Rushton on Race and IQ

Greg, you're omitting the East Asian data which is part of Rushton's theory? That forms part of his 'rule of three' that average differences, be it physical, mental, developmental, temperamental,or behavioral that can be found between Asians and Europeans, a similar relationship will most likely be found between Europeans and Africans.

So you would end up with the claim that East Asians are more evolved in the 'advanced' direction.

I am pretty sure that ignoring the East Asian data does not detract from or alter what Rushton is saying or what I'm saying, but if anyone needs to know it they can find it.

Yes, East Asians would be more evolved in the advanced direction according to Rushton. I'm focusing on the African/White/African-American claim because that fits much more closely with my own areas of expertise.

Oooh - an evolution claim - now where's his evidence? Yeah, I didn't think he had any. Why do people who know absolutely nothing about evolution like to make such absurd claims that "evolution accounts for this, evolution explains that" and yet have absolutely no evidence. Even Darwin was pretty careful about making statements about what can be explained by evolution - and he was wrong on some things and over the years various tools were developed to test some ideas too. Yet the people who see evolution as a mysterious black box just love to make ridiculous statements and claim that evolution supports their stupid ideas.

You have to wonder - do such morons have a propensity to become "psychologists"? Rushton, MacDonald - are there more?

I am reminded of another discussion on this blog:

http://scienceblogs.com/gregladen/2009/06/cat_origins.php

It's the same sort of argument.

Me: That evidence is entirely inconclusive based on everything you've just told me. This works just as well for the pro-African argument as the anti-African.

Them: But if you look at this evidence in conjunction with other evidence, it makes a much better case.

Me: Ahem. If it doesn't tell us anything, it's not evidence at all and shouldn't be cited.

An example from a paper Observer cited here:

Them: We've identified several genes as being involved in intelligence. None of them have stood up as anything other than statistical artifacts under replication, but we're getting closer.

Me: WTF? You're not getting closer to anything. You're just validating the well-known critique that these types of tests are prone to statistical artifacts!

Them: And here's a review that uses this information and cites another few dozen papers. How can you argue against it?

Me: Do you know what science is?

JL Graves takes apart Rushton's evolutionary scenario to account for these presumed differences (Chapter 3 of "Race and Intelligence: Separating science from myth"). Rushton's major problem is that he *thinks* he understands life history theory when in fact he doesn't. Also, his linkages between cold climates and selection for intelligence are very debatable. r-K theory separates all of biodiversity along a single axis...but of course, it's just that simple! [note sarcasm]. Most folks have moved away from trying to parse life history strategies into r and K, or even "fast" or "slow" for that matter. These dichotomies are useful heuristics when comparing disparate species, but they breakdown and/or don't even apply to within species variation.

Since female human brains are smaller then male human brains, then by Prof. Rushtons' theory, males must have higher IQs then females.

Of course, Neanderthals had larger brains then modern humans so they too must have had higher IQs then modern humans by Prof. Rushtons' theory. I doubt that he will find much support for that.

SLC: If you look back through the comments on this blog, you'll find a fairly cogent description of the male vs. female IQ testing by Bryan Pesta (who does this sort of thing for a living) in which he discusses how tests are conducted and adjusted.

IQ testing has had a very bad history of being abused, used wrong, and so badly written as to be essentially useless.
before I accepted anything this guy said I would want to have a hard look at his so called IQ test.

In the wake of James Watson's ramblings a few years back, William Saletan posted a somewhat infamous series on Slate. After releasing all of his 4 part series, which was based on Rushton and apparently spoon-fed to him by Sailer, he issued a quasi-retraction to the effect that he was no scientist, so how could he have known, etc.

http://www.slate.com/id/2178122/entry/2178123/

I think this is the most bizarre journalism of recent decades. The errors in judgment and data are actually quite a bit less disturbing than the errors in moral or policy judgment. (He rather flippantly assures us that genocide is off the table nowadays. At least I think.)

I think this is "on-topic"; I found it especially helpful as an emblem of the way racialist research is being used/going to be used by policy makers and journalists.

There's nothing new about Rushton's research. Racist views about intelligence and hereditary fitness date back to the 19th century. Francis Galton and his eugenics theories have a continuing legacy. So long as organizations like the Heritage Fund subsidizes research like this, there will be researchers to take advantage of it.

http://drvitelli.typepad.com/providentia/2009/10/saving-civilization.ht…

***Rushton and apparently spoon-fed to him by Sailer, he issued a quasi-retraction to the effect that he was no scientist, so how could he have known, etc.***

Yes, when you start getting tonnes of hate mail, or your job is on the line, that tends to happen.

You need to read Saletan's subsequent articles to see his true position is more nuanced:

"Five months ago, I wrote a series on race, genes, and intelligence. Everything about it hurt: the research, the writing, the reactions, the regrets. Not a day has gone by that I haven't thought about it. I've been struggling to reconcile two feelings that won't go away: that what I wrote was socially harmful and that I can't honestly renounce the evidence I presented."

Or in relation to the achievement gap, where Saletan argues that focussing on race gaps in achievement are unhelpful:

"On this question, I'm in no position to throw stones. I've come to my cautionary view the hard way. Liberal creationistsâpeople who think no genetically based difference can be admitted in average ability between populationsâare mistaken. But that doesn't make race a useful or socially healthy way of categorizing people."

http://www.slate.com/id/2217996/

The problem here is the difficulty in facing the facts ... in words spoken out loud or written for others to see ... that the 70-80-100 model is not what is supported by any of the data, is often not what is specifically cited as the conclusion for any recent research, but is what is always on the minds and in the hearts of race based scientists who want black people to be a different subspecies than white people: An intellectually inferior subspecies, a morally inferior subspecies, an r-strategist promiscuous animal-like subspecies.

No, I don't think that is fair. As Saletan points out in that article, if policy makers want to focus on the cause of achievement gaps then you can't blame researchers for looking at data in that manner. That is after all what got Jensen looking at it. He was asked by the Harvard Educational Review to examine the results of HeadStart and the achievement gap.

Sometimes they just resort to irrelevant distractions. But they never DENY that they believe in the 70-80-100 African/Black American/ White American deeply ingrained genetic spread model. They just let it sit there, glancing at it, wiggling their eyebrows at it, but never quite denying it. Because it is what they believe.

Well, this is why I mentioned the East Asian data in my initial comment. Do you believe that Rushton *wants* caucasions to be a "different subspecies than East Asian people: An intellectually inferior subspecies, a morally inferior subspecies, an r-strategist promiscuous animal-like subspecies."?

Observer, while I think that Saletan's problem was not the people complaining, but rather his lack of diligence in his initial research. I think that Saletan should have issued a retraction of his entire article. I'm sorry if people were mean to him, but he had nobody to blame for that but himself:

As he says:

But the thing that has upset me most concerns a co-author of one of the articles I cited. In researching this subject, I focused on published data and relied on peer review and rebuttals to expose any relevant issue. As a result, I missed something I could have picked up from a simple glance at Wikipedia.

For the past five years, J. Philippe Rushton has been president of the Pioneer Fund, an organization dedicated to "the scientific study of heredity and human differences." During this time, the fund has awarded at least $70,000 to the New Century Foundation. To get a flavor of what New Century stands for, check out its publications on crime ("Everyone knows that blacks are dangerous") and heresy ("Unless whites shake off the teachings of racial orthodoxy they will cease to be a distinct people"). New Century publishes a magazine called American Renaissance, which preaches segregation. Rushton routinely speaks at its conferences.

