[riggernetard]

> Or is cultural and social inheritance as influential as genetic inheritance

No, it isn't. For intelligence, in adulthood, it clearly isn't. For harder to measure skills, current estimates are at around half and half, but the error is mostly in the environment category. So much general-population variance is genetic (and that's only amplified at the highest skill levels - you need great 'cultural and social influence', but also great genes, lol)

> Did they try to marry their own? Naturally - out of snobbery and opportunism if for no other reason.

fun fact, the trait that shows the most assortative mating is intelligence. curious!

> I used to live in an upper middle class area, and a worrying number of the people were very polished thieves.

and I know a worrying number of lower class thieves. '20% of rich people are grifters' doesn't impune rich people as a whole, any more than Tony the crack money launderer impunes poors.