To explain how selection effects can work alongside the interplay between genes and environment it all revolves around thinking about 1) what traits are well correlated with one another (ie impulsivity, low consciousness, sensation seeking being associated with low iqs while patience, delayed gratification, future orientation with high iqs) and what kind of people would be interested in and do well involving themselves with something (the two being related as people enjoy what they are good at or have a knack for which they then practice and hone from there)

But my thought experiment. Assume you and I were Zimbabweans. You being a wretched nomadic horticulturalist and me a well off and well connected ally of Mugabe's. Obviously my kids would score higher than yours on iq tests, and a lot of this would be environmental. But, would it all be? Could we say that the kind of people who dont move to cities and instead eak out subsistence might be less intelligent to begin with? And those who are interested in and attain political power might be more so to begin with? If we moved forward 100 years, would we still see the descandants of people like me overrepresented in the upper classes and the descandants of people like you overrepresented on the lower classes? I think so. And if we did studies we'd probably find pretty high heritabilities to explain this