> Results demonstrate that the proportions of IQ variance attributable to genes and environment vary nonlinearly with SES. The models suggest that in impoverished families, 60% of the variance in IQ is accounted for by the shared environment, and the contribution of genes is close to zero; in affluent families, the result is almost exactly the reverse.
[....]
> In the low-SES group, the intraclass correlation was .63 for DZ twins and .68 for MZ twins, consistent with h2 of .10 and c2 of .58; for the high-SES group, the DZ twin correlation was .51 and the MZ twin correlation was .87, consistent
with h2 of .72 and c2 of .15.
[...]
> In the fractious history of scientific investigations of the heritability of intelligence, the effects of poverty, and the relations between them, there has been only one contention with which everyone could agree: Additive models of linear and independent contributions of genes and environment to variation in intelligence cannot do justice to the complexity of the development of intelligence in children. Only recently have statistical models and computational capacity advanced to the point that less simplistic models can actually be fit. Although there is much that remains to be understood, our study and the ones that have preceded it have begun to converge on the hypothesis that the developmental forces at work in poor environments are qualitatively different from those at work in adequate ones. Clarification of the nature of these differences promises to be a fascinating, and hopefully unifying, subject for future investigation.
Something more specific ? Couldn't find anything directly saying what you're claiming here.
I was interested if my info was out of date so I found this https://www.sciencedirect.com/science/article/pii/S019188692... which basically again confirms genetic IQ factor in adults is major. Separated twins correlate, siblings corelate less and virtual twins (same age unrelated siblings) corelate way less.
Anyway I'm no expert on this, but I've heard this view from multiple credible sources and the more I dig in the more it seems supported.
First one that comes to mind is The Blank Slate from Pinker, but I have read that like 15 years ago. But it did shape my view on the subject and I have seen this topic come up many times since.
I don't remember anyone disputing strong genetic component of IQ, other than people uncomfortable with implications. And I am not even that interested in the social implications, but more practical issues like IQ improvement (basically 0 impact from what I have seen other than being physically fit/exercising), implications on parenting (you cant imprint your desired outcomes on your children and need to play to their innate interests and strengths/weaknesses), etc.
I'm sorry, but this is a persistent myth about this space. Lots of research is done every year on the genetic components of behavior and cognition. The field doesn't see it as a yes/no question; there are questions about how far you can get with classic twin studies vs large-scale GWAS, questions about the malleability of intelligence, questions about the validity of IQ tests (see things like test-test reliability), questions about the meaningfulness of psychometric "g", all actively studied.
Again you can just go read Turkheimer's Vox piece for an refutation of your "basically zero impact" thing.
My big thing here though isn't to convince you that you're wrong about your belief that intelligence is innate and fixed. Rather, it's that you opened this thread with a citation to heritability research, and your usage of "heritability" was broken and misleading. With that cleared up, I don't think we need to drag this out.
> This is guaranteed to be a strong factor, there's plenty of evidence on IQ heritability and correlation with income.
> Just because it doesn't predict the outcome fully doesn't mean it's insignificant.
I'm just trying to figure out what your argument was, since it looks like you're trying to convince GP of what they already believed. Income isn't genetic after all.
Consider me convinced if you can source this - I'm not finding anything but opposite - that they strongly correlate the older they get (IQ test).