People in coastal communities are generally going to be wealthier. IMO, it’s a combination of having enough money to afford spa treatments, plastic surgery, personal trainers, good clothing (and those folks who help rich people find the right clothes…the word escapes me at the moment). A lot of the women I know around here (coastal North County) spend an inordinate amount of time and money on their appearance. I was one of only a few moms in my kid’s kindergarten class who didn’t have some kind of work done. Most of them went to the gym on a regular basis. Most had their hair and nails professionally done, too. You have to have quite a bit of time and money to be able to do all of this, and “average” people tend to have little of either time or money.
It’s also probably because money attracts beauty. The wealthiest people, especially men, can attract the most beautiful women. They will tend to have more beautiful children, too. And since looks, for both men and women, have an effect on how much money one makes, that’s probably a factor for both sexes, as well.
As for Silicon Valley, while there is a lot of money up there, I think that the hippie/feminist culture, along with the nerd culture (since so much of that money is in tech), might lend itself to the slightly less beautiful appearances of the people up there. Just a guess.
