    So using iq tests to hire people is dumb, yet the science shows conclusively across literally 100s of studies that IQ is the single best predictor of job performance, and that using it can save / does save firms mega-dollars.

    One can even calculate exactly how much return on investment the IQ test will give by limiting hiring mistakes or not hiring good people.

    The effect is so well replicated that the american court system accepts the concept of validity generalization (essentially: stop showing us even more data that IQ is valid; we get it; you don’t need to revalidate it every time you use it).

    Greg, it seems like you reject science when it doesn’t confirm to your world view.

    You are either speaking from a position of extreme ignorance (not realizing the literature on IQ and job performance) or extreme irrationality (rejecting it because it doesn’t feel right).

    You can’t even use the “racist” card to dismiss the studies as most of them were published in journals like personnel psychology or journal of applied psychology. None of them were published by rushton or jensen.

    http://psycnet.apa.org/index.cfm?fa=buy.optionToBuy&id=1998-10661-006&CFID=5041490&CFTOKEN=44247066

    By the way, this article’s been cited 1214 times in the peer reviewed literature, so please do try to dismiss it as junk.

  174. #175 Kitten
    December 23, 2009

    Stephanie, now that is the correct way to ask someone to refer to your name in a particular way, not by calling them sexist. I have never written on any other blogs so I have No idea what you are talking about.

    I may not have been following you 100% Greg, I’m just baffled by the way people debate on here.

    In any case, may you all have a wonderful holiday, however you celebrate it :)

  175. #176 Bryan
    December 23, 2009

    Also, this study was commissioned by the department of labor; obviously racist and junk science.

    What’s the DOL know about job performance or fairness or how best to select people for hire?

  176. #177 Bryan
    December 23, 2009

    Ah, and I was wrong– it’s 1000s of studies that show the relationship, not 100s.

    At this point, if you won’t admit your ignorance or irrationality on this specific point, I think I’m done.

  177. #178 Raging Bee
    December 23, 2009

    But by citing the observation that if the races are given iq tests, a group mean difference will exist favoring whites over blacks– that makes me a racist.

    No, Bryan, that’s not why we’re starting to suspect you’re a racist. We’re starting to suspect you’re a racist because of your dishonesty. First you assert a belief, with quite a bit of certainty, that there’s a “biological” cause of IQ differences between races; then, when we point out the flaws in your arguments, you suddenly pretend you’re “agnostic” and you want to wait until more data comes in — after ignoring the enormous masses of data that’s already available but doesn’t seem to support the conclusion you’ve already decided you want to reach. When people start changing their story and talking out of both ends of their mouths like that, it usually means some kind of prejudice at work. If we’ve misread you in that respect, you have only yourself to blame, due to your inconsistency.

  178. #179 Greg Laden
    December 23, 2009

    Bryan, my personal opinion is that using IQ to hire people is dumb. I am pretty much unfamiliar with the literature on it. I do not engage very often in the corporate world, where I assume you find these hundreds of studies proving conclusively that any corporation that fails to use iq test is screwing up. I defer to you on that. You are, after all, a psychometric consultant for mainstream corporations.

    My opinion is just a personal one and I have similar opinions about the rest of corporate America, some founded on good experience and reason, some simply because corporate America disgusts me in many ways.

    Greg, it seems like you reject science when it doesn’t confirm to your world view.

    This is fairly insulting. Fuck you. Your next comment WILL be an apology.

    I’m going to ask this one more time. After your apology to me, you can anser it or you can take a hike.

    I’ll abreviate it becuase I’m tired of saying it.

    70-85-105 genes/races/IQ. WTF?

    You would do well to pay attention to the people you are compulsively making the same point to again and again and again. If I ask you to pass the salt and you hand me the pepper every time, a gain and again, I will start to think you have a problem. I might even question your IQ.

  179. #180 Stephanie Z
    December 23, 2009

    No, Kitten. The correct way to tell someone what you want to be called on a blog is to sign your posts and comments, as you’re now doing. Asking is simply the last resort when dealing with someone too dense to figure that out or to understand that what is said to one member of a marriage on the subject goes for the other member as well.

    This really isn’t that hard.

  180. #181 mk
    December 23, 2009

    “At this point, if you won’t admit your ignorance or irrationality on this specific point, I think I’m done.”

    Yikes! Irony meter just blew!!

  181. #182 Bryan
    December 24, 2009

    Greg. You have clout and legitimacy by virtue of being a “science blogger” and by your impressive academic credentials. I think you have a responsibility to your readers to not use your authority to make claims out of ignorance, or that flatly contradict (in this case) 1000s of studies.

    You obviously are not an expert in this area, stop playing one here (stop abusing the intellectual power vested to you by virtue of being a science blogger). Corporate world my ass. There’s no excuse for not knowing the IQ / job performance relationship (no excuse for any scientist claiming to have scientific knowledge in this area). It’s not a secondary issue; it’s the single biggest thing the field’s done over the last *38* years (year after year, in direct response to the supreme court’s ruling in griggs v. duke power).

    You cannot be unaware of this research and then claim that your opinion on IQ is anything more than that– an ignorant opinion. Yet, you post / link to a list of suggested readings. That implies familiarity with the literature. Could there be more things in heaven and earth here?

    I’m sure you feel you’re “fighting the good fight / have the moral high ground / are stamping out ignorance yet again”. But, you’ve committed the worst types of intellectual sins: arrogance from ignorance; refusal to consider evidence that contradicts your world view; relying on your intuitions over 1000s of peer-reviewed studies. I know your irony meter’s ringing. Perhaps use the opportunity to re-read your comments above. I deferred to genetic posts here because I am not expert in that field. I also deferred to those posts on pre-natal development for the same reason. You defer only when an undeniable ignorance is exposed. I say shame on you.

    I won’t reply to MK here, because he/she seems like an idiot. You clearly are not. That’s what scares me.

    p.s. to Von—thanks for your comments.
    p.p.s. Saved the whole thread for use a case study in my critical thinking class.

  182. #183 vonagan cheeseman
    December 24, 2009

    Senility is a terrible thing. I recommended the “Steve Hus” blog when I meant the Steve Hsu blog: http://infoproc.blogspot.com/ . The owner is a physicist, hence numerate and follows common sense.

    Von

  183. #184 Paul Crowley
    December 24, 2009

    People keep saying they’re not trying to change anyone’s mind. I don’t understand why not. I’m reading because I don’t think I know the answer on this question and I would like to.

  184. #185 ian
    December 24, 2009

    Excuse my ignorance guys but I was under the impression Rushton’s schtick was relating IQ to penis size… his way of intellectualizing his own perception of physical inadequacy.

  185. #186 Jud
    December 24, 2009

    Best blog post(s) evah! re IQ, pretty much the Final Word: http://www.cscs.umich.edu/~crshalizi/weblog/523.html

    Money “quote” is the title of the piece:

    g, a statistical myth

    g is the term used for IQ in academic studies.

    IQ tests have made me tens, maybe hundreds of thousands of dollars (in the form of scholarships, then a better start in the job market), and I am here to tell you they are as valid as those placemats they used to have in diners with puzzles for kids to solve.

    Think about the notion of IQ itself for a minute. This is supposed to be a number (or collection of numbers) that sums up your mental abilities. Let’s analogize this to physical abilities for a moment. Let’s make up a factor that is supposed to sum up your physical abilities and call it “athleticism.” Now, is Mary Lou Retton, Michael Jordan, Usain Bolt, Tiger Woods or the Russian Olympic champion wrestler Karelin more “athletic”? Obviously a useless question, since the single factor “athleticism” can’t cope with the variety of human physical abilities illustrated by even this small sample of 5 people.

    Do you think that human mental capabilities might be as multifarious as, perhaps even more varied than, our physical capabilities? Then as obvious as it is in the example above that “athleticism” would be an arbitrary, useless concept, it should be just as or even more obvious that IQ is also useless, simply an arbitrary number or collection of numbers that follow certain statistical laws because – well, read the blog post above, and Cosma Shalizi, who forgets before breakfast every day more knowledge of statistical laws than I will ever learn, will explain it nicely.