Observer, everyone understands that the mild superiority of "orientals" over "whites" in the racist model that you and Rushton and others support is nothing but cover for the large superiority of "whites" over "blacks" and especially "africans." Nothing but cover.

Actually, many of the key players in this circle jerk of "evidence" not only don't reject the 70/85/100 model, they explicitly embrace it in all its eugenic implications. FAIR did a great job, back when The Bell Curve came out, of documenting it. They've also included a lovely write-up on Rushton's penis obsession and his reaction to the idea of getting IRB approval.

***I think that Saletan should have issued a retraction of his entire article.***

But as I noted in post #11, Saletan doesn't actually renounce the evidence presented by Jensen & Rushton in their 60 page review paper. The arguments against for and against were well canvassed by Saletan in that series of articles.

The entire June 2005 issue of Psychology, Public Policy, and Law, Vol. 11, No. 2 is dedicated to that subject. You can read the commentaries of Robert J Sternberg, Richard Nisbett, Linda Gottfredson, Aronson & Suzuki in that issue (easily located on the web).

I apologize for posting yet again, but what I meant to get at above is that Saletan's evidence *was* the Rushton review that he disavowed later, which is why I said a retraction was indicated--and not simply an apology. What he (Saletan) has written since is interesting: in particular, this May 2009 article shows he's still very much interested in race/iq:

http://www.slate.com/id/2217571/

He relies (again?) on Sailer for much of his content.

Sorry for posting several times, but Observer referred to Saletan's later work: just giving the link.

Aren't these discussions - besides discussing the current data, methodologies and the scientists involved - also showing an overarching problem. Could it be that it is these topics where responsible research must end?

Let me explain. In the best of all worlds, we'd have an ideal research opportunity for these kinds of traits: readily available genetotypic and phenotypic variability in large, easily accessible populations. All the experiments/data are there for the taking. Mathematics, statistics and computational methodology is around from many other fields and the numbers at our disposal are large.
Yet, obviously, the social implications of any results are so huge, that most scientists would rather spare themselves the headache (I just discussed this with neuroscientist colleagues over the weekend and most of them wondered why anybody would chose to go into this minefield voluntarily).
Isn't that ironic?
Compounding this ironic dilemma is the psychology of human performance. Divide a group of, e.g., girls randomly into two sub-groups, one of which gets a neutral text to read and the other a text which explains why girls are worse in math than boys (don't have the reference handy, sorry). When both groups of girls get the same math test, the girls with the neutral text score higher than the girls in the other group.
This means that if research ever found any tenable genetic link between any sort of recognizable populations and any sort of cognitive score, no matter how intricate or practically irrelevant, the result would have the tendency of becoming a self-fulfilling prophecy and almost impossible to falsify. Indeed, much of the differences we measure today may already just be due to this psychological phenomenon.
So, are these topics where responsible research must end? Is "let's just not go there" the responsible and cautionary way of dealing with the dilemma?

Re Greg Laden @ #7

I think that Dr. Laden is misinterpreting my comment which in no way, shape, form, or regard was suggesting that female humans have lower IQs then male humans. It was merely pointing out the fallacies in Prof. Rushtons' theory.

Actually, far more important then brain size is the ratio of brain size to body size, which is summarized as the encephalization factor (which averages about 7 for both male and female humans as female humans are considerably smaller then males on average). Another factor of importance is brain organization. As best we can tell, the organization of Neanderthals was considerably different then for modern humans, which may, in part, explain why homo sapiens were able to out-compete homo neanderthalis.

@SLC

This is off-topic, but yesterday on CBC radio's "Quirks and Quarks", there was an interesting discussion with Clive Finlayson, talking about the hypothesis that the fall of the Neanderthals may have been more affected by location, climate and ecological aspects than competition with Homo sapiens ... (I haven't read his book, but have added it to my ever-growing list o' stuff I want to read!)

The podcast is available:
Quirks & Quarks January 9, 2010

Oh, back the main topic, I think I need to re-read Gould's "The Mismeasure of Man" again ...

SLC, part of Greg's point is that Pesta cites Rushton's "research" on male vs. female IQ, stating that although IQ tests are set up to eliminate gender bias, he thinks there are some studies that show women have IQs about three points lower than men on average. At least, I assume he's citing Rushton, since I haven't seen any other studies showing that gap.

Re Sephenie Z

Prof. Rushton is clearly a quack as he fails to consider both encephalization factor and brain organization. However, I got a big laugh out of his citing a supposed "more insatiable sexual appetite in the black community". Tell that to William Jefferson Clinton, Albert Einstein, and Richard Feynman.

A few points (based mainly on my review of his initial stuff 20 years ago, but also my astonishment that his narrative has changed so little in 20 years, which is a red flag that this may not be science).
1. The numbers presented aren't bad as a first quick pass, but convey very little science. For example, his technique has been to take the highest and lowest number of a given 'group', and average them, then average between male and female values. However, he shows no interest in some of the confounds that will affect the data on brain size (for example). There are secular changes in brain size - we have larger average brains than we did 60 years ago, probably reflecting changes in nutrition. There have been differences between countries, and some have shown marked changes in IQ and body stature over the last 50 or 60 years, while others show less change. Select your data carelessly, and you can come up with some interesting trends that support a narrative, but aren't science.
2. Sex differences are an interesting counterexample. Men have larger brains than women, IQ differences are relatively small overall, but tend to go in stereotypical ways (on average, men slightly better on spatial tasks, women slightly better on verbal tasks). Given these findings, what can we make of the fact that 50 years ago, relatively few women attended higher education, and those who did generally did not get a career or even a degree? My mother had a daughters of the confederacy scholarship (do they even have such things now?), which she had to push for each year, because she was engaged, then married, then pregnant, then had a newborn, and in each case, of course she wouldn't need further education. After 50 years, the majority of university students, at least in North America, are female, and it's not because their brains have grown. Similarly, I'm impressed by the number of engineers I've met from the old Soviet bloc, as compared to North America (or Australia, where we had 1 women out of 41 students in our first year engineering class, circa 1980). Change the social context, and the results change.
3. The link between brain size, IQ, and social outcomes is too small to explain the social outcome. The correlation between whole brain size and IQ is about .3. The expected IQ differences between groups, if they were valid, is about 2-3 points. The expected difference between social outcomes, based on IQ/brain size, is smaller yet.
4. Rushton works hard to avoid counterexamples. For example, data from the US somewhat supports group differences, but not data from Canada (Longman, Saklofske & Fung, 2007 http://www.ncbi.nlm.nih.gov/pubmed/17986660). Raven's matrices work on asian adoptees in Belgium shows a strong superiority in spatial reasoning (goes with the narrative), but it happens to be exactly the same for the general population (the Flynn effect is strong on the Raven's matrices), while German children born of African-American fathers show the same IQ scores as their 'Aryan' peers (Scarr, S., R. Weinberg, and I. Waldman. 1993. IQ Correlations in Transracial Adoptive Families. Intelligence 17: 541â555.) Why not look at better data from actual experts, for example Culture and Children's Intelligence? And suddenly, there's a huge focus on cultural issues, changes and explanatory factors, not a slim rehash of ancient data that avoids social factors.

I'm baffled by this post.

Rushton and others who agree with him at least in part on these issues, such as Jensen, reference the studies upon which they base their inferences.

Why act as if it's some cosmic mystery what the data might be that supports the view? If that's your concern, go to those references, and criticisms thereof.

