https://waitbutwhy.com/2019/08/giants.html has a pretty convincing (to me) explanation of this. Basically the way human psychology works is that people have conflicts at the highest available struggle, and when no outside enemies are a threat they turn internally. For a nice graphical illustration, skip to ”Me against my brothers; my brothers and me against my cousins; my cousins, my brothers, and me against strangers.”
https://waitbutwhy.com/2019/08/giants.html has a pretty convincing (to me) explanation of this. Basically the way human psychology works is that people have conflicts at the highest available struggle, and when no outside enemies are a threat they turn internally. For a nice graphical illustration, skip to ”Me against my brothers; my brothers and me against my cousins; my cousins, my brothers, and me against strangers.”