It should not be especially surprising to find tribalism alive and well in contemporary social structures and behaviors.  Because human beings evolved in small tribal bands, it is as natural for us to act tribally as it is for lions to hunt, or for gazelles to bound away in flight.

To no small extent, it seems to be what we’re genetically programmed to do.

As a result, even today’s most advanced and cosmopolitan cities are teeming with tribal entities.