IQ Won't Make You Rich : The Frontal Cortex

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Jonah Lehrer is a contributing editor at Wired. He's also written for The New Yorker, Seed, Nature, the Boston Globe and is a contributor to Radio Lab. He's the author of Proust Was A Neuroscientist. His new book is How We Decide.

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IQ Won't Make You Rich

Posted on: November 27, 2007 9:21 AM, by Jonah Lehrer

From Brad DeLong:

If inherited genetically-based IQ were the source of the extra edge that the children of the rich get in our society, than we would expect a parent with 4 times average lifetime full-time earnings--say $200,000 a year--to have a kid with a lifetime average income of $51,500 instead of the average of $50,000. But it is not $51,500. It is $150,000.

Our obsession with the IQ test seems to exploit what I'll call the quantification bias, which is the fact that being able to quantify something makes it seem more important than it really is. And so we fixate on IQ scores in such a wide variety of debates, from race to inequality, because it's such a neat numerical score, even though it's relevance to these debates (as DeLong points out) is not always clear. But it's easier to argue about a quantifiable variable (that's partly innate) than it is to focus on the real sources of inequality, like substandard schools.

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Comments (25)

The other day I had two of my children in the kitchen. My daughter has a below average IQ and goes to special ed at school. My son has a high IQ that qualifies him for HG (highly gifted) programs at school. My daughter said she heard from a girl on the playground that the HG kids were smart and the special ed kids were dumb. (Gotta love that playground.) I told her what I truly believe - IQ tells you what the possibilities are - level of effort tells you what the probabilities are. Unfortunately I'm afraid my words were dismissed because ability and effort sometimes fall short of that trump card - self esteem...

Posted by: amybuilds | November 27, 2007 2:53 PM

"Unfortunately I'm afraid my words were dismissed because ability and effort sometimes fall short of that trump card - self esteem..."

And that's where you come in, Mom.

Posted by: alice | November 27, 2007 7:59 PM

But it's easier to argue about a quantifiable variable (that's partly innate) than it is to focus on the real sources of inequality, like substandard schools.

Translation: I know nothing about sociology, economics, psychology, etc, but I'll pretend like I do anyway.

You are misreading even the evidence presented by DeLong. If IQ seems to be pretty unimportant in that post, so much the worse for any other variable you can name, because IQ is still the most important one.

"Substandard schools" is utter nonsense. It's a platitude that contradicts all evidence.

Posted by: Gray Dave | November 27, 2007 9:56 PM

The vast majority of variation in both attained class and class mobility is not accounted for by IQ... Nonetheless, intelligence is the strongest single factor causing class mobility in contemporary societies that has been identified.

http://www.staff.ncl.ac.uk/daniel.nettle/britishjournalpsychology.pdf

Posted by: Gray Dave | November 27, 2007 11:10 PM

"Our obsession with the IQ test seems to exploit what I'll call the quantification bias, which is the fact that being able to quantify something makes it seem more important than it really is. "

Let's discuss the more interesting obsession among intellectuals to discredit IQ, despite it's overwhelming success as a social science tool. (paired with obsessions over long discredited variables such as "substandard schooling" or parental income)

I'll call this reality bias, which is the fact that demonstrable reality (such as ethnic gaps in intelligence) discredits almost every conviction the dominant intellectual elite bases its fragile worldview on. This causes intellectuals to use any available argument they happen to stumble upon against ideas they dislike, but have never studied.

Posted by: Gray Dave | November 27, 2007 11:23 PM

This reminds me of the debates which went on after James Watson committed his faux paus, recently.

"obsession among intellectuals to discredit IQ, despite it's overwhelming success as a social science tool."

Yes, I suppose there may be an obsession to discredit IQ, which would be wholly defensible,... after all science does march on. But please tell me where IQ has been used as a social science tool with great success. I guess you'd also need to define success while you're at it.

"But it's easier to argue about a quantifiable variable (that's partly innate) than it is to focus on the real sources of inequality, like substandard schools."

See now Jonah, that's a tell and you can now be labeled as a liberal and attacked for your Utopian views as Gray has done.

But I will agree that you may have overstated the point that substandard schools are the real source of inequality as opposed to IQ or intelligence.

Posted by: alice | November 28, 2007 10:29 AM

. But please tell me where IQ has been used as a social science tool with great success. I guess you'd also need to define success while you're at it.