My general sense of the literature here on brain size and its relation to IQ -- with which I'll admit I'm not greatly familiar myself -- is that it seems to support a modest correlation between the two. Of course, even a modest correlation tends to be a real problem for those who believe in equality in innate cognitive potential across groups or (even more radically) across individuals: why should there be any correlation at all, if all groups and/or all individuals are equal at birth?

I think, though, that the science is getting quite a bit more sophisticated than crude measures such as brain size. The evidence seems to be mounting that IQ is more precisely correlated with the quality and quantity of white matter in the brain, of which brain size is at best a rather erratic measure. See the following articles for details.

http://www.technologyreview.com/biomedicine/22333/

http://www.technologyreview.com/biomedicine/23695/page4/

These scientists have discovered pretty strong genetic bases for the quality of the fatty tissue surrounding the neural wiring in various regions of the brain clearly connected to cognitive functioning. They are starting to identify more precisely the exact features of this white matter that correlate best to IQ itself. It certainly seems to be anticipated that those features will likewise have a genetic basis.

The belief in innate equality pretty much entails the assertion that this final scientific endeavor is doomed to fail; if it succeeds, I don't know how one recovers a possibility that innate equality can be real.

I think it's worthwhile for people to ask themselves: on what a priori ground might I be right to assume that that scientific endeavor must fail? If one can't find a persuasive a priori ground, isn't the most plausible outcome that scientists will, indeed, find such a connection, given what they have already discovered about the genetic basis of white matter?

Sorry for posting several times

...um, why?

So, are these topics where responsible research must end? Is "let's just not go there" the responsible and cautionary way of dealing with the dilemma?

I think what they've found is that educating people about this "priming" effect undermines it, perhaps even reverses it (see here for a good write-up). Maybe we just ought to really drill the concept into people's heads in school.

It certainly seems to be anticipated that those features will likewise have a genetic basis.

Given the abundant evidence of radical environmental and stimulation-related impacts on the growth and development of human brains, does this anticipation imply anything more than "really, really, really wish it were true?"

Why act as if it's some cosmic mystery what the data might be that supports the view? If that's your concern, go to those references, and criticisms thereof.

I am baffled by this remark. Do I smell a concern troll or a how to blog troll?

My general sense of the literature here on brain size and its relation to IQ -- with which I'll admit I'm not greatly familiar myself -- is that it seems to support a modest correlation between the two.

You could be drawing a very very important conclusion on the basis of what you admit to be a guess. The larger discussions going on here (on the several posts on this topic) are: 1) The ways in which the race-loving race-based boosters (some of whom claim to be scientists) promote their work, and that is the point of this post (I'm still waiting for an answer to the essential question ... and I'm pretty sure there won't be) and 2) (less explicit in this post) is the huge disconnect between what we know about how brains develop and how evolution works that make Rushton's mmodel not only unlikely but rather laughable.

Your innate equality is a straw man, and the link between race-based genetic models and white matter is spurious at best, I'm afraid.

There does seem to be an endless supply of people willing to insist that "Oh, I don't really know, but it is clearly proven" but who otherwise come out of nowhere. I don't really care about pseudonymous posting much but it is interesting that the people willing to put their names behind what they are saying are common on the non-race based "side" of this and very very rare (Bryan Pesta being one of the refreshing exceptions) on the racialized side of this.

So, again, I come back to the basic question off this post that no one has addressed:

Is Rushton's model valid, as given in his abridged book and represented here. Are these IQ data good? Are these brain size data good? Is the correlation valid?

Or is it not so good, maybe even fairly crappy data and not a very good analysis. The literature on this topic uses this reference regularly and uncritically. Is the uncritical use of this analysis OK?

Bryan? Observer? Anybod?

*** 'Aryan' peers (Scarr, S., R. Weinberg, and I. Waldman. 1993. IQ Correlations in Transracial Adoptive Families. Intelligence 17: 541â555.) Why not look at better data from actual experts, for example Culture and Children's Intelligence? And suddenly, there's a huge focus on cultural issues, changes and explanatory factors, not a slim rehash of ancient data that avoids social factors.

Posted by: stewart | January 10, 2010 11:43 AM

***

Stewart,

Regarding the slim rehash of ancient data, are you referring to the 2005 30 year review paper cited at #19 above?

Also, WWII Eyferth study has a few problems (which are mentioned in the review paper & were first mentioned at least in the 70's):

* Although the children's IQ was measured, the parents' IQ was not measured (neither was the rank of the US military father measured). So it is not known whether the children inherited the parental IQ.

* About 30 percent of US blacks failed pre-induction mental tests for the military, compared with 3 percent of white. So US black soldiers were a more IQ-selected and less-representative sample of their population than were white soldiers.

* Children were tested prior to the age at which the genotypic aspect of intelligence has become fully manifested.

***"It certainly seems to be anticipated that those features will likewise have a genetic basis."

Given the abundant evidence of radical environmental and stimulation-related impacts on the growth and development of human brains, does this anticipation imply anything more than "really, really, really wish it were true?"

Posted by: Azkyroth | January 10, 2010 2:41 PM***

Azkyroth,

I think he's basing that on what studies to date indicate - from the link at #27:

"The UCLA researchers took the study a step further by comparing the white matter architecture of identical twins, who share almost all their DNA, and fraternal twins, who share only half. Results showed that the quality of the white matter is highly genetically determined, although the influence of genetics varies by brain area. According to the findings, about 85 percent of the variation in white matter in the parietal lobe, which is involved in mathematics, logic, and visual-spatial skills, can be attributed to genetics. But only about 45 percent of the variation in the temporal lobe, which plays a central role in learning and memory, appears to be inherited.

Thompson and his collaborators also analyzed the twins' DNA, and they are now looking for specific genetic variations that are linked to the quality of the brain's white matter. The researchers have already found a candidate--the gene for a protein called BDNF, which promotes cell growth. "People with one variation have more intact fibers," says Thompson."

Children were tested prior to the age at which the genotypic aspect of intelligence has become fully manifested.

This is the funniest thing I've seen all day and I'm watching the Baltimore/NE football game!!!!

HAHAHAHAH!!!!!!!!!!!!!!11!!

Ok, that sentence may sound a bit silly. All I'm saying is that heritability of general cognitive ability apparently increases from childhood into adolescence. There's a recent paper by Plomin ('The heritability of general cognitive ability increases linearly from childhood to young adulthood' Mol Psychiatry. 2009 Jun 2) on this:

"The heritability of general cognitive ability increases significantly and linearly from 41% in childhood (9 years) to 55% in adolescence (12 years) and to 66% in young adulthood (17 years) in a sample of 11 000 pairs of twins from four countries, a larger sample than all previous studies combined. In addition to its far-reaching implications for neuroscience and molecular genetics, this finding suggests new ways of thinking about the interface between nature and nurture during the school years. Why, despite life's 'slings and arrows of outrageous fortune', do genetically driven differences increasingly account for differences in general cognitive ability? We suggest that the answer lies with genotype-environment correlation: as children grow up, they increasingly select, modify and even create their own experiences in part based on their genetic propensities."

***I apologize for posting yet again, but what I meant to get at above is that Saletan's evidence *was* the Rushton review that he disavowed later, which is why I said a retraction was indicated--and not simply an apology. What he (Saletan) has written since is interesting: in particular, this May 2009 article shows he's still very much interested in race/iq:

http://www.slate.com/id/2217571/

He relies (again?) on Sailer for much of his content.

Sorry for posting several times, but Observer referred to Saletan's later work: just giving the link.

