Well, no, I wasn't trying to claim that the STEM imbalance is because of discrimination. (Or, as you mentioned, because of issues in school, which is not the fault of hiring managers.) I was trying to poke at people who claim discrimination for the STEM situation, but see no problem with the social subjects being very one-sided on the liberal/conservative axis. I was suggesting that, if they are so sure that it's discrimination in the gender case, they should consider the same explanation in the conservative case. (deogeo correctly stated my point.)

Do I think that the gender gap in STEM is because of discrimination? My guess is no, or at least largely no, but I'm not sure I know enough to be dogmatic on that subject.

Do I think that the gap in the social sciences is because of discrimination (or at least bias)? Given the liberal/conservative gap in school administrators, it seems to me that it would be almost a miracle if that wasn't at least part of the reason... but I have no concrete information.