The Larry Summers controversy (see here and here) is probably going to make it even harder to do no-holds-barred research on the fascinating subject of gender identity. But fortunately, academia is probably still too competitive for obscurantism to triumph. Evolutionary biology has stood fast against religious fundamentalism for over a century; I don't think evolutionary psychology will be closing up shop just because Summers caught a little grief.
And if you want a little concrete proof that some scholars will not be scared off, this Wednesday the Public Choice Center at GMU will be hosting Prof. Steven Rhoads of the University of Virginia to talk about his new book on gender differences.
Rhoads documents that men and women have, on average, markedly different attitudes about work, sex, family, and what's interesting. Like what? Unless you're a Martian, you already know. But if you are a Martian, or just want a little more precision, the best online test of gender identity should give you a pretty good idea.
Personally, I would love to see gender identity get the attention it deserves from personality psychology. (I would also love to see personality psychology get the attention it deserves from economics). It is well-documented on the Five Factor Test that women are noticeably higher in Agreeableness and Neuroticism than men are. But after you answer all the questions, perhaps you will come to the same conclusion I did. The test is excellent in many ways, but the main reason it does not recover a Masculinity/Femininity factor is that it doesn't contain the questions you would need to detect it. Questions like:
"I like to wear pink."
"I enjoy spending time with my extended family."
"I like watching sports."
"I am attracted to members of the opposite sex who are 10 or more years older than me."
If you added questions of this sort, I bet you would not only find overwhelming statistical evidence of a Sixth Factor. You would also probably find that Masculinity/Femininity, unlike all of the other factors, is bimodal, with most men at one end of the scale and most women at the other, and a fairly small number of androgynous men and women in the middle.