Posted by: jeff | January 10, 2010 3:29 AM***

Jeff,

Saletan is interested because he thinks it is a bad way of analysing data, but focussing on the achievement gap forces the issue. The lead up to that May 2009 article was:

*The NY Times had an article about the achievement gap

* Some commentators on Sailer's site referred to hereditary differences partly explaining this.

* Saletan did an article about the perils of analysing test scores by race. He noted that inevitably it meant that you invite people to consider whether there are gene-trait correlations and group differences in distribution. Saletan considers that is unhelpful and it would be better if people on the left & right didn't frame issues in terms of race.

Greg,

I should think it might behoove you, as someone blogging under the rubric of "scienceblogs", to find a way to avoid engaging so flagrantly in ad hominem fallacies as your argument of choice.

From your very first accusation of me as being a "concern troll", you simply can't seem to engage the issues, and instead choose to find any way you can to disparage me.

Ever heard of objectivity? Try it some time.

I reiterate the point with which I started my original post: why act as if there is some cosmic mystery about the legitimacy of the data Rushton (and Jensen) appeals to, when you yourself can track down those references, as well as criticisms of them? Is this so hard? If you're interested in the issue, do some work.

And you write this:

I don't really care about pseudonymous posting much but it is interesting that the people willing to put their names behind what they are saying are common on the non-race based "side" of this and very very rare (Bryan Pesta being one of the refreshing exceptions) on the racialized side of this.

First, of course, thanks for the additional snide remark. But let's try a little hypothesis here. Yes, it's likely that many more people who believe there's a good case for a genetic basis in racial differences on IQ choose to keep their identities secret than do those who believe otherwise. I hypothesize that the major reason they choose to do so is that they rightly fear that they will be smeared if they reveal their belief and their identity.

What might confirm that hypothesis? Well, the very kind of smearing in which you are currently engaged. I made my original post as objective as I could; my reward was to be treated to some really pretty ugly ad hominems from you, the blogger. Imagine my surprise.

In any case, as I had said, the science has moved on from brain size in particular -- always a primitive measure by any account, given the relatively small correlation to IQ it coughs up. As the papers I pointed to make clear, brain size is simply a very crude stand in for size and quality of white matter, which seem far more closely related to cognitive functioning.

You write:

Your innate equality is a straw man, and the link between race-based genetic models and white matter is spurious at best, I'm afraid.

You talk about my raising a "straw man" in talking about innate equality. But what do you even mean by that? Do you mean to grant that there is indeed a genetic component to, say, black white differences in IQ, but are simply asserting that the difference is small? If that's what you mean, can you please say so? But here's the problem: if the genetic differences are, by your own account, quite possibly real, but supposedly small, why can't they be quite possibly real, but also quite large? Scientifically, how can you grant one possibility without the other?

And I'll grant that these scientists haven't yet connected these differences in white matter with differences between races. But how plausible is it a priori that these sort of physiological differences in white matter would be genetic between individuals within a race, but not between races? Sure, in principle there might be a difference in how IQ gets cast out in white matter between races, but does it seem plausible? Wouldn't the default assumption be that they are expressed in the same way, not in different ways? Indeed, if they were expressed in different ways, wouldn't that itself be a major racial difference in physiology?

The simple fact is that you must believe that the sort of differences I'm talking about here just can't or won't be discovered as science homes in on how IQ really gets expressed in the brain. That's a possibility, of course, but it's not, I think, what one would be most inclined to believe if one were to look at the matter with the eye of a dispassionate scientist.

Of course, time will tell: as these scientists develop a better grasp on what really contributes physiologically to IQ, and what its genetic basis may be, it will likely become a relatively trivial exercise to determine whether or not these differences fall along racial or gender lines.

In the end, you really are approaching the subject matter here not as a scientist interested in the more likely explanation, but rather as a defense lawyer, trying to throw out into the court of public opinion any kind of objection that might seem to encourage a belief in reasonable doubt.

The problem is that we live in reality, where it actually does matter whether or not differences between groups might be true. Try though we might, we can't make problems go away by denying reality; reasonable doubt won't help us there.

Observer, in the absence of one iota of evidence linking genes we have not identified with allelic variation we can't document to behavior that we know is cortical ... where learning happens .. how exactly do you distinguish between the effects of learning over time and genes over time?????

Answer: You can't.

Still laughing at the utter backwardness of the entire thing.

Rushton is no longer in the vanguard of scientific racism like he was in the 90s. That now belongs to the a subset of the rapid selection school of population genetics. There are some famous names in the fields of biology, psychology, and anthropology. One came out of the closet in the last month. And the bible of the movement made a splash in the science blogs and was widely praised.

Rushton is not exactly a dead horse, but he's not as relevant anymore.

Given the abundant evidence of radical environmental and stimulation-related impacts on the growth and development of human brains, does this anticipation imply anything more than "really, really, really wish it were true?"

I, personally, am amazed that so many people are clueless as to what Scienceblogs is all about and then throw out the complaint that there are ad homs. Is it so difficult to understand, this concept of blogging?

Has Rushton looked at IQ and brain size of North American and South American aboriginals?

According to Rushton's theory, they'd be the fourth evolutionary branch (evolving after the Asians) and, therefore, should have the largest brains and IQs. Yet they're also considered to be about the same level of sub-species as blacks by most of the racists that use Rushton's work to support their racism.

Hey Greg Laden. I printed this science column and juxtaposed it next to one of your blind believing support of global warming science religion columns, and had myself a good laugh.

Thanks! Yer a great truth seeking scientist. Well, actually only when you pre-suppose I suppose.

"biorealist," your original argument was that you didn't understand the post. Rather than ask for help, or paying any attention to the other comments, you attacked Greg, telling him how he should blog based on your inability to read the post. When you behave that rudely, expect to have it pointed out to you.

As for the rest of your original comment, you did, as Greg pointed out, make very strong assertions based on very weak understanding of the literature. Once again, you didn't ask any questions, despite clear indications of an ongoing discussion, but assumed your naive understanding of the research was paramount. It is not.

If you ask nicely, I or someone else will point you to the other pieces of this conversation, where things like twin studies and the reactivity of white and gray matter to the environment have already been discussed. (Or you could just get clever and find Race and Racism under the archives.) This has been going on for weeks; you have quite a bit of catching up to do. Once you've done that, you'll be in a position to comment on objectivity and addressing data. But not until you've done the work. Until that point, you're just repeating things that have already been said and doing it with an attitude of sheer entitlement.

Observer, why do you continue to bring up twin studies as though they were proof of something without acknowledging all the times their weaknesses have been discussed here? Piling up data that don't show anything one way or another is exactly what this post is about, you know.

re:38, In fairness Greg, lots of evolutionary models look only at the phenotype and how it changes over time without needing to invoke the genes responsible and/or changes in allele frequencies--this is the essence of quantitative genetics, it is purely a phenotypic view of evolution and all the "genetics" are phenomenological. These types of models have not stopped folks from trying to hypothesize about the evolutionary origins of particular traits such as intelligence (however measured). For example, we don't have much knowledge about the trait "survival to age 60" in terms of specific genes or their frequencies, but this doesn't mean we haven't been able to develop theories about why "survival to age 60" has evolved in humans.

And now for a post-Green Bay/Cardinals game beer-infused quasi-rant:
To me, there is no problem in suggesting that there is a genetic basis for intelligence. But establishing this in a robust sense is daunting since many many key factors are not accounted for, including maternal effects, rearing environment, indirect genetic effects, nutrition, etc. All the models that I've seen pertaining to the heritability of intelligence have tended to leave out numerous factors.