  186. #187 vonagan cheeseman
    December 24, 2009

    @Jud

    Your post about athleticism is quite correct, and the contrast between the search for “athleticism” and search for “intelligence” is pretty interesting, one of the more interesting products of the biometricians at the turn of the century (nineteenth to twentieth century).

    Their data showed very clearly that there was no unitary athletic ability: some kids were strong, some had endurance, some had balance, and these were not correlated. But grades did not have this pattern at all: kids with good (musical) pitch also had good grades in math and Latin, and so on. This empirical finding led to the notion of intelligence as a general ability, independently of whatever the French like Binet were doing.

    This finding makes no apparent biological sense, e.g. why should not someone who is a great writer or fast talker not suffer some deficit in math? But the data show that folks good at language are also _good_ at math, not bad at math.

    There is no support at all in any data that your suggestion that IQ is like athleticism is true in any sense at all. It is also true that no one has a decent model to explain this finding.

    Von

  187. #188 mk
    December 24, 2009

    “I won’t reply to MK here, because he/she seems like an idiot.”

    Wow…. you just figured that out? Man, you’re slow.

    Anyway… Just for fun, since you conveniently ignored it, I’m reposting the last comment by “raging bee.” It’s so worth it.

    [my emphasis added]

    “No, Bryan, that’s not why we’re starting to suspect you’re a racist. We’re starting to suspect you’re a racist because of your dishonesty. First you assert a belief, with quite a bit of certainty, that there’s a “biological” cause of IQ differences between races; then, when we point out the flaws in your arguments, you suddenly pretend you’re “agnostic” and you want to wait until more data comes in — after ignoring the enormous masses of data that’s already available but doesn’t seem to support the conclusion you’ve already decided you want to reach. When people start changing their story and talking out of both ends of their mouths like that, it usually means some kind of prejudice at work. If we’ve misread you in that respect, you have only yourself to blame, due to your inconsistency.”

    And now, on top of all that, you’ve stooped to gratuitous insults towards the host of this blog. So… not only have you shown yourself to be dishonest, rude, stubborn and possibly a white supremacist, but–from this idiot’s perspective–you’re also a real dick-head.

  188. #189 Raging Bee
    December 24, 2009

    mk: First, I was insulting Bryan, not the host of this blog. Second, the insult was not gratuitous — it was based on my observation of Bryan’s behavior, which I described in support of the insult. Either you know this, and are pretending you don’t, or you simply didn’t read the very text you had copied and pasted. Either way, you’re acting like an idiot.

    Bryan: attacking the host of this blog and questioning his expertise, AFTER ignoring the substance of nearly every comment exposing the flaws in your reasoning, really doesn’t help your credibility, especially since the original post clearly acknowledged and addressed a wider range of observed facts than your “I believe it’s biological” schtick ever did. Greg may not be a pre-eminent expert in this field, but he has, at the very least, acknowledged that there’s a huge and complex web of factors affecting intelligence (all together now: DUH!), while you have doggedly clung to a shamefully simpleminded — and, yes, racist — “explanation” without regard to obvious and observable human experience. Pretending you know more doesn’t help when you’ve already proven you can’t handle what we know.

  189. #190 Raging Bee
    December 24, 2009

    OOPS, I seem to have totally misinterpreted the thrust and meaning of mk’s comment, and needlessly insulted him as a result. It turns out his remarks were directed at Bryan, not at me, and I mis-reacted in haste to a slight bit of ambiguity in mk’s wording. Please disregard the part of my last comment that was in response to mk, and accept my humble and decidedly red-faced apologies. “My bad” is a bit of an understatement here.

    Where’s that white IQ advantage when I really need it?

  190. #191 Stephanie Z
    December 24, 2009

    Bryan, I have not ignored the information about IQ correlating to job “performance,” but you have ignored my discussion of it. As I pointed out on Quiche Moraine, in the comments on my reading list (mine, not Greg’s, and why would you credit my work to a guy?), this is one of the more problematic aspects of the creation of IQ tests.

    The American workplace is widely understood to have a pervasive bias against minorities. This is why the EEOC exists, after all, and there is plenty of research documenting both these biases and the ways they are perpetuated. To require that tests and test items be predictive of success in the workplace is to incorporate the biases of the workplace in the testing. The way that IQ tests are validated, a test that better mirrors those biases is considered a better test.

    Just so we’re clear: This is bad.

  191. #192 Jason Thibeault
    December 24, 2009

    Raging Bee: mk was reposting and adding to your comment. He was definitely attacking Bryan on that.

    And by the way, I am enjoying this thread immensely.

  192. #193 Jason Thibeault
    December 24, 2009

    Bee @190: apparently your white IQ advantage is in the same place as mine, as I appear to be incapable of remembering to refresh a thread before commenting.

    Stephanie@191: I’ve never had an IQ test as any sort of deciding factor for any of my jobs — does that happen often in the States?

  193. #194 Raging Bee
    December 24, 2009

    Jason: In my own experience, IQ has NEVER been a major factor in hiring decisions. This applies to everyone else I’ve talked to about job-hunting-related matters. Employers use previous work experience (and references) first and foremost, security clearance a close second (if not first), college grades and other credentials a distant third (more significant for people who just graduated, of course), and miscellaneous other factors as tie-breakers. IQ? Fuggeddaboutit. If an employer needs to test your intelligence, they’ll be using their own test to measure the particular skills you need for their particular kind of work. They don’t have time for vague general numbers like IQ.

  194. #195 Greg Laden
    December 24, 2009

    I was to one degree or another in charge of employing people in jobs that required smarts (environmental assessment consultants, teachers, lab technicians, scientists, etc) from about 1978 to about two years ago. IQ never came into play. I would not be surprised if IQ correlated with certain aspects of performance, but there were key features that DID correlate with performance that I’m pretty sure would be uncorrelated with IQ.

    I’ve also been on grant review committees and admission committees for both graduate and undergraduate programs a lot and IQ was never a measure that was available. GRE’s were. GRE’s for graduate students don’t predict what is important for their performance.

    I assume that Bryan’s IQ use is confined to the corporate world. In the world of hiring MBAs and such, they probably love things like IQ and even where they work only moderately well, will continue to like them.

    But in fact I’ll bet they work well. IQs are not unbiased culture-free tests (despite protestations to the contrary). And, it would seem that the money is behind their use in the corporate world. So to make the tests effective in that world, of course they are honed and tuned to work better (isnt’ that the whole point of Bryans consultancy?) So sure, in that world, this may work pretty well.

  195. #196 daedalus2u
    December 24, 2009

    Jud (#186) has an excellent link. I don’t know the literature well enough to characterize it as “the best”, but it is very good.

    EB Wilson pointed out the fatal problem in 1928. Trying to get a unitary “g” is equivalent to solving k equations for k+1 unknowns. It is indeterminate. Even if g were a real thing, testing would be unable to determine it.

    A more fundamental problem, not addressed by Wilson (and I presume the others that followed), is that the way that g is calculated is by assuming results on specific IQ tests are a linear combination of g with different weighting factors.

    What in physiology is linear? Absolutely nothing is linear, except in a narrow range, a range that is very narrow compared to the normal physiological range. Assuming linear weighting factors in a neural network (as in Perceptrons) shows that linear neural networks can’t do very much. What that result (that linear neural networks can’t do much) shows is that natural neural networks must be non-linear (as measurements show them to be) because they have capabilities not possible with linear networks.

    We know that natural neural networks self-regulate in the critical percolation threshold, a true critical point where the properties of the network are exponential with connectivity (a true exponent). Exponential behavior is about as non-linear as you can get.

    Once the weighting factors are allowed to be non-linear (which we know they are), then the indeterminacy becomes of much higher order.

