Beyond that, if there are genetic effects we would expect to see them more strongly in race comparisons than economic status comparisons.
I would expect the opposite to be true, based on results that genetic effects are most important at high economic status.
We may need to be more explicit about the claim under discussion. I intended to say that if you partitioned students by race and economic status, ran a regression, then also added in some gene markers and ran another regression, you would find the race coefficient decreased more than the economic status coefficient.
The data you are providing suggests that genes become a better way to differentiate students at higher economic status from each other, which does not appear to disagree with my claim.
I will also note that the mechanism behind your data- increased uniformity of parenting styles- might also be strongly noticeable when looking at race instead of economic status.
I want to learn what's well-understood about education. I expect to launch myself into some endeavors in teaching the first few levels of epistemic and instrumental rationality - ie., critical thinking and problem solving. I'm a little suspicious, though, of the scattered educational texts that I've so far read. In particular, education seems like a field where it's easy to have motivated thoughts, and hard to gather good data.
With my background (Math and CS) I'm a little at sea in educational literature. Does anyone know of good, reductionist-grade or evidential-grade, introductory texts in education?