I believe it's expectations. From the moment your born, your parents have different expectations for you if you are a boy than a girl, or vice-versa. This causes them to dress you different, treat you different, involve you in different activities. At that age a person is just begining to shape there likes/dislikes, thoughts, and building a personality, which will inevitably influence their activities and interests as they age. This makes for very different people.

no big difference men usually is the slave women is the big boss

I think that there is not difference inbetween women and men. Women and men are equal right people. okie?

I think that womans are more sensitive and careful. Today woman have good post in some job because of your competence. The mans have fast reasoning to do something, but don't have the same care. Sometimes very rude because want to show your own way to resolve something else. In some countries the womans can show your point view and have your recognition and others have repression.

Sexual organs.