I guess this doesn't really apply to older people but I am mainly talking under 27 - 28.

I noticed younger woman my age who are attractive all know each other. Its like they can reach each other's mind like " I'm pretty," your pretty so let's be friends.

I also noticed if I go to a random gym woman would also acknowledge other good looking men etc.

I find that guys are similar too but I also find that guys have sort of a competance hierachy. Where guy are more grouped my competance or interest.

I hope this isn't too sexist but maybe its because a lot of woman are programmed to think looks are the main thing in their life?