Not so fast, "obviously".

I believe that "neolocal" households are unique, mostly, to post middle age Western Europe. And the 1950s are anomalous within that time scale.

Otherwise we see patri- or matri local multi generational households in which adulthood is not correlated with setting up a new household at all. You would marry someone and the move into their parents house. Sure you would start having children, but there isn't the same leaving adolescence thing.

Why is that time scale interesting to you as opposed to e.g. the last 150k years?

I don't think we can say anything meaningful about peoples behaviors 10k-150k years ago, and even approaching 10k quickly get's sketchy.

Humans have a long period between when it's possible to get pregnant and when it's safest to get pregnant. This may suggest prehistoric females tended to wait around a decade after puberty, or there was huge selective pressure and we still ended up like this.