The historical pressure to have more than one child goes way back. Think of it this way. It used to be that a family was a workforce. We were an agrarian people, and you needed children to farm your land. So if you were going to survive or even thrive, the best chance of doing that was with the most kids possible to help you do that. Obviously that changed. The Industrialization Revolution came around. We totally redefined what a family does. Children began to cost more than they would provide. And we maintained the notion that it is still better to have more children. I think that part of that is because we decided back in those days too that an only child was lonely and, yes, if you grow up in a farm in a rural area in the 18th century, it is probably pretty lonely. But that´s not how most of us live anymore, and yet we continue to think that, especially in America, a big family is the way to go.