Just for the record - it's not a class thing; the colonial cultures stem from the Viking culture (largely) which favoured independence over interdependence.

Most other cultures favour interdependence - Asia, rather famously, doesn't have a pension/superannuation program (in general) because their cultures are heavily geared toward elderly living with their children and grandchildren.

What happens to people in those societies who don't have kids?

How is that not pseudo science. Colonialism and Vikings would be separated hundreds of years and long distances. And there are no indication Vikings were less dependent on each other than in other iron age cultures.