Oh no you don't Ken. You're not dragging me into a nature vs. nurture debate that easily. You're one of the smarter posters on here; you know very well I was talking about comparative advantage.

Let's use your recent example. Assume that black people are slightly better than white people at language ability. Assume also that black people are much better than white people at sports. Note that blacks have an absolute advantage in both languages and sport, but they have a relative advantage in sport.

Under these conditions, the situation where all blacks are professional sportsmen, and all whites are language professors, results in maximum benefit for the group as a whole.

The nation would win more Olympic Golds, and more Nobel Prizes in Literature, than under any other combination.

Note also that both groups, by trading, can become better off than they would be under any other combination:
Whites would enjoy the highest possible quality of competitive sports, and Blacks would enjoy the highest possible quality of literature.

And that is what I meant by men being maths professors, and women being language professors.

Phew! That's as much as I'm saying. Not a big fan of controversial topics. This is just simple trade theory if anyone wants to look it up.