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?The "faulty" genes, Cochran concluded, make Jews smarter.
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."
That provocative — some would say inflammatory — hypothesis has landed Cochran and Harpending in the middle of a charged debate about the link between IQ and DNA.
They have been sneered at by colleagues and excoriated on Internet forums. They have been welcomed to speak at a synagogue and a Jewish medical society. They were asked to write a book; that effort, "The 10,000 Year Explosion," was published early this year.
Scientists are increasingly finding that propensities for human behaviors — for addiction, aggression, risk-taking and more — are written in our genes. But the idea that some groups of people are inherently smarter is troubling to many. Some scientists say it has such racist implications it's unworthy of consideration.
"What are their theories about those on the opposite end of the spectrum?" asked Neil Risch, director of the Institute for Human Genetics at UC San Francisco, who finds the matter so offensive he can barely discuss it without raising his voice. "Do they have genetic theories about why Latinos and African Americans perform worse academically?"
The biological basis for intelligence can be a thankless arena of inquiry. The authors of "The Bell Curve" were vilified 15 years ago for suggesting genes played a role in IQ differences among racial groups.
And here's Karen Kaplan's LA Times' article on John Hawks back in February.