That's a pretty good example of that, yeah. It's also interesting to note how values, or at least the potential for them, may be conserved across long-term shifts: American culture is notably fixated on geneaology compared to societies where the extended family is a socioeconomic norm; the motivation to have a wider familial context is there, even in families and individuals who are quite comfy with the nuclear pattern. I'm not suggesting it's a causal influence that trumps the economics driving the push for extended families, but I can't help seeing it as influential. The demographic transition and decline of extended families in the US wasn't that long ago...