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?