We do males and females choose different major subjects in college? This could be because of innate abilities or because of expectations about the prospect within a particular profession. For example, previous to college, girls have typically equal or better mathematics skills than boys, but they are noticeably under-represented in math intensive field in college, like sciences (excluding biology) and engineering. Could this be because female students somehow perceive that their prospects are better in social sciences and humanities?
Basit Zafar claims this is the case, based on a survey of second year students at Northwestern University, a survey that includes questions about expectations. This allows to understand the formation of preferences, not just choices. The short answer is that men care more about money and women look at non-pecuniary aspects. In other words, it looks like biology is still the important factor, and fighting it to force women into science against their will may not be the best thing. However, these results could also be interpreted that women do not want to get into certain fields because money does not buy happiness if (as a woman) you do not feel welcome. Engineering, for example, does not strike me as a field that has the reputation of welcoming women (rightly or wrongly).
On a side note, interesting to see that the Federal Reserve Bank of New York is interested in this kind of work.