The key to genetic similarities among people, says Risch, is not religion but endogamy—the practice of marrying within a specific group, which leads to its genetic differentiation.
These mutations largely occur in parts of the DNA with no specific function, but they can lead to diseases such as Tay-Sachs or dysautonomia.
One of the first to publish reflections on the subject was French physician François Bernier in 1684.
A century later, others—such as Carolus Linnaeus, inventor of zoological taxonomy—followed suit.
The argument makes some uneasy, a fact acknowledged by one of the study’s authors, Henry Harpending, who said at the time, “Absolutely anything in human biology that is interesting is going to be controversial,” given the possibility of using such information for promoting the superiority or inferiority of certain groups.
The implication that Jews have a higher IQ than other groups is bolstered by the disproportionate number of Ashkenazi Jews who are Nobel Prize winners and world chess champions, say Harpending and the rest of the Utah team.