  196. #197 Adrienne
    December 24, 2009

    Thank you to Peter Lund for all of his suggestions re: CS! I really appreciate those.

  197. #198 mk
    December 24, 2009

    No problem folks (raging bee and Jason T)… I misread and post hastily and generally make a fool out of myself here on a pretty regular basis. (just ask Greg and Stephanie!) Everyone should do it occasionally!

    Seriously though, all of you have been helpful in more ways than you’ll know. Muchas gracias!

  198. #199 Oran Kelley
    December 24, 2009

    I am very suspicious of the slippage between IQ as measure of “intelligence” and IQ as predictor of school or work performance. I think these two claims ought to be kept strictly segregated, and Bryan tends to totally ignore it.

    One of the dangers with school and work performance is that there are a huge number of factors that enter into them, many of them uncontrollable, hard to characterize, determine & enumerate.

    Bryan writes as if “good job performance” were a very simple thing that we all agree is the goal. But “good job performance” is actually one of the things under scrutiny.

    To use the example of the military is actually pretty interesting–they clearly think the tests tell them something or they wouldn’t bother. But on the other hand the military has also pursued a fairly aggressive affirmative action policy in promotion and assignment as well. The organization though has pretty good job performance on the whole, and if you think about it the racial composition of its leadership is part of that success–the fact that largely minority soldiers can see other minorities in positions of power improves the performance of the whole, and race–being black or latino–may improve individual job performance directly in some situations (e.g. your Latino underlings want you to do well, or your superiors want to have a successful young Latino captain they’ve helped bring to the fore) because job performance is essentially a subjective measure–it is a sum of all the inputs everyone involved brings to the table–including racism, paranoia, group identity issues, etc, etc. Job performance is a political issue, not an objective measurement.

    The fact that IQ correlates well to job performance, to me, is an indication that it is also an amalgam encompassing many or all of those same cultural, social and political factors.

    Factors that we can work to alter if we choose rather than enshrining them in pseudo-objectivity.

  199. #200 Yawn/Tooters of JPMorgan Chase & Co.
    December 24, 2009

    The influence of SES pales in comparison to race on IQ.

    Whites in poverty score as high or higher on the SAT as the wealthiest blacks.

    Interracially adopted (to rich white parents) black children also grow up to have the same IQ’s (about 85) as their impovershed brethren in the ghetto, according to the Minnesota adoption study.

    The only answer besides the obvious, simple explanation of genetics, is “IQ tests are racist!” or “The loving adoptive parents are really closet racists!” LOL
    It is also laughable to think that every single human group has the exact same distribution of whatever the genetic basis (there is a genetic basis, as there is for every trait) for intelligence is. Race is biologically real, not a social construct, and we are not all the same.

    Funny how not many people have a problem with attributing black americans success in athletics to genetics. But intelligence is a taboo trait, apparently.

  200. #201 Oran Kelley
    December 24, 2009

    SES is one factor–it doesn’t mean “all possible cultural or social factors.” You do realize that, right?

  201. #202 Greg Laden
    December 24, 2009

    Oran: “slippage” ….

    that is the whole problem. I have yet to have any of the IQers answer any of my key questions. And, my question is about slippage. I said last time I brought the question up that I would not do so again. What I will do is terminate certain parts of this conversation unless they are addressed, because slippage is the key issue.

  202. #203 Stephanie Z
    December 24, 2009

    Tooters, for fuck’s sake, take some basic classes in statistical analysis, would you?

    IQ tests being racist is, in fact, one of the things we’ve been talking about. See comment 191 for an example of why. And your comment about parents is laughable in two ways. Parents are hardly isolated from the kinds of claims we’re seeing right here (“You must be without current or future progeny to view this site. Click here to verify.”), and expectations regarding intelligence decidedly affect the treatment of children. Also, parents are nothing like the only people kids interact with.

    As for race being biologically real, I refer you to the link in comment 147 as a start. You want to talk about this instead of it being taboo–try to keep up when we do.

  203. #204 Yawn/Tooters of JPMorgan Chase & Co.
    December 24, 2009

    No such thing as race?

    Wake me up when white sprinters are well-represented in the 100-meter dash. There must be loads of institutional racism in the Olympics to discriminate against my people so.

    Wake me up when AA’s in the ghetto produce the number of physicists that poor urban Jews did.

    It will never happen.

    The racists. be. everywhere.

  204. #205 lylebot
    December 24, 2009

    I think around 125-130? I’m wondering if I could survive a master’s program in computer science.

    You’ve got to be kidding. As a CS professor, I can assure you that we give Masters degrees to plenty of people that have IQs lower than 125. Frankly I’m not sure my own IQ is much higher than 125 and I finished a PhD in the subject. If you’re struggling, it’s not because of your IQ.

    I want to second something daedalus2u said way upthread: why do we consider “intellectually demanding” activities to be those than computers can be programmed to do easily? Since when does being able to think like a computer mean you’re smart? Especially when every single human being on earth solves extremely hard computational problems every single day of their lives.

  205. #206 Raging Bee
    December 24, 2009

    Wake me up when…

    Here we have Yawn/Tooters pretty much admitting he’s not even conscious, let alone seeking out or processing new information. Just like all those other bigots pretending to be the smartest guys in the room.

    There’s really no use arguing with a guy who’s already admitted he’s not awake.

    And if, by “poor urban Jews,” Toots means the families of Einstein, Oppenheimer, etc., those guys didn’t grow up in poor ghettoes; they had pretty decent educational opportunities that “AA’s in the ghetto” don’t normally get.

    I hope Tooters doesn’t wear his white sheet to Hooters…

  206. #207 Raging Bee
    December 24, 2009

    Randomly skimming the comments to the article cited in #147 above, I stumbled on this gem:

    Whenever I run into a discussion about race, I always ask: “When did the Irish become white?”

    Any comments, Bryan? Tooters from Hooters?

  207. #208 Sarah Connor
    December 24, 2009

    If you believe that our thoughts and behaviors arise from the physical structure and physiological makeup of our brain, then you have to believe that the genetic program that creates our brain must play a significant role in determining how it operates, “intelligence” included.

    AI Systems That Can Pass IQ Tests

  208. #209 Jud
    December 24, 2009

    Von @197 writes:

    This finding makes no apparent biological sense, e.g. why should not someone who is a great writer or fast talker not suffer some deficit in math? But the data show that folks good at language are also _good_ at math, not bad at math.

    So someone who can learn math in a classroom setting and do well on classroom math tests can also learn language in a classroom setting and do well on classroom language tests. Jeez, I guess we’ve about exhausted the gamut of human mental capacities, haven’t we?

    What about the folks you know who always seem to be politically canny, vs. those who might be quite bright but are politically inept? (I can certainly think of good examples of each where I work. For examples who might be familiar to some of you, I’d select Ronald Reagan for someone who wasn’t thought of as surpassingly intelligent in the academic sense, but who rose to the presidency of the Screen Actors Guild, then became Governor of California, then a hugely popular President of the U.S.; and Lubos Motl, a brilliant young physicist, who, even among other prodigal physics geniuses, managed to make himself so politically unpopular that his continued employment at Harvard became practically impossible.)

    Of course there are the extremes, such as the recently deceased Kim Peek (a/k/a the “Rain Man”), who could instantly tell you on what day of the week centuries-old events took place and possessed various other savant-type capabilities, while we may all be aware of quite brilliant people in various fields who can’t tell you what day of the week it is today.

    There are folks who have excellent senses of direction, and folks who don’t. I have friends who didn’t graduate from high school who have so much of the instinct for the right decision we call “common sense” that I’d willingly trust my life to them, and others with graduate degrees who leave me dumbfounded with their naivete. There is my manager at work, who cannot write a grammatical and properly capitalized paragraph to save her life, but who knows more than any other two people in the company about provisions of the U.S. Social Security Act so densely worded that lawyers and judges have publicly complained of their impenetrability. And yes, there are plenty of people I know who are terrific at language but awful at math, or vice versa. (Interesting that studies have found female students’ math performance increases in the absence of males – anyone care to explain *that* on the basis of some sort of inherited general intelligence factor?)

