[rayiner]

Exactly the opposite is true. Adoption studies have been used to isolate the effect of SES itself, and the contribution of that factor is low: https://www.sciencedirect.com/science/article/abs/pii/S01602... (“Proportion of variance in IQ attributable to environmentally mediated effects of parental IQs was estimated at .01… Heritability was estimated to be 0.42.”).

[tptacek]

This is just SIBS data. It has all the standard "Minnesota" limitations: the study is tiny, the cohort isn't demographically representative, adoption isn't itself random, nothing deconfounds the prenatal environment, and the children in the cohort are also adopted at different ages.

It's one thing to call out an interesting paper; it's another to act as if the matter has been settled simply by pointing to SIBS.

[rayiner]

The assertion I was responding to was this: “IQ correlates most strongly with socioeconomic class.”

Find me any study that shows that IQ is more strongly correlated with SES than with parental IQ.