in which there is more evidence that gender is learned

This is a very interesting article from the New York Times about the "sworn virgins" of Albania.

In this tribal, very patriarchal society, an unmarried woman in a family which has lost all its men can take a vow to be a "sworn virgin" and assume the male role in the family. They live like men. They know they are physically women, as does everybody else, but they live as, and are respected as, full male members of society except that they don't marry.