[A] scientific study just published in American Psychologist provides strong reasons to doubt that there are many inborn differences between genders. Janet Shibley Hyde, of the University of Wisconsin-Madison, has shown that in most cases psychological differences are small or nonexistent. It turns out that there is no difference in how good girls and boys are at maths. Girls' self-esteem is widely believed to nosedive on entering puberty; in fact, that of boys does so as well. In most respects, the genders communicate in the same way - forget all that stuff about men interrupting more and being less self-revealing. Only a handful of the nostrums of evolutionary psychology survive Shibley Hyde's scrutiny. It's true that women can't throw things as hard or as far; they do not masturbate nearly as much, and are not up for casual shagging to the same degree; and they physically attack others dramatically less often. Taken overall the study shows that, to a very large degree, in terms of gender difference, we do start as blank slates, and it provides one of the strongest ever scientific foundations for equal-sex social policies. But then how could we ever have doubted it?
How could we ever have doubted it? Well, it is just one study sooo . . . Here are details on the study.
NOTE: Yeah I know Summers didn't say men were smarter than women, he just said they had greater aptitude in math and the sciences than women. Huge difference.