    So no, it isn’t surprising at all to me that what we think of as “intelligence tests” have self-consistent results. (The distillation of a common general factor from the results of a series of individual tests is unavoidable as a matter of statistical laws, see the link I provided at #186.) All such self-consistency shows is the inadequacy and arbitrariness of the tests. To go back to my “athleticism” example, when you get a scale that allows you to rank the “athleticism” of Mary Lou Retton, Michael Jordan, Usain Bolt, Tiger Woods and Karelin using a single number for each, what you know for certain about that scale is that it is so vague and meaningless it allows you to obliterate all the very real differences in physical capacities between these people. The same seems to me to be self-evidently true about the preposterous idea that one can reliably evaluate and rank human mental capabilities in terms of a single number.

  209. #210 orin
    December 24, 2009

    The discussion here has been ignoring the large number of findings that have appeared in the scientific literature over the past 30 years or so. While it is true that some of the correlations between IQ and other factors do not demonstrate a genetic basis, when taken alone, the evidence of many such observations is that they all point to a genetic basis. Some of the correlations cannot be rationally explained by non-genetic mechanisms. For example, inbreeding depression is entirely a genetic effect and has been measured with a large N. That genetic depression loads (vector loading on the Wechsler) exactly the same way for Japanese and American blacks.

    Regression to the mean is observed for all population groups and shows the predicted centering of the distribution of IQ in offspring. This shows, for example that if two groups with the same mean are selected, where the groups are from breeding groups that have different means, the children of each group will regress to different points, namely to the points that are the means for their genetic groups.

    The environment acts only at the non-shared level for adults. No family factors can be found in adults. All of the correlation between related adults is genetic.

    The people here apparently think that the only way to measure heritability is by looking at twins reared apart. This is not correct. There are four methods which are independent and which each show narrow sense heritability at or above 80%. The methods are: MZA correlations; Falconer’s Formula; path analysis; and subtraction of the environmental variance fraction from one. The latter method produces the highest heritability.

    When blacks are adopted by families with higher IQs, the children show an initial gain, relative to their biological peers, but that gain is from the shared environment and that component vanishes quickly after age 12. As adults the blacks have the same IQs as their biological peers and their IQs show no correlation to their adopted siblings. But when East Asians have been reared by white families, the same thing happens, only the East Asians end up with IQs that are higher than those of their adoptive parents.

    Not one social factor has been found that will alter g in any way (other than for a few hours, which can happen by simply being drunk). Of the environmental factors that have been identified, all are detrimental to g. None boost intelligence.

    The environmental argument also fails to explain why heritability increases over time. If the environment is acting on intelligence, the opposite must happen.

    Intelligence is ultimately the sum of a number of biological factors, such as neuron density, cortex thickness, neural pruning efficiency, nerve conduction velocity, neuron count, degree of myelination, and a few structural factors that are opposite for the sexes. IQ measurements (using Fagan’s method) for toddlers are predictive of their later intelligence and school grades. Brain measurements from longitudinal imaging studies show that brains vary in structure from infancy on and follow developmental paths that are different as a function of g.

  210. #211 Raging Bee
    December 24, 2009

    The discussion here has been ignoring the large number of findings that have appeared in the scientific literature over the past 30 years or so…

    And you, orin, have completely failed to cite even ONE of this “large number of findings.”

    The environmental argument also fails to explain why heritability increases over time. If the environment is acting on intelligence, the opposite must happen.

    How does “heritability” increase over time?

    Intelligence is ultimately the sum of a number of biological factors, such as neuron density, cortex thickness, neural pruning efficiency, nerve conduction velocity, neuron count, degree of myelination, and a few structural factors that are opposite for the sexes.

    Is there any objective, verifiable evidence that any of these factors vary significantly from one race to another? Again, your lack of even ONE citation does not inspire confidence.

  211. #212 orin
    December 24, 2009

    daedalus wrote:

    “A more fundamental problem, not addressed by Wilson (and I presume the others that followed), is that the way that g is calculated is by assuming results on specific IQ tests are a linear combination of g with different weighting factors.”

    I dispute this comment. There is no linear assumption required. Various methods are used to extract g, although hierarchical factor analysis has been the most used in the past. Papers today ofter cite a bifactoral extraction in addition to the hierarchical result. More recently, serious research has moved away from single IQ tests towards a battery of tests that are used so that structural equation modeling can determine g at the individual level. Previously, the most common way of estimating individual g was to simply use the Raven’s score.

  212. #213 orin
    December 24, 2009

    Raging – this one’s for you:

    1) IQ test scores have been shown to predict grade point averages for all races. These projections are slightly biased in favor of blacks (they over-predict black grades).
    2) The method of correlated vectors shows that race differences in test results accounted for by g differences. The more g loaded the test, the lower the greater is the B-W difference.
    3) Response time measurements show exactly the same between group differences as are seen in IQ test scores.
    4) Inspection time differences show exactly the same between group differences as are seen in IQ test scores.
    5) Measures of brain size and proxies for brain size show the same orders of difference between the major races. These differences exist from birth through adulthood.
    6) SES has been shown to be largely the product of g, with a smaller factor that relates to paternal SES (this in turn is a genetic function). Siblings reared together statistically reach adult SES levels that are in proportion to their relative IQs.
    7) Global data sets show hybrid groups always having mean IQs that lie between the two source groups. These hybrids reach mean SES levels that are also intermediate to the source groups. In the case of blacks and whites, the admixture contributes +0.2 IQ points (for blacks) for each percent of European admixture. This must be added to IQ 80, which is presumed to be the mean for admixture zero. This equation has been shown to accurately predict the regional differences in US black IQ test scores.
    8) The B-W difference has been shown to correlate at r = -.70 with the environmental loading of tests. That means more loading causes a lower difference.
    9) Genetic variance has been shown (McGue & Bouchard) to increase rapidly from ages 4-6 to ages 6-12 and again from ages 16-20 on. The variance of the shared environment is a mirror image of this (it declines to zero). The variance of the non-shared environment declines over the first range (per above) then remains relatively constant.
    10) Head size has been shown to be a robust proxy for brain size. It varies by race from birth and in proportion to the IQ differences between the races.
    11) The B-W gap exists at age 3-1/2 onward. This is way before school and before other environmental factors have time to operate.
    12) The transracial adoption studies showed that family environment has no effect at all on adult IQ. All races develop via genetic patterns.
    13) Regression studies have shown that US blacks have a regression point of IQ 85 and US whites (European) of 100.
    14) Cultural achievements of each population group are in proportion to IQ.
    15) Intervention programs have failed to produce lasting gains in IQ and have not shown any gains in g. Children who have been subjected to these programs reach adulthood with IQs that are the same as their peers who have not been through intervention. The reported gains have most likely been the result of teaching to the test.
    16) Recent work (this year) has shown that the B-W gap cannot be explained by stereotype threat (a favorite excuse for those who claim that all races are equally intelligent). This idea was lame from the start, since it cannot even be stated in a way that explains the higher IQs of Ashkenazi Jews and Asians.
    17) There has been no narrowing of the B-W gap over at least the past half century, despite great improvements in the environments of blacks.
    18) The highest SES blacks have mean IQs that are below SES-1 for whites.
    19) The B-W gap is largest at the highest SES level and lowest at the lowest SES level.
    20) There are no nations in which black achievement, intelligence, or SES has exceeded East Asians, Europeans, or Ashkenazi Jews. This applies throughout Africa on a within-nation basis.
    21) The B-W gap is greatest on the more heritable subtests and lowest on the least heritable subtests (the Wechsler is usually referenced).
    22) Mean B-W-East Asian IQ differences are paralleled by a race-behavior matrix of 60 life-history traits.
    23) The evolutionary explanation of racial differences, based on winter temperatures is strongly supported by correlations with latitude and both high and low mean winter temperatures.
    24) Related to 23 – skin pigmentation on a national basis correlates strongly with mean national IQ.
    25) Mean national IQ has accurately predicted international science and math scores with correlations that approach 1.0.
    26) Inbreeding depression is genetic and affects intelligence of a single race in the same way that black intelligence is shown to be lower than white intelligence (per my prior comment).

