(Bostonian, do you see why it's rude?)
So why do more girls care more about being glamorous and beautiful? My answer is the sociobiological one.
So I'm going to infer that your answer to my question was "no."
Here's the thing. Most people aren't immune to culturally stereotyped messages telling them how they should behave. So when authority figures say things like, "Boys are better at math" and "Girls are supposed to look pretty," people internalize those messages and accept them without question or without thinking about why they believe them.
I will ask you to consider that perhaps
you have internalized some of those messages.
Human society has been extremely biased in its gender expectations throughout our history and in a nearly universal way. As a result, it's not possible to "prove" that boys are better at [insert subject or job] and that girls are better at [insert subject or job], because any data is too tainted, and in a variety of ways.
As an example of tainted thinking, people used to believe that women couldn't be doctors, and they were even barred from entering the field in many places. If you had asked men 100+ years ago, they would have answered that women simply weren't capable. Yet no one would say that today, and medical school classes in the US are half men and half women. Somehow, I don't think that women's brains have evolved to handle being a physician in the last hundred years or so. But women have begun to stand up for their rights in that time.
IMO, the problem is at least partially rooted in competition. When one group wants to keep as much of some resource (including jobs) to itself as possible, its members will act in a way to meet that goal. Discriminating against people and the use of gender roles is one way to do that.
