>Absolutely not - and I have direct experience of this.
Everyone who has direct experience of this time has been dead for half a century at least.
>First: multi generational households are extremely common.
Define "extremely common". What percent of people in a given society in a given time period do you think grew up in one?
>Second: people, including children, spend tons of time with other people outside of the parent-child relation. Relatives, often cousins, granparents, and neighbors.
Nobody is debating this. Of course prior to the industrial revolution people moved around less so your friends and neighbors are more likely to be your cousins and if grandma is nearby she'll wind up babysitting more. I don't see this as being meaningful to this discussion since they are outside one's household.
>This is still the case for most agrarian societies outside of the English-speaking world.
Back this up with numbers. Grandma has to live somewhere, but for an child in any given agrarian society to be more likely than not to have have grandma living under the same roof birth rates need to be low to the point of apocalyptic.
>The obsession with the hyper nuclear and exclusionary family is very american.
Is the fact that it's an American obsession supposed to be a bad thing?
Yes, multi generational households were far, far more common from the grandparent's perspective in the past because elderly parents living alone was far, far less common. But from the perspective of the child growing up they still far from the default. The birth rates are simply too high for them to have been default. Nobody here is saying mutligenerational households are bad but the people who think they were default have a skewed understanding of history. Calling something that just has to happen by mathematical necessity "unnatural" (i.e. the comment my initial comment replied to) seems a little over the top.