  213. #214 Scotlyn
    December 24, 2009

    Jud, thanks for the link to Three-toed Sloth’s excellent treatise on statistics relevant to the subject of this thread. I intend to study it, and learn something useful. But I think the “money post” in relation to where this thread has gotten to around now is this one!

    Happy X (fill-in-your-preference-here) Mas, everyone.

  214. #215 daedalus2u
    December 24, 2009

    orin, factor analysis assumes a linear combination.

    http://en.wikipedia.org/wiki/Factor_analysis

    If you have an example of a non-linear factor analysis applied to g, or IQ, or to any (supposed) measure of intelligence, I would like to see a citation to it.

    As far as Raven’s go, look at the reference in #29. When Raven’s gives a number that is different by 70 percentile points from the Weschler, how can they be measuring the same thing?

    If the tests only “work” on a narrow range of individuals, by what basis are you using it to extrapolate outside that narrow range of individuals? How can the reliability of the test be checked?

  215. #216 daedalus2u
    December 24, 2009

    Orin, your statements about inbreeding and intelligence are quite curious. Perhaps you are unaware that the greatest genetic diversity is in Africa?

    http://en.wikipedia.org/wiki/Human_genetic_variation

    Even in Africa, the greatest genetic diversity is in Sub-Saharan Africa.

  216. #217 sharky
    December 24, 2009

    Discussions about IQ always amuse me, because we have no way of knowing if there’s even one way to be smart–I have extremely high verbal skill and extremely poor mathematical skill, and logic puzzles pain me. But I’ve found myself spotting logical flaws when talking with people who have more scientific or mathematical aptitude than I do. I’m guessing that somehow, I compensate for my limited mathematical ability with another part of my intelligence. If that’s true, though, trying to test for intelligence is like trying to test for a certain shade of color when everyone’s mixing their own paints.

    Intelligence can’t even be measured by discrete intervals. Say the average first-grader tends to be at one point in the scale, and people whose functioning is so limited they can’t tie their shoes are a little under halfway between them and 0. Does that mean those kids are twice as smart as shoe-tying? (Does it make us smarter to have worked that pretty chart out?)

  217. #218 Raging Bee
    December 25, 2009

    orin: I asked you for citations of whatever studies or publications supported any of your assertions, and you have still provided none.

    Oh, and what about mixed-race people? Where do they fit into your picture?

  218. #219 gcochran
    December 25, 2009

    daedalus2u:

    Inbreeding refers to an unusually high degree of alleles identical by descent – for example, if your parents were cousins, about 6% of your genes would have two identical alleles. Everyone carries some deleterious mutations, and many of them are recessive – that is, the negative effects primary show up in homozygotes, those with two copies.
    If your parents are unusually closely related, you don’t (on average) have more bad alleles, but you are more likely to have _pairs_ of bad alleles, and that can be disastrous.

    This doesn’t really have anything to do with the overall level of genetic diversity of the population your parents are drawn from, at least not at the continental level. It does matter if your parents come from a small community that already practices a lot of close marriages – in that case they may share more alleles that you would think, more like uncle/niece than 1st cousins. And of course, some populations have high frequencies of particular mutations that aid heterozygotes (carriers) while harming homozygotes: most famous example is sickle-cell trait, but true also of a number of other malaria-defense mutations such as the thalassemias, also cystic fibrosis, connexin-26 deafness, etc.

    And inbreeding depresses IQ, on average: by a few points, in the case of first-cousin marriages. There are countries in which half the population or more marries a first cousin, which is unfortunate.

  219. #220 Azkyroth
    December 25, 2009

    I see IQ as being more core / central / pure than the depth of knowledge one has acquired by exposure to culture and environment.

    Why?

  220. #221 orin
    December 25, 2009

    daed: “Orin, your statements about inbreeding and intelligence are quite curious. Perhaps you are unaware that the greatest genetic diversity is in Africa?”
    This is common knowledge. How do you think it relates to this discussion? Are you attempting to extrapolate something from Africa that is explained by inbreeding depression? The point of studying inbreeding depression is that is it known to act genetically. It has no environmental path, yet it causes decreased intelligence. The best paper that I have read on this subject is M.A. Woodley, Inbreeding depression and IQ in a study of 72 countries, Intelligence 37 (2009), pp. 268–276. Woodley reported a negative correlation of r = – .62 (P < .01) between national IQs and consanguinity. The only other study to compare nations with respect to inbreeding depression is Saadat, 2008 M. Saadat, Consanguinity and national IQ scores, Journal of Epidemiology and Community Health 62 (2008), pp. 566–567.
    From Woodley, the % consanguineous marriages is above 25% in these nations: Kuwait, Yemen, Afghanistan, Iran, Jordan, Pakistan, Saudi Arabia, UAE, Bahrain, Oman, Tunisia, India, Lebanon, Egypt, Qatar, Tanzania, Sudan, Nigeria, Burkina Faso, Guinea, Kyrgyzstan, Tajikistan, & Iraq.

    Sharky: “Intelligence can’t even be measured by discrete intervals. Say the average first-grader tends to be at one point in the scale, and people whose functioning is so limited they can’t tie their shoes are a little under halfway between them and 0. Does that mean those kids are twice as smart as shoe-tying?”
    You appear to be unfamiliar with scales. Test items (any test, including a high school quiz) produce an ordinal scale. That happens for intelligence tests too, but they are force fitted to a Gaussian distribution. This causes the resulting IQ scores to an interval scale.
    Conventional IQ tests are not ratio scales, so there is no way to say that a score of 88 is 10% more intelligence than a score of 80. When intelligence is measured from biological parameters (RT, IT, volume, electroencephalography variables, and MRI dimensions) then the scales are ratio scales.

    Raging: “I asked you for citations of whatever studies or publications supported any of your assertions, and you have still provided none.”
    I have not seen that referenced material has been a major part of this discussion. How many references have you posted here? The answer is zero. If you have a specific point of inquiry, state it and I will provide a reference. Meanwhile, you can find most of the answers in these:
    Jensen, A. R. (1998). The g factor: The science of mental ability. Westport, CT: Praeger.
    Lynn, Richard (2006). Race Differences in Intelligence: An Evolutionary Analysis, Washington Summit Publishers, Georgia.
    Lynn, R. (2008). The Global Bell Curve: Race, IQ, and Inequality Worldwide. Augusta, GA: Washington Summit Publishers.
    H. Nyborg, Editor, The Scientific Study of General Intelligence: a Tribute to Arthur R. Jensen, Pergamon, Oxford (2003).

    The rest are addressed in the journal INTELLIGENCE, the only journal that is dedicated to the study of human intelligence. There are, of course, a few outstanding papers in other journals, such as Personality and Individual Differences. Given the subject at hand, the single most pertinent paper is this: Rushton, J.P. and Jensen, A.R. (2005). Thirty Years of Research on Race Differences in Cognitive Ability. Psychology, Public Policy, and Law, Vol. 11, No. 2, 235-294.
    Raging:
    “Oh, and what about mixed-race people? Where do they fit into your picture?”
    I have addressed this. Search for the word “hybrid.” If you want to understand hybrids (clines), please read the two books by Lynn that I cited above.

  221. #222 Greg Laden
    December 25, 2009

    Brian, I need you to explain exactly what you mean when you say “I think it is biological” … focusing your definition on biological. I’m thinking that by “biological” you don’t mean “Genetic” but it is not clear. THen I need you to explain what is biological about mental (respnose/neural firing) speed that is not biological about taking a test. I don’t get that distinction.

