what about Roman families? https://en.wikipedia.org/wiki/Family_in_ancient_Rome https://en.wikipedia.org/wiki/Family_in_ancient_Rome You had the familia, whic

what about Roman families? https://en.wikipedia.org/wiki/Family_in_ancient_Rome https://en.wikipedia.org/wiki/Family_in_ancient_Rome You had the familia, which was similar to the current nuclear family, but that was wrapped into the larger gens https://en.wikipedia.org/wiki/Gens https://en.wikipedia.org/wiki/Gens people cared not just about the success of their intermediate family, but also their gens, which was similar to a clan. You'll have similar structures in many tribal societies. Do you have actual statistics to support your hypothesis that > My read of history is that it’s the single most stable and ubiquitous human social arrangement by a very long shot. besides just "oh yeah bro, it's my read of history bro, totally rigorous"?