The "us vs them" at!@#$%^&*ude exists at every level of human society. In our homes, at school, at work, in our cities, states, and countries. When we refer to it in a negative way, we call it things like: racism, sexism, anti-semitism, bigotry, cliques, gangs, sexual harr!@#$%^&*ment, bullying, etc. When we refer to it in a positive way, we refer to it as: family, friends, nationalism, patriotism, capitolism, etc. It's all just a big euphemism for "us vs them".