I didn't realize that Charles Murray was still talking about his belief that African-Americans are genetically less intelligent than whites. But he is. Over at Vox, Eric Turkheimer, Kathryn Paige Harden, and Richard E. Nisbett report on a two-hour podcast he did recently with Sam Harris:
The consensus, he says, is that IQ exists; that it is extraordinarily important to life outcomes of all sorts; that it is largely heritable; and that we don’t know of any interventions that can improve the part that is not heritable. The consensus also includes the observation that the IQs of black Americans are lower, on average, than that of whites, and — most contentiously — that this and other differences among racial groups is based at least in part in genetics.
I've read The Bell Curve, so I'm not just talking out of my ass about it. And it's a weird book. The vast bulk of it is about the first five bolded items above, which really are part of the scientific consensus. You can argue the details, but it's safe to say that intelligence is real; it's important; it's partly genetically heritable; it's difficult to change; and blacks score lower on IQ tests than whites. The evidence in The Bell Curve on these scores is fine. But then the book gets to a couple of chapters about the genetic basis of the black-white IQ gap, and suddenly the evidence gets very, very fuzzy. In fact, I want to share a brief boxed item included on page 310:
The German Story
One of the intriguing studies arguing against a large genetic component to IQ differences came about thanks to the Allied occupation of Germany following World War II, when about 4,000 illegitimate children of mixed racial origin were born to German women. A German researcher tracked down 264 children of black servicemen and constructed a comparison group of 83 illegitimate offspring of white occupation troops. The results showed no overall difference in average IQ. The actual IQs of the fathers were unknown, and therefore a variety of selection factors cannot be ruled out. The study is inconclusive but certainly consistent with the suggestion the B/W difference is largely environmental.
In one sense, I applaud Murray and his co-author for including this. At the same time, they spend no time engaging with it in the text of the book. But they should: it's only one study, and as they suggest, it has some missing pieces. Still, it's one of the very few studies of African-American and white American children raised in middle-class environments outside of America. The fact that it shows no difference between black and white children is pretty significant—especially since it's highly unlikely that any of these children received any kind of special treatment.
I don't want to pretend that this study is definitive. It's not. But a single disconfirming case is all you need to demonstrate that the black-white IQ gap is entirely non-biological, and this one is pretty close.
It's not impossible that there's a biological difference in intelligence between blacks and whites. That's fundamentally a scientific question, and it hasn't been conclusively proven one way or the other. But the effect of American culture on blacks is so toxic that it's all but impossible to believe that any conclusions drawn in a study of Americans can ever be free of environmental contamination. After all, the Irish used to have low IQs. Jews used to have low IQs. And everyone was quite sure it was due to biology. But when anti-Irish and anti-Semitic animus died out, their IQs increased to normal levels. Amazing, isn't it?
Maybe eventually Murray will find his long-sought gene complexes for cognitive ability, and will be able to show that there really is a genetic difference between blacks and whites. But I doubt it. The evidence just doesn't point in that direction. Maybe in ten or twenty years we'll know for sure.