Further, the evidence cited here does not show that women are just as good at math as men, since the samples used were not randomly chosen. The samples chosen consisted of men and women who had already taken calculus (and some other criteria).
http://www.lscp.net/persons/ramus/fr/GDP1/papers/spencer99.p...
The articles do a good job of showing women are sensitive to stereotype threat. But that's all they show.
Lots of people like to believe they got something from working hard for it, when they really had a lucky breaks (genetics perhaps for math?, height for basketball, rich parents for business).
I see this in sports interviews all the time. The current best in any sport is always "the hardest worker." Too bad nobody else in the league ever thought about that.
What effect nature has on it may be unclear, but it is definitely there.