Yes, I agree with that as well. People are often set into "tribes," based on their political, economic, religious beliefs...etc. Strangely, often people do not cross their tribes boundaries either. They do not take on any of the ideas of the other tribe even if they make sense or are in their best interest to do so. Religious or political affiliations are the best example. There is no reason that individuals cannot hold multiple beliefs that intersect with other religions or political platforms - yet they rarely do. Instead they argue for the survival of their tribe, as you pointed out.