> [citation needed] Pretty much the whole of human history? There's no shortage of examples. To the contrary, it's more difficult to find examples that do not

> [citation needed] Pretty much the whole of human history? There's no shortage of examples. To the contrary, it's more difficult to find examples that do not demonstrate tribalism. > difference between individuals as to what they perceive their tribe to be This is a recent luxury that hasn't existed for more than a century. Other than a few cultures here and there that encouraged blended demographics (usually as a consequence of conquest, think Rome).