Posted on May 6, 2010

Some Scientists’ Openness to the Possibility of Genetic Differences in Mental Traits Among Racial and Ethnic Groups

Eugene Volokh, The Volokh Conspiracy, May 4, 2010

As I said in my first post on the Harvard e-mail controversy, I believe we should be open to the possibility of genetic racial differences in intelligence, just as we should be open to a wide range of other scientific possibilities. I have not simply been arguing that people should have a First Amendment argument to express such openness. I have been arguing that such openness is in fact sound, and that closing off this possibility in our minds (and in our conversations) cannot be sound, especially given how much scientists have yet to learn about the genetic basis of intelligence.


But in case it’s helpful, I thought I’d pass along some recent statements from scientists who work in this field–statements that I think help highlight the correctness of the view I defend, and its practical importance for the coming years. First, a 2006 item from noted Harvard psychologist Prof. Steven Pinker, who is actually skeptical about claims of racial differences in intelligence:

The year 2005 saw several public appearances of what will I predict will become the dangerous idea of the next decade: that groups of people may differ genetically in their average talents and temperaments.

  • In January, Harvard president Larry Summers caused a firestorm when he cited research showing that women and men have non-identical statistical distributions of cognitive abilities and life priorities.
  • In March, developmental biologist Armand Leroi published an op-ed in the New York Times rebutting the conventional wisdom that race does not exist. (The conventional wisdom is coming to be known as Lewontin’s Fallacy: that because most genes may be found in all human groups, the groups don’t differ at all. But patterns of correlation among genes do differ between groups, and different clusters of correlated genes correspond well to the major races labeled by common sense.)
  • In June, the Times reported a forthcoming study by physicist Greg Cochran, anthropologist Jason Hardy, and population geneticist Henry Harpending proposing that Ashkenazi Jews have been biologically selected for high intelligence, and that their well-documented genetic diseases are a by-product of this evolutionary history.
  • In September, political scientist Charles Murray published an article in Commentary reiterating his argument from The Bell Curve that average racial differences in intelligence are intractable and partly genetic.

Whether or not these hypotheses hold up (the evidence for gender differences is reasonably good, for ethnic and racial differences much less so), they are widely perceived to be dangerous. Summers was subjected to months of vilification, and proponents of ethnic and racial differences in the past have been targets of censorship, violence, and comparisons to Nazis. Large swaths of the intellectual landscape have been reengineered to try to rule these hypotheses out a priori (race does not exist, intelligence does not exist, the mind is a blank slate inscribed by parents). . . .

Advances in genetics and genomics will soon provide the ability to test hypotheses about group differences rigorously. l;. . . [T]he prospect of genetic tests of group differences in psychological traits is both more likely and more incendiary [than the more commonly discussed prospects of cloning and human genetic enhancement], and is one that the current intellectual community is ill-equipped to deal with. {snip}


Or consider this material from 2009 Nature article by Profs. Bruce T. Lahn (Univ. of Chicago) and Lanny Ebenstein (UC Santa Barbara), titled Let’s Celebrate Human Genetic Diversity:

[E]nough evidence has come to the fore to warrant the question: what if scientific data ultimately demonstrate that genetically based biological variation exists at non-trivial levels not only among individuals but also among groups? In our view, the scientific community and society at large are ill-prepared for such a possibility. We need a moral response to this question that is robust irrespective of what research uncovers about human diversity. . . .

The current moral position is a sort of ‘biological egalitarianism[,]’ . . . the view that no or almost no meaningful genetically based biological differences exist among human groups, with the exception of a few superficial traits such as skin colour. . . . We believe that this position, although well intentioned, is illogical and even dangerous, as it implies that if significant group diversity were established, discrimination might thereby be justified. . . .{snip}


Other scientists say related things. University of Virginia psychology professor Jonathan Heidt asserts that “Recent ‘sweeps’ of the genome across human populations show that hundreds of genes have been changing during the last 5-10 millennia in response to local selection pressures,” and that “traits that led to Darwinian success in one of the many new niches and occupations of Holocene life–traits such as collectivism, clannishness, aggressiveness, docility, or the ability to delay gratification” may therefore prove to be ethnically linked (to a degree, of course) on a genetic level. (By the way, as I said in my first post on this matter, I would no more rule out the possibility that Jews, my own ethnic group, are genetically predisposed to more acquisitiveness than average than that some ethnic groups are genetically predisposed to less intelligence than average–though of course I would not accept either conclusion as true without solid evidence. You can’t rule out scientific possibilities just because some evil people had, for unscientific reasons, asserted similar things in the past.)

“I believe that the ‘Bell Curve’ wars of the 1990s, over race differences in intelligence,” Heidt continues, “will seem genteel and short-lived compared to the coming arguments over ethnic differences in [these sorts of] traits. . . . [W]hatever consensus we ultimately reach, the ways in which we now think about genes, groups, evolution and ethnicity will be radically changed by the unstoppable progress of the human genome project.”

Likewise, here’s an excerpt from an article by University of New Mexico psychology professor Geoffrey Miller in The Economist, Nov. 13, 2009:

[Coming developments in] genetics will reveal much less than hoped about how to cure disease, and much more than feared about human evolution and inequality, including genetic differences between classes, ethnicities and races. . . .

In 2010, . . . [d]ozens of papers will report specific genes associated with almost every imaginable trait–intelligence, personality, religiosity, sexuality, longevity, economic risk-taking, consumer preferences, leisure interests and political attitudes. The data are already collected, with DNA samples from large populations already measured for these traits. . . .

When sequencing costs drop within a few years below $1,000 per genome, researchers in Europe, China and India will start huge projects with vast sample sizes, sophisticated bioinformatics, diverse trait measures and detailed family structures. (American bioscience will prove too politically squeamish to fund such studies.). . . .

We will . . . identify the many genes that create physical and mental differences across populations, and we will be able to estimate when those genes arose. Some of those differences probably occurred very recently, within recorded history. Gregory Cochran and Henry Harpending argued in “The 10,000 Year Explosion” that some human groups experienced a vastly accelerated rate of evolutionary change within the past few thousand years, benefiting from the new genetic diversity created within far larger populations, and in response to the new survival, social and reproductive challenges of agriculture, cities, divisions of labour and social classes. Others did not experience these changes until the past few hundred years when they were subject to contact, colonisation and, all too often, extermination.

If the shift . . . to sequencing studies finds evidence of such politically awkward and morally perplexing facts, we can expect the usual range of ideological reactions, including nationalistic retro-racism from conservatives and outraged denial from blank-slate liberals. The few who really understand the genetics will gain a more enlightened, live-and-let-live recognition of the biodiversity within our extraordinary species–including a clearer view of likely comparative advantages between the world’s different economies.


Of course, these scientists may be wrong. There are doubtless other scientists who disagree with them. The history of science is filled with highly credentialed and respected scientists who have proven to be wrong.

But the question right now isn’t whether there are the genetic differences among groups that these scientists suggest might (or might not) exist. It’s whether we, both scientists and interested laypeople, should be open to the possibility that they exist, and whether those of us who admit–in an e-mail to a close friend–that such openness should be publicly pilloried for daring to think that this is indeed a possibility. The answer, it seems to me, is that we should indeed be open to this scientific possibility, as the scientists whom I quote above are open to it, and that we should not be condemned for this openness.