MofT, you make some good points. It's complicated.

Differences in ability do exist, and I've seen how they play a role in how people interact with their children. As an example, I know people who aren't very bright, and from what I've seen, they have no or nearly no books in their house. Their kids are young, and are starting to get overweight and pasty-looking, due primarily to the amount of junk food they consume. They're a low SES family.

Yet one parent is very active in the PTA and is all over the kids to get their homework done. Both parents clearly love their kids, invest a lot of time into them in many ways, and want the best for them.

It could be argued that no one ever taught the parents about the value of activities like reading or healthy eating, and therefore they don't know their value or that there is some kind of low-SES issue there. But in this case, that idea seems odd, given the high level of involvement in school, family-wide sports involvement, and the lengths these people go to to find affordable enrichment programs. I suspect, but don't know, that the lack of books is due to a lack of interest. The junk food issue is more complicated than simple SES.

It's possible that the kids will fare better than their parents and that their children will do better still. I don't know; there are a lot of factors at work. I do know that these people work very hard with their kids, and that in many ways, they're setting them up to do well with their lives.