To be clear, I have no problem accepting that intelligence is heritable, but since heritability is concerned with variance, and IQ tests (or any other measure of intelligence) is concerned with the mean, the two concepts are for the most part talking past each other: intelligence can be modified and increase over development despite being 100% heritable because the mean value and the variation attributed to additive effects are two different things. The idea that some of the variation in intelligence might be due to variation in genes is really not controversial and shouldn't be resisted on ideological grounds, only empirical ones.

And of course, if you believe there is a genetic basis to "race", where race means "black" "white" "asian", you are simply wrong. There are NO genetic data that supports this trichotomy that cannot be contradicted by other data or simply reinterpreted to reveal another grouping. It's really that simple. The general problem is that it is easy to read abstracts and then post citations here; this is all fine and good but looking at the methods of those cited studies reveals so many hidden assumptions and/or simplifications that alternative interpretations are always possible. Always.

Liberal Biorealist, in reading over your response to Greg (#37), you appear to presuppose that humanity can be (or will be) easily and distinctly divided into neat groupings that we might call "races." This is a major problem with your post. I have no problem accepting that 1) there is variation in intelligence, and 2) that part of this variation is due to (additive) genetic effects. This is not a problem. The problem is the data for the racial divisions in the first place. They are simply not there, as I note above. It's insulting to your intelligence for me to point out that if you hold a priori convictions about reality (like the fact that humanity can be divided into genetically distinct races), then it's only a small step to map other perceived trait differences (such as intelligence) onto your preconceived view of reality.

If races are actually proved to exist in the genetic sense then and only then might we want to look for differences in traits among these races; but at present, robust genetic data aren't there to support any racial divisions among humanity. And of course, "race" is not necessarily a genetic phenomenon anyways. There is a large socially constructed component to it, since all studies of race rely on some preconceived idea about which part of the world the researcher should travel to in order to collect genetic samples (or other data) that adequately represent his or her personal idea of where those races are supposed to live and what those races are supposed to look like.

***And of course, if you believe there is a genetic basis to "race", where race means "black" "white" "asian", you are simply wrong. There are NO genetic data that supports this trichotomy that cannot be contradicted by other data or simply reinterpreted to reveal another grouping. It's really that simple.***

Isn't the claim that genetic variants affecting IQ occur in different frequencies in the populations identified? I'm not sure anyone is denying that you can divide groups up into smaller units?

No, Observer. No one is denying that you can divide populations up as much as you like. In fact, you've seen the argument that one can just as meaningfully split humanity into a thousand arbitrary groups as three.

However, these particular groups come with a legacy of slavery, colonialism, discrimination and eugenics, which makes the question "Why?" Why would you work to perpetuate the idea that those particular groupings are valid? Whose decision was it that the Irish and the French and the Slavic "races" are now folded into white, and why do you abide by it, much less rationalize it, much less continue to rationalize it after the weaknesses in your data are pointed out to you? Why do you support the industry of blaming particular groups for the continued effect of the legacy I mentioned?

Of course, Greg has been trying to get anyone to answer those questions for weeks now.

***Why would you work to perpetuate the idea that those particular groupings are valid? ***

I not saying that people should be lumped into those groupings. But as Saletan says, if people are going to use those categories to analyse outcomes then they can't avoid looking at causes of disparities. Including one's they don't like. Which is why Saletan suggests not using those categories in the first place.

Actually, Observer, you posted the clustering data as counterargument to the idea that those weren't valid groupings. So, yes, you have argued for those groupings.

Yes, I posted the clustering data to show that although those groups are social constructions that doesn't mean they are biologically meaningless.

That doesn't mean that society has to use them. People could just be viewed as individuals if that's what society wanted.

But this is the fallacy. Think about geography again. Let's say you sampled Canadians and Americans. You find a difference. You build on this difference and theorise about it and so on and someone comes along and says: "This is an arbitrary thing, this border" and you say "No, the difference is biological there fore there are two distinct groups, Canadians and Americans. It is a socialy constructed thing but there are biological consequences"

Then the UN takes over and divides North America up differnetly. The Canadian US border now runs from a point west of Hudson's Bay south to the Rio Grande. One side is Canada, the other side, the US. (Mexico is left intact). Now you get new data, Canadian and US, and you find a difference there as well. You say "Candians and Americans .. .they are biologically different" and someone says "No, that is an arbitrary division" and you say "No, these biological parameters are different in these two groups. Yes, it may be a socially constructed pair of groups, but there are biological consequences"

Then, the UN changes their mind and they .... (etc. etc. etc)

Listen carefully.

Novel alleles arise randomly across the species. Most go away, some are selected for, but the bulk of those extant are randomly distributed around their point of orign. The points of origin have no biases as to where they occur. They can occur at the border or in the middle of some "racial" or geographical division. In the absence of a persistent barrier (and those are quite rare) there will be a continuous variation across the landscape among polymorphic genes.

At any point you can divide the world into parts, utterly arbitrarily, and name the different areas "races" and you will see a group difference BECAUEAS THAT IS WHAT HAPPENS WHEN YOU ARBITRARILY DIVIDE UP MYRIAD CONTINUOUS RANDOMNLY DISTRUBUTED THINGS!!!!!!!11!!

This is not hard. Failure to understand this could be ignorance. But usually it is wilful ignorance. Usually it is racism.

Now, having said that (for the tenth time) let's seal the deal with an analogy.

Let's say that the variables we are looking at are not biological but rather, lat/long. Two variables, one giving position in space in relation to the poles, the other giving position in space in relation to the prime meridian.

We measure lat/long of many individuals in samples around the world. Each sample is taken by travling a thousand miles in a random direciton, then measuring the lat/long of the first 10,000 peopole we encounter. We do this ten times. We have ten samples.

The lat/long of these ten samples will be distinct. They will show a clear difference among these populations. These populations will be easily definable as separate "races" by the criteria that the race-model supporters are insisting on for human polymorphisms.

Observer, at #32, you post a number of responses to my earlier comment. However, in some, I think you might want to post your sources, for otherwise I think you explain too much. For example, you report induction test disqualification rates for blacks and whites. Do you have any data on when that was, and why? If the reason was intellectual deficiency, that would put the cutoff at an IQ of 71-72 for whites, so let's say 72. The 30% failure rate for blacks would give them a mean IQ of 80 on the same test (and the remaining inductees would have a median IQ of about 87). That score of 80 is rather lower than the 85 previously argued, or the 90 found in 1997 on the WAIS-III. (Sorry, I don't have data for the WAIS-IV to hand now). As we're talking the Army of Occupation, remember the soldiers were born in the 1920's - cutting those discrepancies year by year argues for a social cause,, not genetics. (50 more years, will we be at parity?)
Second, is there any data (not a caveat about possible explanations) about the selection bias in Eyferth's sample, or in similar samples? In sounds like a potential explanation, but not one that's been tested. If strongly emphasized, it argues against ever finding an effect, allowing you to hold the hypothesis despite evidence.
I don't understand what you mean by testing children before the genotypic relationship is fully manifested. Do you mean the IQs are too high? Given the relative stability of IQ after age 8, the effects would be too small to show, and anyway, we don't have parental IQ to test against, as you point out.
Again, I'd appreciate an explanation as to why the US differences don't show up on the same test when applied in Canada (for bonus points, explain why Korean children are good at fine motor coordination). Go back and look at Scarr-Salapatek's papers, for example the Science paper of 1971, on the relative contribution of genetics and environment in low and high-advantage groups.

