It's complex, to be sure. We have the sort of tribalism that makes us fans of our city's or university's football team; but we still might have a party with fans of the opposing team. One the other hand, some tribal delineations are about "creating separation," and in some cases... the tribes WANT to create tribes to keep themselves apart from others, which also allows for calling others "evil" or "bad" or something else that creates a foundation of fear rather than cooperation.