Same thing goes for gangs, "good ole' boys network", "in-crowds", brotherhoods, sisterhoods, fraternities, sororities, clans, prides, herds, flocks, pods, schools [of fishes], alliances, teams, commandos, etc.
Some tribes have their own style of clothing, or lack thereof.
Groups will always shoot "poison arrows" towards other groups.
And there are always "armies of ONE".
Tribesman shoots tribesman.
Even from the same tribe, should the paths cross too much.
Read a very interesting article from Newsweek:
"Broad concepts—green, socialist, or market-capitalist ideology—may animate cosmopolitan elites, but they generally do not motivate most people. Instead, the “tribe” is valued far more than any universal ideology. As the great Arab historian Ibn Khaldun observed: “Only Tribes held together by a group feeling can survive in a desert.”"