[color=66ff00]Women generally have the mentality that what they cannot have is attractive, mostly because they see it as a challenge and as they say nothing worth fighting for is worth having.
As for the jerk complex; it's related to the above fact, guys who mistreat girls can give the appearance of being a challenge, something she has to fight to 'control'. They're seen as more spontaenious and therefore potentially more interesting to be around.
Unfortunately hollywood and television has given us this picture of the perfect guy as a touchy feely type and the perfect girl as a go getter.
In actual fact if you consider the real motivations of men and women you'll note that we are still pretty much locked into the same old patterns; guys want a feminine girl and girls a masculine guy. Obviously there are exceptions but the rule is a pretty good guide-line.
In my experience girls under the age of about 22 to 23 don't really know what they want, they go for attractive guys as this gives them a better status amoungst their peers, women in their mid 20's tend to realise that happiness and looks are independant and hence they go for guys that please them emotionally rather than just going for looks or status.
[/color]