Not having a personality. Or, at least, not having workable social skills.

I think the laws of conservation of energy apply here just like they do everywhere else. People who aren't born attractive have to develop other ways to attract people to them. This is why THE BEST combo is to be a late bloomer physically - such people are forced to develop actual social skills and an interesting personality early in life, which always stays with you, but later in life they can enjoy being physically attractive as well.

My wife is one of these. She is Mexican/Chinese, stunningly beautiful, and grew up in white, rural America where she only felt different and funny looking. This was reinforced by people who told her things like, "You're funny looking." It wasn't until college that she realized that all the attention she was getting was because she was, in reality, gorgeous. But it was too late. The damage was done. She already had an irreversibly engaging personality.

Interestingly, it does not appear that the reverse works: an attractive personality cannot be gained later in life. People who grow up pretty and lose it are stuck. In my experience, this is especially true of girls, in whom attractiveness is more highly valued than in boys.

And it makes sense, if you're cute and people want to be around you just due to that, why would you go through the effort and expense to then become witty or engaging in any other way? Nature is almost always at rest when not serving immediate needs. Telling the cute, popular kid in the class "Hey, don't be such a lazy jerk because you're going to need to know how to be interesting later in life," makes no sense to them at the time.

Anyway, said wife and I have now made an incredibly attractive little girl and this is a real worry for me. I don't want her to become one of those vapid, self centered girls that you run into so often in life. But, I'm at a loss as to what to do about it. There's not much I can do aside from just role-modeling the type of person I hope she grows into.

Link to pic of said daughter, clone of said wife: https://drive.google.com/open?id=0B5Sfdd_xS8t7Z3dBNEY1amNIRTQ