Congenital adrenal hyperplasia (CAH) is a rare disorder (it occurs in about 1 in 10,000 infants) that can cause girls to develop ambiguous genitalia. Some doctors think CAH also induces "masculine behavior," i.e. a disinterest in having children and an interest in dating other women.

A new study provides a sure-to-be-controversial explanation for why women are less likely than men to pursue careers in science and engineering: exposure to male sex hormones in utero appears linked to a later interest in "things" rather than people.