I was sent this story about genes and IQ, and right from the beginning, my alarm bells were ringing. This is crank pseudoscience.
Gregory Cochran has always been drawn to puzzles. This one had been gnawing at him for several years: Why are European Jews prone to so many deadly genetic diseases?
Tay-Sachs disease. Canavan disease. More than a dozen more.
It offended Cochran’s sense of logic. Natural selection, the self-taught genetics buff knew, should flush dangerous DNA from the gene pool. Perhaps the mutations causing these diseases had some other, beneficial purpose. But what?
At 3:17 one morning, after a long night searching a database of scientific journals from his disheveled home office in Albuquerque, Cochran fired off an e-mail to his collaborator Henry Harpending, a distinguished professor of anthropology at the University of Utah in Salt Lake City and a member of the National Academy of Sciences.
“I’ve figured it out, I think,” Cochran typed. “Pardon my crazed excitement.”
The “faulty” genes, Cochran concluded, make Jews smarter.
Why are European Jews prone to certain genetic diseases? My first answer would be to consider that they are a sub-group isolated by a history of bigotry from the outside, and strong cultural mores from the inside that promote inbreeding. These are variations amplified by chance and history.
I would not be offended by this. It’s logic, too. Natural selection is important, but it’s not everything — but so often, “self-taught genetics buffs” get the emphasis all wrong, and think of evolution as a machine that churns out generations that are relentlessly optimized for the best of all possible solutions, and these are the people who are also unsatisfied that evolution also churns out mistakes that are perpetuated over and over again. Errors happen, and their existence does not need an explanation; there is also no tendency by a benign nature to balance every individual’s shortcomings with a beneficial mutation.
Mr Cochran’s flaw is in his premise. There is no reason to assume that the frequency of every allele in a population must be the product of a selective advantage. The mathematics was worked out in the last century, and we know that even deleterious alleles can go to fixation in a population. His frenzied scribblings and off-the-wall database searches were driven by a need to reconcile the facts with his naïve and erroneous vision of evolution, and are not very convincing.
Here’s another explanation: this isolated subgroup of Ashkenazi Jews also had a culture with a deep historical respect for scholarship, and emphasized and supported education and learning to a greater degree than the larger culture surrounding them. Their children therefore begin life with a leg-up on intellectual pursuits. We don’t need a genetic explanation for their better performance (on average) on academic tests. Note also that this does not exclude a genetic component, but now at least we’re talking about an environmental factor that favors selection for intelligence. Again, though, I haven’t seen any convincing evidence for such a thing; personally, I think our intelligence is built on a shared genetic/development core that enables a wide range of kinds and degrees of intelligence to be expressed in response to environmental conditions.
But here’s the final confirming evidence that Cochran is a crank and a non-scientist.
It would be easy to test the theory, said Steven Pinker, a Harvard cognition researcher: “See if carriers of the Ashkenazi-typical genetic mutations score higher on IQ tests than their noncarrier siblings.”
Cochran and Harpending readily acknowledge the need for such experiments. But they have no plans to do them. They say their role as theorists is to generate hypotheses that others can test.
“One criticism about our paper is ‘It can’t mean anything because they didn’t do any new experiments,’ ” Cochran said. “OK, then I guess Einstein’s papers didn’t mean anything either.”
I don’t agree with Pinker that it would be easy — there’s going to be a lot of individual variation in performance, and I think it’s very hard to split the variables of culture and genetics apart in these kinds of tests. But at least he’s offering a positive approach to the problem, and that would be a good starting point.
But Cochran isn’t interested in doing them? He’s just a theorist? That’s where he begins to sound exactly like an intelligent design creationist.