Larry Summers, the beleaguered former president of Harvard, was pilloried for suggesting that scientists examine all possible reasons for sex differences in academia-including genetics. Well, Nicholas Wade's article on sex differences in the NYTimes includes the following paragraph: "Several profound consequences follow from the fact that men have only one copy of the many X-related brain genes and women two. One is that many neurological diseases are more common in men because women are unlikely to suffer mutations in both copies of a gene. Another is that men, as a group, “will have more variable brain phenotypes,” Dr. Arnold writes, because women’s second copy of every gene dampens the effects of mutations that arise in the other. Greater male variance means that although average IQ is identical in men and women, there are fewer average men and more at both extremes. "