Environmentally in this context just means anything that's not directly genetic or inherited epigenetic. It doesn't mean plants and animals or anything like that.

IQ is mostly genetic (in rich egalitarian countries like the USA), but everyone seems to agree that there's still some environmental factors that smart parents can do to make their children a tiny bit smarter. I don't know exactly what those factors are though. Probably any kind of practice with thinking and studying would help a tiny bit, but perhaps other things to do with better care such as nutrition. But I know there's not a lot that parents can do that helps with IQ long-term, especially when society as a whole is already trying to do everything they can to boost IQ environmentally already.

I can't find anything right now on what effect parents' class (what does that mean? SES?) has on educational attainment for people of the same IQs. Someone else may want to look it up if they're better at googling than me.

But it doesn't matter. We already know that wordsum, IQ, and educational attainment are measuring similar things. Wordsum seems like a good proxy for IQ. It gives sensible answers in all the graphs, and it is said to correlate .71 with adult IQ.

Do you have a point, or some sort of theory about what I was saying? Do you disagree with the idea that Republicans are smarter (except at the top end) than Democrats, or that "liberals" are smarter than "conservatives"?