John Tierney has a fine article in the New York Times on an international study of sex differences in personality. Surprisingly, the researchers found that sex differences were smaller in poorer countries. Their hypothesis is that harsher environments take more of a toll on competitive and aggressive men.
The really interesting finding is that in rich, egalitarian societies, men's and women's personalities diverge more. This seems to me to support the sociobiological notion that sex differences are deep, and are more likely to be expressed the more conditions are optimal for individuals to realize their deep inclinations.
This finding is scary if you think the sexes are the same, and the genders are only different because sexist society makes them so. It is not scary if you think sex differences are complementary, and are a prime example of what is good about diversity.