Labels
When we put a label to something, we automatically categorize it in relation to ourselves. We see it as an issue of us and them or me and everyone/thing else. It alienates us and we become less tolerant because of it. I think if we stop trying to separate ourselves into categories the world will be much better for it. It's hard because we like labels. It makes things black and white and everything becomes so much easier because of it, but we need to remember the greys too.