In my experience americans (at least the limited sample that I know) have a need to find a subculture to identify themselves with, and quick.

I'm not even talking about race here, i'm thinking about the billions of independent christian churches, of soccer fans dressing like soccer players, gang colours etc.

And when they find their subculture, they get stuck in it and become unable to see the others' point of view.

American style racism may be a consequence of that.