Can I recommend, above all, the article Intelligence: Knowns and Unknowns, from American Psychologist, and easily found on the web. There's enough confounds on the topic that you can fool yourself or others very effectively. Frankly, I think halving the IQ disparity for the US in the last 50 years is a good sign that genetics aren't yet an issue. The 'gene for intelligence' seems located right next to the 'gene for alcoholism', frequently found and never replicated.

***for example, you report induction test disqualification rates for blacks and whites. Do you have any data on when that was, and why?***

That comes from p261 of the 30 year review paper by Rushton & Jensen. They refer to Loehlin et al. (1975, pp. 126â128)

"Third, there was rigorous selection based on IQ score in the U.S. Army at the time, with a rejection rate for Blacks on the preinduction Army General Classification Test of
about 30%, compared with 3% for Whites (see Davenport, 1946, Tables I and III)."

***I don't understand what you mean by testing children before the genotypic relationship is fully manifested. Do you mean the IQs are too high? Given the relative stability of IQ after age 8, the effects would be too small to show, and anyway, we don't have parental IQ to test against, as you point out.***

Here's what Rushton & Jensen say, again on p 261:

"First, the children were still very young when tested. One third of the children were between 5 and 10 years of age, and two thirds were between 10 and 13 years. As discussed in Section 5 (see Figure 3), behavior genetic studies show that while family socialization effects on IQ are often strong before puberty, after puberty they dwindle, sometimes to zero."

There's an interesting discussion of the shared environment/non-shared environment here. http://infoproc.blogspot.com/2009/11/mystery-of-nonshared-environment.h…

***(for bonus points, explain why Korean children are good at fine motor coordination***

I'd recommend Jon Entine's article 'Strawman of Race' which discusses race & sports! Entine writes:

"Where flexibility is key, East Asians shine, such as in diving and some skating and gymnastic events. Their body types tend to be small with relatively short extremities, long torsos, and a thicker layer of fat--a scaled down mixture of mesomorphic and endomorphic characteristics As a result, athletes from this region are somewhat slower and less strong than whites or blacks, but more flexible on average. "Chinese splits," a rare maneuver demanding extraordinary flexibility, has roots in this anthropometric reality. Itâs a key skill set for martial arts, which of course also are rooted in Asian traditions. Those anthropometric realities circumscribe Asian possibilities in jumping: not one Asian male or female high jumper makes the top 50 all-time. Many scientists believe this distinctive body type evolved as adaptations to harsh climes encountered by bands of Homo sapiens who migrated to Northeast Asia about 40,000 years ago. The excavation of an abundance of precise tools in Asia, including needles for sewing clothes to survive cold winters, has led scientists to speculate that Asians were "programmed" over time to be more dexterous. Studies indicate that East Asians do have the quickest reaction time, which some have speculated may play a role in Asian domination of Ping-Pong."

***The 'gene for intelligence' seems located right next to the 'gene for alcoholism', frequently found and never replicated.***

It's likely there will be hundreds of genes of small effect.

Um... am I the only one here who understands the limits of IQ tests themselves? As someone who administers them for a living, I feel a need to fill an apparent knowledge gap among commenters here. The tests are called IQ tests because of convention: they do not measure intelligence any more than they use a quotient to determine their score. A century ago, when Binet developed the first test like this, it was to determine if educating a certain segment of the population (today called Mentally Retarded, or MR) was worthwhile or not. It was basically a pass/fail model. American racists took the ball and ran with it for a while, keeping non-English-speaking immigrants from moving here, segregating the military, etc. Current tests as they exist are designed to PREDICT A PERSON'S ACHIEVEMENT IN A "TYPICAL" AMERICAN CLASSROOM. That's it. They happen to do this fairly well (though some articles this week suggest that Working Memory tests might be better, but I digress).The name IQ is essentially a marketing tool, and the companies that call their tests Cognitive Abilities Measure, or something, tend to be less successful. So the disparity in IQ among races is the same disparity of success we get from our public school system: in other words, the tests are "biased" in the same way (and roughly to the same degree) that our schools are.
Now, if our culture values certain skills (written language and mathematical and spatial ability versus musical ability, the ability to track an animal, build a house, grow food, communicate emotional information with others, etc.), then the question I want answered is, if the brain size data holds (and I am skeptical -- many racist researchers have falsified data or used falsified data sets to support their agenda), then what is the significance between brain size discrepancies and the increasing emphasis in our culture on paper-and-pencil type abilities? Are we increasingly valuing specific brain types/sizes at the expense of encouraging/maintaining these other skill sets?
The point is, Intelligence may be very difficult to define, but it is most definitely NOT IQ, and the two terms should NOT be used interchangeably, ever.

THANK YOU DocBob for saying what needed to be said in comment #1.

***Now, if our culture values certain skills (written language and mathematical and spatial ability versus musical ability, the ability to track an animal, build a house, grow food, communicate emotional information with others, etc.), then the question I want answered is, if the brain size data holds (and I am skeptical -- many racist researchers have falsified data or used falsified data sets to support their agenda), then what is the significance between brain size discrepancies and the increasing emphasis in our culture on paper-and-pencil type abilities? Are we increasingly valuing specific brain types/sizes at the expense of encouraging/maintaining these other skill sets?
The point is, Intelligence may be very difficult to define, but it is most definitely NOT IQ, and the two terms should NOT be used interchangeably, ever.

Posted by: DocBob | January 11, 2010 9:57 AM***

DocBob,

In fact it turns out that those arguing for no brain size differences, like Franz Boas & Stephen Jay Gould, were mistaken:

"The reanalysis bears on whether craniometrics, the measurement of skull shape, can validly identify ethnic origin. As such, it may prompt a re-evaluation of the definition of human races and of ancient skulls like that of Kennewick Man.

''I have used Boas's study to fight what I guess could be considered racist approaches to anthropology,'' said Dr. David Thomas, curator of anthropology at the American Museum of Natural History in New York. ''I have to say I am shocked at the findings.''

Forensic anthropologists believe that by taking some 90 measurements of a skull they can correctly assign its owner's continent of origin -- broadly speaking, its race, though many anthropologists prefer not to use that term -- with 80 percent accuracy.

Opponents of the technique, who cite Boas's data, say the technique is useless, in part because environmental influences, like nutrition or the chewiness of food, would overwhelm genetic effects.

Boas measured the heads of 13,000 European-born immigrants and their American-born children in 1909 and 1910 and reported striking effects on cranial form, depending on the length of exposure to the American environment.

But in re-examining his published data, Dr. Corey S. Sparks of Pennsylvania State University and Dr. Richard L. Jantz of the University of Tennessee find that the effects of the new environment were ''insignificant'' and that the differences between parents and children and between European- and American-born children were ''negligible in comparison to the differentiation between ethnic groups,'' they are reporting today in The Proceedings of the National Academy of Sciences."

http://www.nytimes.com/2002/10/08/science/a-new-look-at-old-data-may-di…

Also, Stephen Jay Gould's allegation that Samuel Morton had doctored his skull collection was re-investigated by John Michael. Michael found very few errors & those that were found were not in the direction Gould claimed. Michael found Gould was mistaken & that Morton's studies were conducted with integrity.

Michael JS 1988. A new look at Morton's craniological research. Current Anthropology 29: 349- 54.

In relation to your question, I think the answer is yes. Especially with improved technology making more job types redundant.