    The link between “menal rotation” (the first of these speed tests) and IQ/g has been established for quite some time and is strong. It is a very strong association. Probably measuring the same thing at more than one level.,

    I’m glad to see that you eschew the Rushton model.

  222. #223 orin
    December 25, 2009

    Laden:
    Variation in IQ across groups in a single society (like in the US) (which is not the same as a single culture) is known to be primarily caused by SES and home environment, and is indicated by such things as parents’ educational level.

    orin- Your comment is incorrect. IQ is a cause of SES to an overwhelmingly greater extent than SES is in any way causative of IQ. Parental education is one of the factors that is scored in scoring the SES level of individuals. Educational attainment correlates so closely with IQ that it acts as a pretty good proxy. It happens, however, after IQ has become stable. Education can only affect IQ measurement by reducing the g loading of the test used. This is equivalent to adding measurement error. The degree to which education has any bearing on an IQ test depends on the structure of the test. Measures of crystallized intelligence, for example, relate to scholastic test items. But, it has been shown (this year) that Gc is more heritable than Gf. It turns out that in some tests, Gc is more g loaded than Gf and in some tests the opposite happens. This has been discussed at length by Bouchard and Johnson.

    Laden:
    Educational levels of Americans have been going up for a hundred years. So has IQ. IQ can jump up in a generation if one generation is educated and changes home environment and SES etc., and thereafter those offspring and grand offspring have higher IQ’s.

    orin- The IQ gains that have been seen globally have, for the most part, been shown to have little or no g loading, and as such are hollow with respect to intelligence. Home environment has no influence on IQ. None. Zero. Intelligence is primarily determined by genetics; no aspect of the social environment (shared environment, family) affects IQ in adults.

    Laden:
    The next argument in favor of the genetic inheritance of intelligence is often to link IQ to head size or brain size. However, much of the data related to this research is very made up or cooked, the causal arrow is problematic.

    orin- The data on brain size is massive. The reason that head size is important is that it is a reliable proxy for brain volume. Although the correlation between head size and IQ is low (about .20), it is very robust. It is always found and the correlation coefficient does not vary significantly. For a detailed demonstration of the use of skull measurements to determine probable range of IQ, see Ian Deary’s paper on the study of the skull of Robert Bruce.

    Brain volume can be measured using structural MRI in living persons. The correlations found range from .33 to .40. For the past six years, it has been known that higher correlations exist by summing the volumes of the Brodmann Areas that are associated with cognition. As of 2009, further refinement has been possible by modeling cortical thickness and cortex surface area. When combined the various MRI data correlate at about .70 with IQ. Your comment about data being crooked exposes your profound ignorance of this topic.

    Laden:
    Also, a third or fourth level factor in IQ is diet, which may affect brain size. Separately, a primary factor in skull shape and bone thickness is also diet (though in totally unrelated ways) which in turn is ethnic/regional…

    orin- Diet may indeed affect brain size, skull size, and intelligence, but it does not cause the correlations to vanish. So far, the only dietary factors that have been shown to affect intelligence are shortages of iron, folate, and iodine, all of which lower intelligence. None of these factors are found in industrialized nations.

    Laden:
    The final argument in favor of the inheritance of IQ via genes passed on from parent to offspring is usually to cite the twins separated at birth studies. These studies, however, simply do not show this. These twins are not separated at birth in the way most people think they are Usually, the twins knew each other as they grew up, and/or knew commonly held family members.

    orin- Your comment requires support by a valid reference. You won’t support it because you are wrong. Separations of MZ twins have taken place at various ages, but the majority of the data is based on very early (infancy) separation cases. However, there was a paper this year that examined the separation dates (time after birth) and showed that there was no effect on the data at all.

    Laden:
    There may be a small component of intelligence that is inherited, but it seems to be swamped by other factors.

    orin- It does not seem so. You are convincing yourself that you understand something that you have not bothered to study. Only about 18% of the total variance in intelligence is accounted for by the sum of the environmental factors and measurement error. No social factors affect adult intelligence. No environmental factors boost intelligence permanently (more than the time of drug action).

  223. #224 Greg Laden
    December 25, 2009

    The IQ gains that have been seen globally have, for the most part, been shown to have little or no g loading, and as such are hollow with respect to intelligence.

    Partly true, partly not true. But to the extent that it is true, it is inappropriate to keep using the older data, would you not agree?

    I overstated/underspecified regarding SES. SES is a factor in determining IQ. The more vague but still powerful effector of Home Environment explains most of the “black white” iq difference.

    You are convincing yourself that you understand something that you have not bothered to study

    Actually, I’m pretty convinced that there is a tortured logic using oft cherry picked data and some huge leaps and flaming winged monkey distractions from contrary evidence, cloaked in a recently popular but no longer valid or interesting counter PC dressing desgined specifically to advance a rather hateful racist agenda.

    Everything you’ve provided us with is secondary, derivitive, from known racist sources, and that is assuming I know where your information is coming from because it is not directly cited.

    In other words you are engaged in an predictable, rather boring, and obnoxious bout of mental masturbation.

    Just answer me one question: Why?

  224. #225 Elaine
    December 25, 2009

    “So far, the only dietary factors that have been shown to affect intelligence are shortages of iron, folate, and iodine, all of which lower intelligence. None of these factors are found in industrialized nations.” -orin

    That is simply untrue.

  225. #226 Le Mur
    December 25, 2009

    Greg said: “I am pretty much unfamiliar with the literature on it.”

    That’s obvious.

  226. #227 Greg Laden
    December 25, 2009

    The low class style of this racist drek is sometimes astonishing.

    Just to be clear, I did say that I am pretty much unfamiliar with the literature on using IQ to test for job performance in the corporate world. Le Mur is pulling a typical stunt in his particular comment.

  227. #228 sharky
    December 25, 2009

    Orin: My point is that the test gives you a relative value to the other people who tested; however, that tells you nothing about those who tested far lower or far higher.

    And it isn’t even useful when compared against itself, since the things that are being tested don’t compare or scale.

  228. #229 Stephanie Z
    December 25, 2009

    However, Le Mur, plenty of other people in this thread aren’t. Funny how people would prefer to argue with Greg.

  229. #230 Greg Laden
    December 25, 2009

    Stephanie your use of the double negative is a bit confusing here.

  230. #231 Greg Laden
    December 25, 2009

    Orin,

    Just one last comment to you before you have to go…. on the twin data. You have yet to actually provide a single reference to a thing you’ve said. Some of what you have said (about various topics) is from valid sources (I know this because I’m rather familiar with the literature despite rumors to the contrary) but generally taken out of context. I don’t appreciate having my site hijacked by you for the publication off dozens of paragraphs of largely unattributed and generally poorly contextualized and misinterpreted racist propaganda.

    It is politically incorrect for me to allow that to continue.

    Regarding the validity of the twin data: Yes, all the separated twin data sucks, so using some subset of it that sucks more vs. less does not affect the results as well. Indeed, the seprated twin data is one of the best examples out there of race-driving wishful thinking.

    Thanks for your contribution.

  231. #232 Greg Laden
    December 25, 2009

    On this lovely Christmas morning, as I sit here watching Huxley grinning in his sleep for whatever reason, I have received a half dozen terribly insulting and over the top comments on this thread (which I’ve deleted). It has become obvious to me that this argument is played out, and I don’t write this blog to provide a place for racist shits to tell me how unfair I’m being to them, or what I know and don’t know, and so on. I am therefore closing comments on this thread.

    Although none of the notes I received and deleted are from “Bryan” he has complained suddenly that I should not be deleting comments. In other words, the only reason “bryan” could know that I’ve deleted comments is if he was using various IP addresses and fake names to make those very same comments. Therefore I am led to believe that it is he who is making these inappropriate remarks. Interesting. Dishonest. Typical.

    In the future, not to far off, I’ll certainly write another post on this topic and welcome commentary.