Success relative to all other social science variables. See quote above. It is the single best predictor of economic outcomes. Single best predictor of academic outcomes. Single best predictor of job performance. Emerging evidence suggests the same for health outcomes as well as national development.

Yes, I suppose there may be an obsession to discredit IQ, which would be wholly defensible,... after all science does march on

No, I wasn't talking about among researchers, that would be fine (and to the extent this has been the case, they have ended up proving the opposite of what they intended) but an obesession among the chattering classes who don't know the science, but nevertheless habitually use whatever club they happen to stumble upon to attack an idea they know little about, but find utterly distasteful. It is completely antiscientific, and yet even science writers like Mr. Lehrer above have no shame in delivering lies like "But it's easier to argue about [IQ] than it is to focus on the real sources of inequality, like substandard schools.", because lies about IQ are approved by the intellectual community which overwhelmingly shares an ideological outlook which finds IQ incongenial.

Posted by: Gray Dave | November 28, 2007 4:16 PM

Gray Dave, you overlook the possibility that measured IQ is, itself, an effect rather than a cause of socioeconomic status.

Evidence from a variety of studies suggests that in middle-class or above households, with decent nutrition and family stability, "native intelligence" (whatever that might be) is largely genetic and a good predictor of success. However, in poverty level and unstable households, measures of nutrition, family stability, undisturbed sleep, and expectation of reward for work is the best predictor of both childhood IQ and adult success, with any variation in genetics insignificant and drowned out by other effects. This implies that IQ as measurable by tests requires an environment.

There is an awful lot of good research into this, actually.

Besides:
"Nothing in this world can take the place of persistence. Talent will not; nothing is more common than unsuccessful people with talent. Genius will not; un-rewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent." - Calvin Coolidge

Posted by: Luna_the_cat | November 28, 2007 4:28 PM

I don�t think anyone really wants to discredit IQ as much as we all want to emphasize that it�s not a holistic measure. IQ alone doesn�t do the trick, there has to be other pieces woven into the puzzle. There is a study involving Romanian orphans that showed children, who had lived in severely deprived conditions, had below average IQ tests when they were first adopted by middle class English families. Years later, after living in much improved conditions, these same children tested higher in IQ tests. I think this points to the basic premise behind Maslow�s hierarchy of needs. Environment played a role for these kids. That being said I also think there are limitations, my guess is that after a person�s basic needs are met, greater improvement to a person�s environment probably doesn�t dramatically impact IQ. It is what it is. And yet I would go further to say that the economic status that anyone enjoys (when accompanied by intelligence rather than say a pro-football career) is likely due to environment. Look past the IQ and thank the parents and the teachers.

Posted by: amybuilds | November 28, 2007 6:23 PM

Gray Dave,(is Gray your name or an adjective?)

Thank you for your definition of a successful tool in this case, that of being a predictor. So what we are talking about is statistical analysis.

But you are not saying that the knowledge about IQ correlations is a useful tool is forming social policy of any kind.

So it's an interesting fact....

And an amazingly potent emotional issue.

Maybe someone should do a study on why that is.

Perhaps what people are drawn to is what they can actually do something about, like inadequate schools, rather than wringing their hands about things they have no control over like IQ's. Couple that with the image of Margaret Sanger socially engineering the master race and the stomach begins to turn.

These guys have some pretty interesting research results they are trying to publish.
http://freakonomics.blogs.nytimes.com/2007/10/19/james-watson-black-intelligence-and-new-research-by-fryer-and-levitt/

Posted by: alice | November 28, 2007 9:17 PM

Gray Dave, you overlook the possibility that measured IQ is, itself, an effect rather than a cause of socioeconomic status.

No, this is what adoption and kinship studies have already tested. Socioeconomic status has no detectable influence on IQ, or much else, when you control for genes.

my guess is that after a person�s basic needs are met, greater improvement to a person�s environment probably doesn�t dramatically impact IQ. It is what it is

Correct. Bad environments can stunt normal development, but good environments don't improve your lot.

And yet I would go further to say that the economic status that anyone enjoys (when accompanied by intelligence rather than say a pro-football career) is likely due to environment. Look past the IQ and thank the parents and the teachers.

Nope. Parents and teachers don't do a thing.

http://www.marginalrevolution.com/marginalrevolution/2004/11/nature_nurture_.html

The environment is very important, just not the environment you expected.

