Hey, saw a great comment some months back by someone who was a scientist/doctor/some kind of biologist maybe who talked about how one the basic intuitions around men and women being different was that Nature does not make identical copies across species, i.e it would be retarded to make man and woman the same because by differintiating them just a little bit (for example, risk taking behavior) you can stabilize the species and ensure better fitness. I have googled for the term and tried searching around litterature around this, but alas.