[RT Wolf]

One theory (and the one I believe to be correct) comes from evolutionary biology and simple group dynamics. Most human beings' (even those living in "advanced" societies) behaviour is surprisingly similar to ape or early human or tribal behavior.

Women are attracted to status and men are attracted to fertility and youth. There's a couple of ways to measure status in today's society such as money, power. Higher status men also carry themselves confidently and are more confident because of their social position. Forunately, the attraction mechanism is not that smart, and women (subconsiously) think that if someone is confident, they're higher status. Ergo, women are attracted to confident males (who might or might not in fact be high status). Jerks who are also fairly confident-appearing, attract women for that reason. Higher status males can have their pick of the women in a given group, so women are more accepting of their situation including being taken advantage of and being just plain neglected.

Why women want higher status males is fairly simple, there is (and/or was) greater protection and perks for being a high status female, including protection of your child, better genes for that child and the greater likelihood of your own genes being passed on (because a kid with better genes is more likely to survive and breed), and more food and so forth that the male received for simply being higher status. So our genes built a heirarchy into us cause it served our genes well.

I hope I've explained myself clearly, my head's a little murky right now.