Sorry yes, I do not mean to say that I think that men are better than women (on the contrary...)! By 'sexist' I meant to say that I think that it is likely that some of the differences observed between men and women at the present time are not due entirely to 'social training.' I agree that it is difficult, if not impossible to be sure. And additionally, any 'physical' differences are I believe slight, multidimensional, and considerably less signifcant than the social cultural factors.
The site above demonstrates that the belief that women are less scientific runs deep, and exists even among those that do not profess to hold any such belief. As you say, that is probably predominantly due to teaching.
With regard to your final point, by the way, there is a guy I met in the field of language education that argued, comparing schooling with parenting, that people are predetermined to prefer a period of intrinsically motivated, exploration and assimilation before going on to be given pre-determined goals.