Posted by: Gray Dave | November 29, 2007 2:06 PM

No, this is what adoption and kinship studies have already tested. Socioeconomic status has no detectable influence on IQ, or much else, when you control for genes.

Flatly untrue. The references are on my other computer, and rather than waste time now I will post them tomorrow, but this is either a sign of deep ignorance of the state of the field or a deliberate lie; either is unabmirable.

In the mean time, I strongly suggest you read this:
http://www.lrainc.com/swtaboo/taboos/apa_01.html
--although it is now several years old, it is an excellent summary of research, all of it referenced, and mentions a number of key points. I would particularly like to draw your attention to sections IV and V, especially the section labelled "Interventions":

Children who participate in "Head Start" and similar programs are exposed to various school-related materials and experiences for one or two years. Their test scores often go up during the course of the program, but these gains fade with time. By the end of elementary school, there are usually no significant I9 or achievement-test differences between children who have been in such programs and controls who have not. There may, however, be other differences. Follow-up studies suggest that children who participated in such programs as preschoolers are less likely to be assigned to special education, less likely to be held back in grade, and more likely to finish high school than matched controls (Consortium for Longitudinal Studies, 1983; Darlington, 1986; but see Locurto, 1991).

More extensive interventions might be expected to produce larger and more lasting effects, but few such programs have been evaluated systematically. One of the more successful is the Carolina Abecedarian Project (Campbell & Ramey, 1994), which provided a group of children with enriched environments from early infancy through preschool and also maintained appropriate controls. The test scores of the enrichment-group children were already higher than those of controls at age two; they were still some five points higher at age twelve, seven years after the end of the intervention. Importantly, the enrichment group also outperformed the controls in academic achievement.

and one particular sentence under the "Individual Life Experiences" heading:

Although the environmental variables that produce large differences in intelligence are not yet well understood, genetic studies assure us that they exist. With a heritability well below 1.00, IQ must be subject to substantial environmental influences.

...and further down, the discussion of more complex, group-based social effects, such as the effect of being in a caste-like minority:

Ogbu (1978) argues that the children of caste-like minorities do not have "effort optimism," i.e., the conviction that hard work (especially hard schoolwork) and serious commitment on their part will actually be rewarded. As a result they ignore or reject the forms of learning that are offered in school. Indeed they may practice a sort of cultural inversion, deliberately rejecting certain behaviors (such as academic achievement or other forms of "acting white") that are seen as characteristic of the dominant group.

The science is not settled, done and dusted, but your assertion that environmental variables don't account for variance of measurable IQ "when you control for genes" is already known to be complete nonsense.

Posted by: Luna_the_cat | November 29, 2007 2:24 PM

Re Gray Dave's quoted material in the post above ("The vast majority of variation in both attained class and class mobility is not accounted for by IQ... Nonetheless, intelligence is the strongest single factor causing class mobility in contemporary societies that has been identified.")

Notice that it commits the age-old error of conflating IQ with intelligence. When someone comes up with a non-circular way of proving that IQ "measures" intelligence, then maybe I will sit up and pay attention. But honestly, we're no further along than de Broca was when he measured and weighed skulls by filling them with mustard seeds and then announced that men are more intelligent than women because their brains are bigger and weigh more. He just forgot to provide a link between brain size/weight and intelligence. So, Gray Dave, what is the link between IQ and intelligence?
For a fascinating history of our attempts to define and measure intelligence, and the uses to which it has been put, read the late Stephen J. Gould's The Mismeasure of Man. An oldie but a goodie.

Posted by: peggy | November 29, 2007 2:49 PM

From Gray Dave

"Nope. Parents and teachers don't do a thing.

http://www.marginalrevolution.com/marginalrevolution/2004/11/nature_nurture_.html

The environment is very important, just not the environment you expected."

Sigh (long and heavy sigh)
Adopted children - this is a group you shouldn't do studies on and expect to get straight results. Plucking a child out of one environment and putting them down in another environment and somehow expecting to be able to compare them to the biological children of the same family is sheer folly. All of these studies are flawed because you can't normalize for the extreme psychological trauma involved with abandonment and adoption - much less cross cultural adoption.

To compare the financial success of cross culturally adopted children with biological children of a family doesn't tell you much about environmental affects on IQ but it does tell you a lot about ravaging affects of abandonment.

