I heard that we used to sleep together in large wide beds. Families could stay together, young & old. Why did we stop?
We can still see the evolutionary tendency as children like to snug in a pile, feeling insecure in solitary. Might be an instinct carried over from our animalistic heritage. Could we them assume that our sleep might be better had we brought the tradition over to today? We only think it’s weird as we grew up differently today, but I think not had we been brought up in the past.
These kinds of questions usually don’t do well in this sub because you have loaded a presupposition into the question. You first need to establish whether we did, in fact, have wide family beds. That’s it’s own question. Asking “why” something stopped happening is to suggest it happened to begin with, which is something that needs to be verified in and of itself. On top of that, your conjecture about evolutionary tendencies and further questions about the implications of sleep quality are way off course and speculative.
In short, these kinds of multi-layered questions that are part conjecture and part presupposition tend not to get answers on this sub. Historians don’t typically engage in speculative what-ifs and your question asserts a historical fact that may not be adequately demonstrated as incontestable truth. A better question would be “DID we share the same bed? If so, why did we stop?”