Do genes play a role in cognitive traits like shyness, memory, language skills, and so forth? Of course they do. The only real question is how big a role they play. Take language, for example. In the case of which language you speak, the role of genes is 0%. It's all environmental. But in the case of how well you speak a language, it's much higher.
This is obvious enough that it should be uncontroversial, and it would be except for one thing: if genes have an effect on cognitive traits, it means that genes have an effect on the trait we call intelligence. And if genes affect intelligence, then it's possible that racial differences in intelligence are partly the result of genetic factors.
The fear that this could be true, even though the evidence is currently against it, has driven left-wing opposition to the whole notion of genes and behavior for decades. Luckily for everyone involved, the evidence for the impact of genes is based almost solely on ecological studies, usually of twins. But no matter how suggestive such studies can be, they will never be proof positive of anything. The only thing that has a chance proving anything is biochemical: that is, finding specific gene complexes that affect personality traits. That's basically impossible, which meant everyone could keep merrily arguing forever, safe in the knowledge that no one would ever be conclusively proven wrong.
But lots of things are impossible until suddenly they aren't. Readers with very good memories may recall that a few years ago I wrote about Genome Wide Association Studies (GWAS, pronounced jee-wass). These do the impossible: they allow genetic researchers to find single-nucleotide polymorphisms (SNPs, pronounced snips) that are associated with cognitive traits. At the time, I linked to a paper that claimed to have found SNPs that explained about 5% of the variance in intelligence. But work was ongoing, and the latest studies have gotten up to 20% or so. There's no telling where this number will eventually end up, but it's almost certain that within a few years we'll get to one that's high enough to prove to all but the most recalcitrant that genes do in fact have a considerable effect on human intelligence.
Why mention this? Because in its current issue the New Yorker has a profile of Kathryn Paige Harden, a professor of psychology at the University of Texas at Austin who has written a new book, The Genetic Lottery: Why DNA Matters for Social Equality. Harden has been doing GWAS work of her own and her conclusion is unsurprising: both genes and environment play significant and intertwined roles in most cognitive traits. But there's a depressing coda:
In my conversations with her colleagues, Harden’s overarching idea was almost universally described as both beautiful and hopelessly quixotic....James Tabery, a philosopher at the University of Utah, believes that underscoring genetic difference is just as likely to increase inequality as to reduce it. “It’s truly noble for Paige to make the case for why we might think of biological differences as similar to socially constructed differences, but you’re bumping into a great deal of historical, economic, political, and philosophical momentum—and it’s dangerous, no matter how noble her intentions are, because once the ideas are out there they’re going to get digested the way they’re going to get digested,” he said. “The playing board has been set for some time.”
"Hopelessly quixotic" is a fancy way of saying that no matter what the science says, Harden will never convince people on the left. As Harden puts it, the life of a behavior geneticist resembles “Groundhog Day.” Always the same arguments no matter what.
In fairness, the reason for lefty intolerance of cognitive genetics is obvious and righteous: It's been violently misused for a very long time as a way of proving that certain kinds of people are inferior to others. As Tabery says above, the playing board has been set, and it's almost certain that any new results, no matter how carefully explained, will be used as an excuse by some people to dismiss the possibility of ever improving the lives of the poor, the black, and the oppressed.
But as understandable as this is, it has a big problem: it looks as if we're getting close to a genuine understanding of how genes affect cognitive traits—and the answer is not going be "they don't." At that point the left had better have an argument to make, because they're certain to lose if they just bury their heads in the sand.
The funny thing is that I've never entirely understood lefty opposition to the notion that genes have a significant impact on cognitive abilities. My view has always been close to Harden's: if genes do have an impact, then it makes the case for social safety nets incomparably stronger. It becomes impossible to argue, for example, that poor people are merely lazy if you can point to SNPs that have a clear association with poverty. At that point, it's provably the case that being poor is mostly a matter of bad genetic luck. So what argument is left for leaving anyone in poverty?
Beyond that, as Harden points out, if you know the genetic foundations for a particular trait then it's easier to disentangle its genetic and environmental causes. This makes it easier to accurately identify the environmental causes, which in turn makes it more likely that you can construct social interventions that actually work. In other words, knowledge of genetics is a key part of the liberal project of doing everything we can to improve lives via social programs that are truly effective.
But most people don't see it that way. And beneath it all lurks the deep fear that someone doing GWAS research is eventually going to find SNPs associated with both race and intelligence. I continue to think that's unlikely in anything more than a trivial sense, but I may be wrong. And if I am, what are we going to do?