My final post "Gender differences"

In our final class we discussed the possibilities of born gender differences vs society causing these differences. We discussed the role testosterone plays in aggressive behavior. We also talked about how testosterone levels may be different in males and females due to gender differences caused by society over years. To me if testosterone causes aggression, and males are currently being born with more testosterone "and have been as far back as we know, although I am open to the possibility this could potentially change in the future, although I don't think it will" Then I don't understand how how one can deny that there are natural born personality differences, and that social situations only add on to these. I do believe that society causes these natural differences to grow, but I believe there are some differences before society plays its role.