I'm talking about humans by the way but other animals may also be included. Apart from the obvious reproductive organ differences and physical differences, is there a difference in the mindset? Now I see girls and boys developing different interests since they are born. Girls start playing with dolls and boys with toy-cars etc. Coming to the realms of science and engineering, some departments are filled with males and some have more females. Just to give an example - I find very few females in the mechanical engineering department. You can see this outside science and engineering too. So does there exist a difference in the brain which causes different interests and mindset or is it a cultural thing?