If you are correct, then brain physiology doesn't explain the difference. So then, what does?

I ask the question because I have a suspicion that whatever causes women to think less like economists than men also makes them less likely to join communities like Less Wrong. I, myself, do not have a good answer to this question. Furthermore, I suspect that until we do have a good answer to this question, our strategies for increasing the proportion of females on Less Wrong will be ineffective.