“..in a mixed environment, the children themselves seem to self-segregate by socioeconomic status..”
In an article on the social class of the Lucinda Rosenfeld shares the reality of social classes that kids already separate themselves by economic status from a young age. In my experience, it is true though. I became friends with people that came from similar backgrounds with families in similar economic situations. I don’t think I self-consciously knew that I was choosing friends in similar socioeconomic status, but those in the same economic status are usually the most likely for to bond with.