In the less affluent areas, I'd expect children not attending daycare to just not be getting anything at home. Presumably their parents are both working and cannot afford daycare. In the more affluent areas, I'd expect children only don't attend daycare if their parents prioritize their children over their jobs, and so they'd be getting much more positive attention than in a daycare. But, of course, we'd have to see a study differentiated by socioeconomic status to see what is actually the case.