On average, men are bigger, stronger and more aggressive than women. The behavioral and physiological differences are the result of sexual competition: Males tend to fight among themselves for females, and so tend to be bigger and stronger. The pattern holds across most species.
Here's another tendency: If a female is promiscuous, a male is going to have to work harder if he wants to monopolize her than if she is monogamous.
If, say, a man has any intention of starting a family with a promiscuous woman, he will want to monopolize her, since -- in a Darwinian sense at least -- he won't want to waste his resources raising someone else's children.