Observer, now why would you cite Sparks & Jantz and not note that in 2003, Gravlee, Bernard & Leonard looked at the data again, determined that Sparks and Jantz were incorrect in both their analysis and their characterization of Boaz's position, and applied modern statistical methods, finding that skull plasticity was actually greater than Boaz had estimated?

Gravlee, Bernard & Leonard used data published by Boas in 1928, by which timeâas was acknowledgedâsome 4,000 of the original subjects had mysteriously gone missing. Gravlee et al. say, "It would be a worthwhile project for future researchers to explain this discrepancy and locate the missing data."

They also report no general influence on child CI of time elapsed since parental immigration into the United States. This serves only to underline the likelihood that no confidence should ever have been placed by twentieth-century anthropologists and "anti-racists" in Boasâs vast but inadequate data set.

***were incorrect in both their analysis and their characterization of Boaz's position***

Yes, in fairness to Boas his claims actually seem more modest and reasonable as presented in this paper by Gravlee et al:

"The myth that the cephalic index was totally plastic and
shaped by the environment was not something that Boas
himself believedâ (Holloway 2002:14622). This assessment
of Boasâs position is borne out by his summary of the immigrant
study in The Mind of Primitive Man:
The traits of descendants of immigrants examined were
head-measurements, stature, weight and hair-color. Among
these, only stature and weight are closely related to the
rate of growth, while head-measurements and hair-color
are only slightly subjected to these influences. Differences in hair-color and head-development do not belong to the group of measurements which depend in their final values upon the physiological conditions during the period of growth. From all we know, they are primarily dependent upon heredity. [Boas 1938:93â94, emphasis added]
Third, Boas explicitly cautioned against the view that
plasticity in cranial form implies infinite malleability under changing environmental conditions. Sparks and Jantz
misrepresent both the significance of the immigrant study
and anthropologistsâ current understanding of human
biological plasticity by implying that cranial plasticity
knows no bounds: âIn America, both Blacks and Whites
have experienced significant change in cranial morphology
over the past 150 years but have not converged to a
common morphology as might be expected if environmental
plasticity plays a major roleâ (2002:14638). Even a
casual reading of Boasâs own writings should have warned
Sparks and Jantz to avoid such a claim."

http://www.anthro.fsu.edu/people/faculty/CG_pubs/gravlee03b.pdf

It makes little sense to attribute both the gap between white & black americans as well as that between africans and african-americans to genetics, because AfAm admixture just isn't that high.
http://www.gnxp.com/blog/2007/03/african-iqs.php

Did Saletan ever say he got his info from Sailer? As of right now the Sailer-Saletan connection seems like speculation.

stewart #53,

- black IQ scores drop with increasing age, growing the black-white gap to about 1.1 sd by adulthood
- average black IQ among adults was around 80 in the early 20th century and is more like 85 now, cutting the gap by about 1/3
- improvements in IQ appear to have stopped by the early 1990s and the scores appear to be remaining flat since
- all of these trends are mirrored in the NAEP long term trend scores as well
- the cause of the improvement during the 20th century is ostensibly environmental
- the cause of the remaining gap is unknown, but as pointed out in the 1996 APA study you cited, it's not due to SES alone or mere test bias

sources for these findings are the series of papers by Flynn, Dickens and Murray circa 2005/6

Influence can be defined as the power exerted over the minds and behavior of others. A power that can affect, persuade and cause changes to someone or something. In order to influence people, you first need to discover what is already influencing them. What makes them tick? What do they care about? We need some leverage to work with when weâre trying to change how people think and behave.

www.onlineuniversalwork.com

I thought it was clear, but it is speculation on my part that Sailer was a major force behind Saletan's original series; more recently, however, Saletan has indeed gone to Sailer for comment for his Slate column.

***Saletan has indeed gone to Sailer for comment for his Slate column.***

You mean gone to him in the sense of quoting comments from his site. He hasn't gone to him and asked Sailer to comment.

What is very interesting to me in the Gravlee et al reanalysis is that there seems to be an effect of latitude of origin on the direction of the change of the cephalic index on moving to NYC (40° 47') . Those from regions south of NYC (Sicily, cap Palermo, 38° 13') have their cephalic index go up, those from north of NYC (Scotland, Aberdeen, 57° 9'), have it go down. The change for Hebrews doesn't fit this, but then the latitude of origin of that group of people is not clear.

My suspicion is that this is a direct environmental effect due to latitude and light exposure and its effects on nitric oxide. There are photochemical reactions in the skin that are involved with NO physiology. Precisely how and in what way are not well known. Nitric oxide from UV stimulated keratinocytes does trigger the increased production of melanin by melanocytes. I like an photochemical NO explanation for variation of skin color with latitude better than a vitamin D explanation.

It turns out that NO is also what regulates neurogenesis, with low NO causing neuronal hyperplasia. Low NO causing neuronal hyperplasia is important to me in my research on autism, I think that is the mechanism for the larger brains of people on the autism spectrum.

Low NO from less sunlight and also from less NO/NOx from the bacteria I am working with would explain the gradient of brain size with latitude that Greg mentioned. More NO at lower latitudes would cause smaller brains purely through developmental effects. The reduced size of female brains is also explained by NO because the estrogen receptor activates nitric oxide synthase and results in a higher basal NO level in women. It is thought that this higher NO is what protects premenopausal women from heart disease. I think this higher NO from estrogen is also responsible for the male excess in autism (not testosterone, but NO does inhibit testosterone synthesis, so low NO causes high testosterone (which stimulates growth of hair, expanding the niche for my bacteria)).

How this affects intelligence is not clear. What is important in âintelligenceâ has to include (pretty obviously) how much cognitive power can be brought to bear while thinking about a problem. This does not include the whole brain. There is not sufficient metabolic capacity for every neuron in the brain to fire simultaneously even if the regulation of the brain allowed that to happen. That is a seizure, and there are multiple protective mechanisms to keep that from happening (including pruning cells during a seizure).

The functional connectivity in the brain is also regulated by NO (my hypothesis but pretty clearly it has to be). I think the computational power of a particular part of neuronal tissue depends on how big that particular piece is (probably minor importance), how it is actually connected (via axons and synapses and stuff) (somewhat more important) and how it is functionally connected (via NO signaling) (the actual determinater). Some of this is determined in utero by actual proliferation of neurons but also by epigenetic programming of those neurons which determines their NO sensitivity. The detailed actual connections are formed through Hebbian remodeling (which is regulated by NO).

Latitude is not the only thing that affects NO status (it is probably a relatively minor thing), social stress and other stress affects it a lot too. High social stress causes acute low NO (this is probably the biggest thing). This is probably one of the mechanisms for stereotype threat, and likely has both prompt and long term effects. Exposure to stress in utero does increase brain size in animals, likely it does in humans. Exposure to stress in utero does increase incidence of autism. It likely also epigenetically programs the brain to generate less NO. Exposure to social isolation does program the brain to produce less NO in rodents. I think this happens in PTSD too, programming for lower NO makes the brain more sensitive to low NO, and allows it to enter the low NO state (i.e. the fight or flight state) more easily and more rapidly, as in hypervigilance.

That there is a gradient of head size with latitude, but there is no âracialâ gradient with latitude, implies that what ever regulates head size is modulated by latitude. A NO/NOx mediated via light hypothesis might also explain some of the increased incidence of heart disease, hypertension and diabetes among people of color. Low NO from light is additive to low NO from social stress.

