It also explains why The Left hate the nuclear family. It reminds me of the HBD finding where success retention by SES (proxy for class) remains constant in family lines through the centuries. The losers stay losers, the winners remain winners.
We’ve found the piggy in the middle missing variable.
Note: this disproves hypergamy, actually an argument about social mobility, so don’t expect the manosphere to cover it. Like covering the hatefact that married men are happier and live longer, they haven’t the balls.