Adoption is a good solution to a horrible problem. What do you do with a child whose parents are gone? The minute they are abandoned, for whatever the reason, these children have taken a huge hit that no environment (even Angelina Jolie's wonderful world) is going to ever satisfactorily fix.

Posted by: amybuilds | November 29, 2007 3:13 PM

Amybuilds says this:
"And yet I would go further to say that the economic status that anyone enjoys (when accompanied by intelligence rather than say a pro-football career) is likely due to environment. Look past the IQ and thank the parents and the teachers."

And Gray Dave says this:
�Nope. Parents and teachers don't do a thing.�

It seems, Gray Dave, that you are stepping beyond your original thesis that IQ is the most reliable predictor of economic success to saying that environment has no effect on economic success.

To which I say��HMMMMM, what study has shown that?�

Posted by: alice | November 29, 2007 3:51 PM

Amy,
It looks like you read the article Dave referenced.

It says that the thing which it unique to biological parents and children as opposed to adoptive parents and children is genes.

Well, along with genes comes a whole boatload of behavioral issues like investment. Biological parents tend to naturally care more for their flesh and blood than those who don't bear their genes.

I think I'm beginning to understand that IQ is indeed a lot easier to quantify than environmental factors, but not so much, if at all, more important. In fact, I wonder if any study can adequately be devised to account for all the variables present.

Posted by: alice | November 29, 2007 4:11 PM

Um, adoptive parents CAN make a big difference to a traumatised child. I've seen it done.

Having said that, I think people should read the study itself, not that miserable piece of oversimplified misreporting that Gray links to. It's available at http://www.vanderbilt.edu/econ/sempapers/Sacerdote.pdf .

The complicating factors are immense, but it certainly does not rule out environmental factors affecting outcome!

Posted by: Luna_the_cat | November 29, 2007 4:12 PM

Thanks for the link, Luna.

I can't wait to dive into those 51 pages which I'm sure are chock full of statistics and mathematical formulations which I will little be able to comprehend or dispute.

But I will read it (in the morning, with a cup of coffee)because I think that in order to hold an opinion one needs to be able to back it up or at least be familiar with the arguments.

Posted by: alice | November 29, 2007 5:46 PM

I thought this was a fair and thorough summary of the state of the science on race, IQ and all those other thorny related questions:
http://theamericanscene.com/2007/11/27/wheres-the-beef

Posted by: Jonah | November 29, 2007 5:54 PM

Two cups of coffee, maybe?

Well, I can sum up one particularly relevant point. The largest influencing factor on whether or not a child, adopted or not, went to university was:
[drum roll please]
How many children there were in the family. The bigger the family, the less likely that the adopted children would go to college. This correspondence outweighed any other.

That sounds like an environmental thing, to me. That and, with limited resources to fund higher education, it was more likely spent on biological children than adoptees.

@Jonah -- that's a good summary. Thanks for that link.

Posted by: Luna_the_cat | November 29, 2007 6:27 PM

Hey Peggy,

I finally got around to reading your post. If you read the link Jonah gave, you will find another in agreement with what you said.

Stephen Jay Gould, the Marxist liberal?

I started on this journey of learning about cognitive science and evolutionary psychology about seven years ago. My first read was Stephen Pinker, a fine writer. In "The Blank Slate" he pretty much discredits Gould off the map, accuses him of being a fan of "tabula rasa", etc. So I pretty much believed him and thought of Gould as a charlatan.

I've since learned to read everything, by everybody.

What fun! and to top it off, Gould addresses the "tabula rasa" accusation right up front.

"The straw man set up to caricature biological determinism is cultural determinism or tabula rasa in it's pure form. Although biological determinists often like to intimate, for rhetorical effect, that their opponenets hold such a view, no serious student of human behavior denies the potent influence of evolved biology upon our cultural lives. Our struggle is to figure out how biology affects us, not whether it does."

These guys are all arguing with each other.

And it's a great dialogue.

Posted by: alice | November 29, 2007 7:04 PM

but your assertion that environmental variables don't account for variance of measurable IQ "when you control for genes" is already known to be complete nonsense.

Except this is not what I said. Look again because I flatly said the opposite: "The environment is very important, just not the environment you expected."

All of these studies are flawed because you can't normalize for the extreme psychological trauma involved with abandonment and adoption - much less cross cultural adoption.

