Kin selection. Family, Kin, Kith, Tribe, Nation, Race. Humans remain tribal. We reside in tribal groups. We mate in tribal groups. We create friendships in tribal groups (often within very narrow genetic distances). We work in tribal groups. We organize reproductively, socially, economically, politically, and religio-militarily in tribal – meaning kinship – groups.
There is political value in the attempted utopian-socialist era we still live in, to create a mythos of universalism. But this survives is only because man is a rationally self interested creatures, and the lower classes will choose the female reproductive strategy (universalism) under alpha-threats, and choose male reproductive strategy (tribalism) under threats from competing underclass threats.
This explains all of world political tensions at the moment.