I just realized, the difference in brain size between men and women can't be due to differential genetics because the only difference is that males have an extra Y chromosome and women don't. In XY individuals with androgen insensitivity, there isn't even that difference.

Darwin also touched upon these racial differences in cranial capacity. They are well established. As far as indigenous populations, the Australian Aborigine has a smaller brain size than the African, and Native Americans have larger brains than Europeans.

The differences in measured IQ generally seem to be correlated with cranial capacity. Rushton posits that the r/K selection theory came into play in creating these differences, and that they count for the historic disparities in cultural development among various populations.

This is a very offensive idea, but to me also an intriguing theory. If he were talking about say, breeds of dogs, no one would be offended, but this is PEOPLE. I think we should remember that the differences are small, the ranges in intelligence AND brain size will often overlap, and none of this can be fairly used to create policy or judge individual people.

Another fact Rushton does not touch upon in his work is that women have bigger brains in relation to their body size than men, and although they develop faster and stop growing sooner, they score higher than men on IQ tests. This holds for all races. I don't know what that says about cultural development... hm.

We should also remember that there are a lot of dumb white folk out there who can't spell that use Rushton's work as justification for their hatred.

"Rushton accounts for this by making the specific claim that Africans and non-Africans split from each other about 200,000 years ago, and that it is likely that evolution is a progressive process with change happening in the direction, long term, of a particular ideal of "advancement." Specifically, Whites are more evolved in the 'advanced' direction while Africans remain primitive. "

Can you back of this statement with a citation? As with every other scientifically literate person, Rhuston argues about differntial adaptation. Which is value neutral. 'Advancement' and 'ideal' are Idiosyncric values, the nature of which develops in relation to the bioculture of an ethnos. Refer: Rushton and Jensen, 2005. Wanted: More Race Realism, Less Moralistic Fallacy.

I don't think citation means what you think it means. This blog post reports the cited source.

Greg,

I am familiar with the book. Again, Rhuston discusses differntial adaptation. That means different not better. The former is a scientific claim, the later a value-laden one. Teleological evolution -- the sense in which you can speak of 'progress' and 'being better' and 'moving towards something' is a 19th century idea based on the something akin to Herbert Spencer's progressive philosophy. Perhaps I missed where Rhuston argues a progressive evolutionary philosophy. So I was asking for a citation. The book you refer to does not discuss this. But maybe he did in the 80's or some other time.

I paraphrased the cited source accurately. Your beef is with Rushton, not me.

I question your implicaiton that Rushton either has a handle on how evolution works, how human evolution has worked out historically, and especially, that he is not explicitly stating that there are different levels of "progress" in his "races." To suggest what you are suggesting is to be very much in denial.

And I should let you know right away that I'm not interested in playing the game where we pretend we are having some kind of conversion and during that period of time you load your racist bullshit into a series of comments on my blog. You have your own blog. Don't use mine. Not that I'm sure you were going to, but that is the usual pattern.

If, however, you post something on your own blog regarding what I'm saying over here, you are more than welcome to ping us and let us know! Maybe we can get an interbloggal conversation going.

"If, however, you post something on your own blog regarding what I'm saying over here, you are more than welcome to ping us and let us know!"

Done.

I'm not up on the research regarding this topic. But as I read some of the discussion I was wondering: do we know if "IQ" appears to be inheritable? I.e.: are "smart" parents more likely to have "smart" kids?

Smart parents tend to have smart kids. Parents who speak English have kids who speak English. Parents who fish or hunt have kids who fish and hunt. Kids tend to have a similar income to their parents, similar education level, and so on.

If, when you say "inheritable" you mean "genetic" the simple fact that children tend to resemble their parents does not demonstrate that link.

The way people often end up thinking about these things is this: The less we know about the mechanism of children resembling the parents, the more we attribute that to genes, regardless of the actual material evidence for a genetic connection.

Then you look for the genes, and if you don't find them, rather than simply saying "well, maybe it's not genetic" you start to come up with some rather interesting models for how it can still be genetic even though a search for actual genes that cause the observed variation has failed again and again.

Along the way, people who really want the thing they are studying (like, for instance, intelligence) to be genetic say things in the papers they write like "It is presumed to be genetic" and after a decade of that people site those earlier papers and say "several papers have indicated that it is genetic" and after a decade of that people start to write in their papers that fail to find clear eveidence of a genetic connection things like "a vast literautre supports the idea tht this is genetic so our inability to see this must be because ... [fill in the latest model for why the genes are invisible].

And if you say things like I just said, people say to you things like "your ruining science" or "you just need to come to terms with the truth" or "you have a political bias" or "show me the definitive prove of the abcence of this thing I can't show you because we don't know what it is" and so on and so forth.

And then, if someone like me suggests that maybe those who seem to really really need a gene that makes, typically, peole of dark skin seem inferior to them racist, which I do occasionally do, they say things like "erase where you said that or I'm going to sue you!!!11!! You'll be hearing from my lawers!!!11!!

To which I say, "have your lawyer contact me at his or her earliest opportunity"

And then after that, nothing. Just a void where there used to be a raging angry white male.

Greg,

How did you want to set up this interblog? I was reading through the comments and they are pretty ill informed. Even at Huff Post, where I post on this issue, people are more informed.

You might like a site called "Liberal Biorealism." There are a lot of ways you could see this. Just as you define types of 'racism' as bad, you can define interpretations as such. I checked over Rhuston and I may have made a rash accusation. I will email him when I get a chance to get a clarification.

Regardless, we will know for sure within a couple of years. So, if so, people will adjust around it. If not, no point in arguing otherwise.

Lesacre

The way this works is that I pwn you in a blog post when I get the time to do so. I don't think you'll have to wait long.

Your opinion about the comments here is interesting, given that you write about racial issues and have never heard of Rushton. You're like some guy who has a new TOE but has never heard of ... no, wait, I don't want to make an equivalence between Rushton and anyone smart. Forget it.

Anyway, there will be a post.

"Your opinion about the comments here is interesting, given that you write about racial issues and have never heard of Rushton."

That's not what I said. I have read over Jenson and his papers (within the last 10 years) on group differences in intelligence. And he is not the only one that comments on this. But I have read though his views on life- history. The former fits into his Life History model, but is independent of it. I can posit that the performance advantage of Ashk Jews, relative to Hispanics has a partial genetic etiology without implying that, on average the former group has, on average, smaller tools. I would note that Saleton in his Slate article made a similiar mistake.

Regarless, Touché.

I do find it odd, that you seem to agree with the idea that:

"Intelligence is said to be the hallmark of the human species .. and that [if there are differences, it implies] it is likely that evolution is a progressive process with change happening in the direction, long term, of a particular ideal of "advancement"

Or maybe you could clarify your position or link to a post in which you have -- as the same logic would apply to individuals, with some fitting the hallmark and representing more "advanced" members of the species -- if it could be shown that their intellectual advantage had a partial genetic etiology.

A statement like "Intelligence is said to be the hallmark" is not an agreement, it is a statement.

What if I said: "It is said that the Boston Red Sox have a curse on them."?

Does that imply that I believe in curses?

Greg,

(Don't bother posting)

I updated my outline of the hereditarian hypothesis in case you're still interested. Generally, I find that the evidence supports it more than the environmental hypothesis. I've been emailing around to try to get the hypothesis dispositively tested with the help of modern genotyping -- but there seems to be some reluctance to doing so. Anyways, if your interested:

"Race, genes, and disparity"
http://abc102.wordpress.com/