    To all my regular readers: I fully expect Bryan and his friends to start commenting now on other threads on this site, and to make a general nuisance of themselves. Between the AGW denialists and the Racists, it may become necessary to require registration on this blog. Perhaps this is a good time of year to make this transition anyway. I apologize in advance if that has to happen.

    Merry Christmas to all!

  232. #233 KevinD
    December 29, 2009

    I would say that this is a great post on an important topic except for one thing: your misuse of the term heritability.

    Heritability as a technical term is the ratio of additive genetic variance to total phenotypic variance for the trait in question. So, if measured correctly, heritability is definitely a measure of genetic inheritance. In fact it is designed to be an estimate of the proportion of the similarity between relatives that is due to genes.

    Calculating heritabilities accurately is not easy in the best of situations and is not really possible in humans. The best techniques for doing it are either a selection experiment or a full sib/half sib breeding experiment, either which would have to be carried out in a way in which the environments of all individuals were as controlled as possible. Human studies can only crudely estimate upper bounds to heritability because it is not possible to experimentally control the environment or to set up genetic crosses.

    Twin studies are useless for calculating heritability not simply because of the problem of a shared environment. Twins also shared an identical pre-natal environment and have identical genomes. This conflates genetic variation due to dominance and epistasis (neither of which is passed directly from parent to offspring) with the additive variation that is directly inherited.

    This doesn’t affect the substance of your post in anyway but your use of the word heritability is going to be quite jarring to quantitative geneticists.

  233. #234 DK
    January 1, 2010

    As always, Greg demonstrates his lack of basic knowledge in biology. As in the very beginning:
    It is scientifically incorrect and probably academically dishonest to assume or insist that a high heritability value means that something is genetic. It often is, but it need not be.

    Now let’s look at the dictionary definition:
    “Heritability” – the proportion of phenotypic variance attributable to variance in genotypes.

    So, Greg, please explain again how it is in your opinion something that’s attributable to the variance in genotypes is not genetic?

  234. #235 Observer
    January 5, 2010

    ***it is impossible to imagine how intelligence can be inherited in such a way as to explain the variability we see in the most inter-group differences. That there is some genetic component is not impossible, but it is very hard to maintain the idea that it is genetic and ethnic, or genetic and racial, or genetic and explanatory of more than a few IQ points in most people. There are no genes, there are no developmental mechanisms, that have been identified.***

    One explanation is:

    0) intelligence is partially heritable (estimates for heritability of IQ are between 0.2 and 0.8 so between 20% and 80% of the variation in IQ is due to variation in genes)

    1) there is plenty of extant genetic variation, probably due to a large number of genes of individually small effect — no additional mutations are required

    2) selection can act if reproductive rates are impacted by these genes

    3) simple estimates suggest that 50,000 [years] *could have* been enough time to produce .5 SD (genetic) group differences

    See here for some elaboration on (2) and (3) using Greg Clark’s (economist at UC Davis) data on English inheritances and family size:

    http://www.econ.ucdavis.edu/faculty/gclark/papers/JEH2006.pdf

    The simplest model would be that time since development of agriculture varies between groups, and this variation leads to different levels of selection for traits which might be more useful for agriculturalists than for hunter gatherers.

    The question is whether one can *exclude* possibilities based on current evidence.

  235. #236 Faye Kane, Idiot Savant
    March 15, 2010

    First of all, do you have any reason to call Rushton names, other than you don’t like the peer-reviewed statistical results he published?

    The data he used is publicly available. It came from NASA and the U.S. military. You can run statistics on the data yourself. If you do, you’ll get the same answers.

    Yet you dismiss everything published in prestigious academic journals merely because Rushton is on the board of directors(!)

    Do you expect any intelligent person to take you seriously?

    But never mind that.

    Hey, you remember the “scientists” at Padua University who refused to look through Galileo’s telescope? You know the contempt you feel for the sniveling cowards?

    I’m going to tell you soemthing you didn’t know, and In 20 seconds, that willl be YOU!

    The outrageous FACT that I’m about to tell you is not talked about outside academic journals *EVER*. it WAS acknowledged as true by Richard Nisbett, the major opponent of Rushton and the “genetic intelligence” model. He’s the main guy on “your side”. He’s the one who makes the bend-over-backwards explaniations you people use when you argue that there is no genetic race/intelligence link.

    It’s also acknowledged as true by Ulri Neisser, Chair of the APA’s Task Force on intelligence,. Neisser, U. (1997). Never a dull moment. American Psychologist, 52, 79–81.

    You will angrily reject this out of hand. You will call ME names. But when you do, I want you to think about the “scientists” at padua, and

    ==[ But you WON’T be able to explain WHY you reject it.

    Okay, ready?

    According to dozens of published, peer-reviewed, duplicated MRI studies using standard volumetric software, blacks average 5% smaller brains than whites, and 6% smaller than Asians. No, it’s not the environment. The deficit is seen in embryos just weeks old — and it’s seen globally and independent of what the mother eats/drinks/does.

    The results have been duplicated many times all over the world using different brains, and verified three completely different ways (brain weight at autopsy, etc.) It is not disputed by scientists any more.

    Oh, and it turns out that blacks have smaller heads, too. I bet you like THAT even less!

    Just a FEW of the dozens of sources:

    Harvey, I., Persaud, R., Ron, M. A., Baker, G., & Murray, R. M. (1994). Volumetric MRI measurements in bipolars compared.

    Beals, K. L., Smith, C. L., & Dodd, S. M. (1984). Brain size, cranial morphology, climate, and time machines. Current Anthropology, 25, 301–330.

    Ho, K. C., Roessmann, U., Straumfjord, J. V., & Monroe, G. (1980). Analysis of brain weight: I and II. Archives of Pathology and Laboratory Medicine, 104, 635–645.

    Johnson FW. Race and sex differences in head size and IQ. Intelligence 1994; 18: 309-33.

    Simmons K. Cranial capacities by both plastic and water techniques with cranial linear measurements. Hum Biol 1942; 14: 473-98.

    Joiner TE. Head size as an explanation of the race-measured IQ relation: negative evidence from child and adolescent samples. Sci Rev Ment Health Prac 2004; 3: 23-32.

    Rushton JP. Mongoloid-Caucasoid differences in brain size from military samples [and NASA]. Intelligence 1991; 15: 351-9.

    Rushton JP. Cranial size and IQ in Asian Americans from birth to age seven. Intelligence 1997; 25: 7-20.

    …and ZILLIONS more.

    If you’re curious as to why this is true, which you’re not, the reason is that the first humans were black, and whites/Asians evolved from them 100,000 years later. That’s right, whites evolved from blacks, who evolved from apes, which evolved from monkeys.

    A summary of this and other research which will make you even angrier is here: The American Psychology Association report: http://tinyurl.com/raceintelligence

    But you won’t read it.

    And you can’t explain why.

    Hey, you remember the “scientists” at Padua University who refused to look through Galileo’s telescope?

    That’s YOU!

    –Faye Kane, idiot-savant
    http://tinyurl.com/whybeingrealsmartsux

  236. #237 Josh
    August 2, 2011

    Oh for fuck sakes, if you believe the HBD crap, YOU’RE WRONG! End of story!

  237. #238 Chuck
    November 19, 2011

    “Katherine, I’ve read that literature. Variation in intelligence is highly heritable. It is only barely genetic.”

    Wow. It’s amazing that you were arguing this in 2009. Has the Davies (2011) study changed your mind? (i.e. “Genome-wide association studies establish that human intelligence is highly heritable and polygenic?)

  238. #239 Greg Laden
    November 19, 2011

    Davies is just another in a long line of studies that show the same thing: Variation in intelligence can not be narrowed down to genetic variation unless you account for it as the result of a VERY large number of individual genetic influences each having a miniscule effect. In other words, variation in intelligence varies across varying individuals.

    It is sort of like using a polynomial to predict a relationship between two variables with the same number of coefficients as variates.

