[embeng4096]

Interesting to see this perspective. I've always associated the focus on nuclear families with a tight-knit neighborhood, almost small-town vibe where everyone knows each other and, yes, are up in each other's business. The breaking of social cohesion I've associated with the more recent phenomenon of it becoming more common to leave one's community to go to school or for a new job.

[ska]

I agree it's a combination of travel an nuclear families but those things are highly interrelated. For what it's worth most of the small-town vibe I'm familiar with from actual small towns is behind the trend to nuclear families; more likely you have multiple generations of multiple families near by who know/grow up with each other. Not uniformly, but very common. Not that I'm highly familiar or anything.

But another important impact I think is that the idea of a nuclear family is pretty much predicated on independence of your little family unit. This not needing anyone else makes it practical to move across the country on short notice, but also makes it possible to break/ignore ties locally. This is of course also affected by the creation of state level supports.

In other scenarios, part of the reason that people got more involved in local community is because they literally risked disaster if they didn't.