Tribalism: that's the term often used to characterize the extreme political polarization manifested every day in the United States and many other countries. In fact, to characterize tribalism as merely political would be an understatement. It is something much more comprehensive, reaching much deeper into our lives, as the phrase "culture wars" suggests. We see tribalism on the Left and tribalism on the Right - but not in the middle, because it's the nature of tribalism to create an unbridgeable, uninhabitable chasm between Us and Them. The tribalistic mentality sees things in black and white, good and evil - as a no-holds-barred, zero-sum conflict between Us and Them, for the highest stakes. Tribalism transforms disagreement into mutual hatred, mild condescension into utter contempt.
- From Our Moral Fate: Evolution and the Escape from Tribalism by Allen Buchanan