    And, this is why this particular paper is published in one of the classically self serving self referencing old boys clubs journals,

  239. #240 Chuck
    November 19, 2011

    “Davies is just another in a long line of studies that show the same thing: Variation in intelligence can not be narrowed down to genetic variation unless you account for it as the result of a VERY large number of individual genetic influences each having a miniscule effect. In other words, variation in intelligence varies across varying individuals.”

    I don’t get your point. You criticized conventional methods of deriving heritability estimates (i.e. comparing MZ together, DZ together, MZ apart, DZ apart, siblings together, siblings apart, and unrelated individuals reared together) on the grounds that genetic similarity is confounded with environmental similarity (Which doesn’t explain the MZ minus DZ correlation, etc). The Davies study
    circumvents all these kinship nitpickings, by using unrelated individuals. (If you’re not familiar with the methodology used, you can read Visscher’s discussion here: http://homepages.ed.ac.uk/qgjc/2010_2011/CommentaryOnYang.pdf)

  240. #241 Chuck
    November 19, 2011

    Davies estimates that the lower bounds of the narrow heritability of g is .45, making variance in it both highly heritable and highly additively genetic. If you have technical criticisms of or objections to the methodology — and not just snarky comments — I would appreciate if you could detail them. I haven’t been able to find any either on the web or in journal articles.

  241. #242 Greg Laden
    November 19, 2011

    I’ve made my technical criticism and you’ve responded by saying that you don’t understand.

  242. #243 Chuck
    November 19, 2011

    “Variation in intelligence can not be narrowed down to genetic variation unless you account for it as the result of a VERY large number of individual genetic influences each having a miniscule effect..”

    “I’ve made my technical criticism and you’ve responded by saying that you don’t understand.”

    I don’t see how this is a critique of the findings or how this supports your statement that “Variation in intelligence … is only barely genetic.” The authors fit the phenotype as a function of a large numbers of alleles modeled as a random effect. The equations used are explained in the linked paper. Perhaps, you could spell out your critique so I can email the authors and ask for their opinions of it.

  243. #244 Michael Mifsud
    May 5, 2012

    The intelligence argument may not be a question of genetics although it depends, in my estimation, on what we consider intelligence to mean. Would we be talking in terms of a fast brain or one produced by systems that render it easy to create networks etc? Or would we be talking about components that are crucial for all this ? All that could be genetic. However, where I think that there is a great deal to be studied with respect to races, family derived communities and closed ethnic groups. Evolution produced a wide variety of changes for good and bad and if some of the bad managed to prosper and their genes trapped in cultural defence then the emerging societies would without doubt if certain factors were in play, be backward or stulltified as shown by certain nomadic groupings which have been incapable of adapting to modern life and social facilities. I am sure that in places where cultural stronghold villages set apart and which prevented intermarriages with similar, kept their genetic stock trapped in the format which reflected its origins. I am therefore willing to assume that some countries and some races are backward because brain centres associated with say spacial and emotional control are not fully developed. This is not to say that ALL its members are in the same condition but by virtue of the cultural barriers, the main reaction in teh attempt to communicate with them is that they are incapable generally as a community of reflecting the sort of refined qualities one would associate with highly evolved people. In short, I am inclined to believe that brain studies would reveal this.

  244. #245 Chris
    August 28, 2014

    This is an old article, but something I’ve always been curious about.

    There’s always an issue of racism to be concerned with, but one could make the argument that people are afraid to tackle this subject for fear of being labeled a racist.

    You wouldn’t see anyone dispute certain breeds of dogs are smarter than others, yet they all belong to the same species. It’s not far fetched to think that there may be differences between different human races.

    Those from Asian territories are typically smaller In stature than Caucasians. Africans are typically more athletic than either Europeans or Asians.

    The brain is also a physical thing. We don’t understand its workings, but it is a body part like any other. If we can see differences in breeds of dog and differences in our own physical abilities, why would it be hard to believe there are differences in intelligence?

    Now, logically, we should note that these would be cases of averages.

  245. #246 Greg Laden
    August 29, 2014

    Chris, you are suggesting that humans vary by race in intelligence and you are providing specific reasons you think this may be true. You are also using physical variations in humans, by race, to suggest that there may well be racial variations in intelligence because brains are just organs, body parts, like other organs. But you have a lot of this wrong.

    First, there is not consensus or a scientific basis for saying that some breeds of dogs are more intelligent. Human intelligence is a function of human cerebral executive processing in the brain. Dogs don’t have that part of the brain, so they can’t have human intelligence. Also, despite the general belief that different breeds of dogs have different characteristics, there are very few systematic scientific studies that show this. One of the most important differences among dogs, for example, is levels of aggressiveness and likelihood of biting. But we know that dogs are generally raised to be more aggressive or bity, it is not innate. So the argument that dogs have races and they vary therefore human races can vary actually gets strikes against it when we refer to dogs. In other words, variation across dogs in their behavior is best explained by upbringing and experience, not innate features. So if dogs were relevant, they’d be on the negative side of the list of pros and cons of your argument.

    Brains are not like other organs. To some extent,any given type of organ grows and develops to become a functioning, “adult” or complete organ based on its environment interacting with genes. But most of those environmental factors for most organs are developmental features of the animal the organ is developing in.For example, a set of cells that would normally be a leg can end up being a wing if you move them to where wings would grow, on an embryonic bird. But if you move the cells later in development, you just get this extra wing because the cells have more or less finished receiving their information from the environment.

    Brains are like this too. They develop into a particular brain based on the environment in which they grow. A brain of a mammal that for some reason has no legs at all will fail to develop the parts of the brain that normally deal with legs, if the legs are not there from the beginning. If the legs are removed later, you’ve got brain leg bits but they are (obviously) not working with legs because they are gone.

    The “thinking” parts of the brain, the intelligence and other bits, develop in humans exceptionally late compared to other mammals or even other primates. This development happens in the cultural, social environment in which the brain is growing to adapt to that situation. Variation across humans in intelligence and other behavioral features has been shown in numerous studies to be partly random and otherwise mostly or even entirely explained (depending on the feature) by environment, that variation is generally no innate.

    So your reference to organs, when it is developed with what actually happens, is an argument against, not in favor of, innate variation in humans by race. Also, your argument that you could be right about race because we don’t really know how all this works is not an argument (we can’t assume something true based on not knowing it is true) and is wrong anyway because we actually do know a fair amount about how this works.

    You have used stature arguments to exemplify human racial variation. The race terms you use are invalid, ancient, not real, inaccurate characterizations of humans. There is no “asian” race, for example. People we call “asian” include the Andaman Islanders, the Tamil from Shri Lanka, Russians, Japanese, Ainu, Chinese, Indonesians, and so on. Same with “African.” There is more variation across humans in Africa than the rest of humans combined times about ten.

    Usually when people from cultures where everyone is short move, as babies, to regions where everyone is tall, they grow up to be taller than they “shoulld.” When they have babies, their offspring are also taller, and this happens for a few generation (maybe two or three, usually not more) until everyone is the height of their new context, not their old context. Variation across humans in height is explained primarily, really close to 100% in most groups, by environment, it is not innate. So that part of your argument does not stand.

    Then, there is the problem of “race.” As already noted, your race categories are invalid. One might think one could get new categories that are better. One can indeed get categories of humans that work somewhat better, but the degree of clear distinction between groups varies, with some groups simply not being groups but rather fading into the other groups. The more clear distinctions tend to be a function of historical events, and based on the archaeology they change dramatically over time. Races lack clear boundaries (or in many cases, any boundaries) and they change over time through more variation than we tend to see across space at a given moment of time. Biologically speaking, race is simply not a good attribute for humans. It is for dogs only because they are bred, and it mainly applies to those that are either pure bred. Lacking draconian and intentional breeding, dogs revert to a much less differentiated form in a very short number of generations depending on circumstances.

    So, now you know!

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