[pessimizer]

But IQ itself is predicted by parental earnings and parental educational attainment (and, IIRC, mostly by the sheer volume of reading for pleasure during childhood.)

There's a chicken/egg thing here that I think is a cart/horse thing.

[colemannugent]

Education doesn't have as much effect as you might think. It seems that nutrition has a very significant effect on IQ: https://www.sciencedirect.com/science/article/pii/0191886990...

[toasterlovin]

It has roughly 30% predictive power after controlling for the most obvious confounding factors (like the ones you mention).