update: invoking cultural evolution as an explanation is most of the time tenuous, see https://www.gwern.net/Backstop#artificial-persons: “cultures or groups are rarely driven extinct, with most large-scale ones persisting for millennia; such ‘natural selection’ on the group-level is only tenuously linked to the many thousands of distinct practices & beliefs that make up these cultures; and these cultures mutate rapidly as fads and visions and stories and neighboring cultures and new technologies all change over time"