Henrich, J. “The Weirdest People in the World” (London: Random House, 2020)

One specific culture has come to completely dominate the world, to whom Henrich ascribes the publisher-friendly acronym WEIRD (Western, Educated, Industrialised, Rich and Democratic.) He believes that the key event in the origin of this culture was the breaking of kinship structures by the Catholic Church through changes to the ritual of marriage; in particular, the banning of cousin marriage (even sixth and seventh cousin marriage was banned by the millennial Church).

… but it was his description of the Matsigenka that put me on the next step:

Households within the tribe are economically independent. Members live in widely dispersed hamlets with their extended families, and clear new land by assarting. Physical dispersal into the landscape itself was a cultural adaptation, that reduced the impact of predation by slavers (from the pre-Columbian, to C15th Inca, to C16th Spanish, to C20th timber and rubber exploitation.) Above the household, there are no decision making or organisational institutions. Social life is highly egalitarian, and kin-based. The Matsigenka believe that individual action matters, and can influence their fate. Henrich found the Matsigenka were even more individualistic and independent than WEIRD people; at large social gatherings, many Matsigenka remain noticeably uneasy and most preferred a solitary life among intimate family members.