Adopted children do no worse in life than average children, and suffer no "trauma". If we look at the IQs or adult income of adopted people they are no lower than average, and have the same full amount of variation as nonadopted people. But unlike nonadopted people this variation is not correlated with the family environments they experience. In other words the correlations we see within biological families are caused by shared genes, not by shared environments. Twin and kinship studies give the exact same results.

It seems, Gray Dave, that you are stepping beyond your original thesis that IQ is the most reliable predictor of economic success to saying that environment has no effect on economic success. To which I say��HMMMMM, what study has shown that?�

Again I did not say that. 'Shared family environment' is not the same as 'environment'. amybuilds said economic status can likely be attributed to parents instead of IQ. I linked a study that powerfully contradicts this; economic status isn't related to family environments at all. It is consistent with all other studies that methodologically control for genetics.

Posted by: Gray Dave | November 30, 2007 12:41 AM

Thanks, Alice, for directing me to Jonah's link. The complexity of the issue is laid out and discussed there with great clarity. To simplify, and this is something Gould pointed out eons ago (I used the book in an undergraduate philosophy of science class I co-taught in the mid-80s), one of the many problems with trying to determine the existence of a genetic basis for intelligence (quite apart from the conflation of IQ, IQ test performance and intelligence) is that it turns out there is more genetic variation within "races" (a very slippery term anyway, as Grould noted)is far greater than that between races. I'm not a geneticist or even a scientist, so I'll say no more, but intuitively this makes sense.
One more issue Gould discussed--which is of great importance and which often gets lost in the heated debate about intelligence and IQ--is the whole history of IQ testing. The test was initially developed to identify children with learning disabilities and ensure they received adapted training within the educational system, but was quickly picked up and misused by people with other intentions (i.e., to measure intelligence, justify inequalities, prove that certain "races" were inferior intellectually, keep immigrants out of this country, justify eugenics and the neutering of the "mentally deficient", etc.).
What amazes me is (i) the longevity and recurrence of this issue, (ii) how bitterly it divides people, and (ii) the fact that Jonah's initial comment about substandard schools was immediately ridiculed and dismissed. I left the US for 25 years, and have returned to a country where people seem to accept substandard education (or deny it exists or metters)for those who can't spend a fortune on private schooling. I have even heard some of the privileged few, who send their kids to private schools, justify voting down every school bond issue put before them by saying that throwing money at the problem won't help. If that is true, then why are they willing to throw thousands of dollars a year at the private schools to educate their children (and ensure an airtight socio-economic filter to keep the "bad influences" out)?
If this analysis exposes me to the charge of being a "Marxist," then I'm in good company. Having not followed this debate for many years, I was amused to learn that Stephen J. Gould was branded as one for writing a factual history and well-argued criticism of attempts to measure intelligence.
When will we ever learn?

Posted by: peggy | November 30, 2007 11:54 AM

If I implied in my post that adoptive parents can't make a difference in a child's life then I apologize for that was not my intent. I believe adoptive parents do great things for their children and in most cases those parents greatly improve the outcomes for the child.

Also, from Alice, "Biological parents tend to naturally care more for their flesh and blood than those who don't bear their genes." I might argue with the phrasing of this. I think that biological parents experience a more complete connection with their biological children over their adopted children and this connectedness will benefit the biological child.

I guess I've just not read the same studies that Gary Dave has read. Most of what I have read indicates that adopted children tend to have higher levels of psychological issues, behavior problems, learning disabilities, and so on. I'm sure there are both genetic and environmental reasons for this.

My beliefs, based on my experiences, are that the system is designed so that the biological parents raise their biological children and when you disrupt that system, well, results may vary.

Luna - thanks for the link, I will look forward to plowing through the full study. (over a BIG cup of hot chocolate)

Jonah - thanks for the link, I will enjoy reading this as well

Alice - self esteem - that IS where Mom comes in isn't it? If only that were as easy as the day job. :)

Gary - thanks for the argument, I always find a good debate helps me expand my thinking.

Posted by: amybuilds | November 30, 2007 12:36 PM

Good comments all, and I continue to wonder why we are all so interested in this issue. There is something compelling about it.

But, foremost I wonder what good it does to study IQ.
So far I have not seen the use of it in practical terms. We all know some people are smarter than others, some people are smarter about some things and less smart about other things and I assume we all believe that intelligence is heritable....and we kinda know that intuitively.

It seems to me to be more of a game to see who can devise the most flawless study. And what in the end will it really prove? And what will we do with the information?

Posted by: alice | December 1, 2007 2:46 AM