Monday, October 22, 2007

How we think about Race and Intelligence

Media articles and the blogosphere has been abuzz about James Watson's latest indiscretion, stating that Africans are less intellectually endowed than people of European descent. He has been rightly chastised for his really insensitive and unsubstantiated remarks, but that made me think about some other articles and reports about race and intelligence and our reaction to it.

In his book, Guns Germs and Steel, Jared Diamond stresses the genetic equality of humans and explains why Europeans got a head start in achieving technological prowess, leading to their military domination over other cultures. The reasons are to be found in unique combinations of geography, climate, availability of plants that could be cultivated and animals that could be domesticated. Diamond is so mortified about starting a controversy related to group differences that he stays away from even exploring whether culture and religion could have played a role. But here is what he has to say about New Guineans " That is, natural selection promoting genes for intelligence has probably been far more ruthless in New Guinea than in more densely populated, politically more complex societies, where natural selection for body chemistry was instead more potent......That is in mental ability New Guineans are probably genetically superior to Westerners, and they surely are superior in escaping the devastating developmental disadvantages under which most children in industrialized societies now grow up". So, Diamond has no problems accepting that in principle evolution can make one group more intelligent that some other group. Not only that but according to him, at least as far as child rearing goes, New Guinean culture is superior to Western culture. Why was this not met with accusations of racism? Was it because New Guineans and other hunter gatherer societies have been persecuted and any suggestion that they could actually be more intelligent than industrialized people make us feel a little less guilty? Is it okay to say that traditional hunter gather societies are more intelligent than urban societies but not the other way around?

A 2006 study on European Jews (Ashkenazim) settled in the U.S. by Gregory Cochran, Jason Hardy, and Henry Harpending proposed that the high average IQ shown by this group resulted due to occupational constraints imposed on Jews in Medieval times. Jews were forced into trades that required computational skills such as trading and money-lending. This resulted in selection for verbal and mathematical intelligence. A follow up study by David, H. and Lynn, R. compared IQ's of European Jews with Oriental Jews in Israel and found that European Jews have an IQ 14 points higher than Oriental Jews. This according to the authors supported the earlier evolutionary explanation, since Oriental Jews "were permitted to engage in a much wider range of occupations and hence did not come under the selection pressure to develop the high verbal and mathematical intelligence that was present for Ashkenazim". Both the original study and the follow up have received attention and criticism but no howls of protests for example from Oriental Jews or for that matter any other community that they have been racially targeted.

We readily accept that we are more intelligent than our remote ancestors living say a few hundred thousand years ago. That would mean our cognitive evolution was being fueled by selection on existing variability in genes for intelligence. Would there not be such variability in modern populations and did conditions exist in the recent past such that there are discrete differences between groups? Is it even legitimate to research whether groups differ in their intellectual capabilities? In a hysterical editorial the Times of India doesn't think so. They say that some topics such as group differences are best left to sociologists (now that should solve all our problems). According to the Times the job of a scientist is to observe, test and report, which to me is exactly what Cochran et. al. did in their study of Ashkenazim Jews. Their hypothesis has not yet been validated, but there is a clear test available. This will be based on a comparison of IQ's of sibling pairs (to control for environmental differences), one of whom carries the genes that Cochran et. al. have identified as the candidate "intelligence gene" and the other who is a non-carrier. If the carrier is not smarter than the non-carrier, then the hypothesis is wrong. To date, no such specific hypothesis has been presented about innate differences in cognitive abilities between Africans and Europeans. It is reasonable to suppose that any differences are due to social and other environmental factors and the genetic component to the differences measured is negligible. But with the explosion in human genomic data the day might come when someone does present a genetic explanation. Will we be mature enough to let science do the talking?


  1. Suvrat:

    You got it wrong this time.

    Culture and religion can definitely have an impact on IQ through natural selection. However, the point is on what time scale? A million years? Definitely, yes. Ten thousand years? Not, at all. Natural selection does not operate on that time scale. Culture and religion as we know today, have been with us only on the scale of thousands of years. Anyone who suggests that within this time frame, they could make evolutionary impact, need not be taken seriously.

    If Watson argues that African culture impacts IQ on lower side through nurture, I can understand. It happens all the time. A child who does not get educational opportunity is usually less informed than an educated child. However, if his argument is that African culture has impacted genes of African people to deliver less intelligent children, then burden of proof lies on him.

  2. Survat,

    One of the problems is, how do you measure or test "intelligence" objectively. In fact, how does one even define "intelligence"? Is there a clear definition within the scientific community? IMO, I don't think so.

    Remember that IQ tests do not measure intelligence and were never meant to.

    Also, even if some test to "put a number" for "intelligence" exists, and there is an observable difference between the numerical value for two groups, how does one attribute this difference to genetic factors alone? How does one know that it's not due to environmental variables like economics, language, lifestyle, culture, nutrition, even weather, etc (You see? There are an many variables which can overshadow genetic influences to "get a number" for the supposed "intelligence" tests). So, it's going to be extremely hard to perform a controlled test to determine the contribution of genetic factors, because one don't know what all the control variables are!

  3. Abhilash-

    The topic of culture and religion in this context came up as I was trying to point out that Jared Diamond did not want to get into controversies over whether certain local cultural or religious thinking gave one society an advantage over another in inventing technology etc. He wanted to stress genetic and cultural equality, but then ends up saying New Guineans may be genetically and culturally superior to the West. Isn't that racism? That is the point of my post. Why are there different standards?

    You say " Ten thousand years? Not, at all. Natural selection does not operate on that time scale."

    You underestimate the power of natural selection. There are plenty of examples of human evolution through natural selection in the last few thousand years. Beginning the way we look, resistance to diseases (sickle cell genes), lactose tolerance genes ( a good example of how cultural practices can set up selection pressures for genetic evolution).

    Regarding Watson, I don't think he meant African culture impacted genes. But I agree with you. The burden of proof is on him.


    Again, I don't disagree that environment plays a large role. The last few lines on my post-

    It is reasonable to suppose that any differences are due to social and other environmental factors and the genetic component to the differences measured is negligible.

    Regarding measuring intelligence. The problem is that IQ testing has such a ugly and discriminatory history that everyone has a hard time accepting anything to do with IQ. However, some time back, the American Psychological Association
    commissioned an ideologically and racially diverse panel of scientists to review IQ testing. They concluded that IQ measures a stable property of the person (general intelligence) and predicts a variety of life outcomes. Times have changed since immigrants who could not speak English were given IQ tests in English and then pronounced dumb.

    Having said that, let me again stress the point of this post. I personally don't think there are group differences in intelligence between Africans and any other group (as if we can lump Africans in one group). IQ differences for whatever they are worth can be explained by differences in education, opportunity etc, and I agree with Perceval that seperating the genetic component from other factors is difficult. I wanted to point out how we are applying different standards of outrage for different reports of links between race and intelligence. If it is acceptable to study whether certain groups of Jews are smarter than others, then why not apply the same standard to other ethnic groups.