Twins reared apart do not exist

Yes-ish. Hence my use of "issue".

The problem is most people's zealous desire to read socially self-serving conclusions into any data they can find on such subjects. And when they really like the Q.E.D. punchline, humans have very low standards for the "logic" used to reach it.

Whoah, no, there is definitely not a consensus for 50-80%, and most of what's being published now refutes the 80% end of that range --- the 80% estimates come from underpowered studies like MISTRA that improperly assumed independent environments for twins reared apart.

As for this snide comment that you posted behind your flagged comment:

"I don't care if you find it fair. If you can't accept that genetics determines the entire organism (stress: entire) and does not stop at the neck, then you'd perceive my later criticisms as much worse than - gasp! oh great heavens! my pearls! - unfair. It is a bitter pill to swallow that some people were simply born with better hardware than yourself, one you are obviously railing against. Now, rush on and down vote this comment as well to lighten the burden of your cognitive dissonance. I'm also finding it difficult to reconcile your use of the flag/report on the parent comment versus the rules dictating and describing what is disallowed content. Disagreement is not against the rules. Perceived "fairness" is not in the rules."

Sorry to inform you that you don't understand the meaning of the verb "determine", as "genetics determines the entire organism" is scientifically wrong for obvious reasons: "influences", yes; "encodes proteins for", yes; but "determines", no.

And, no, I'm not railing against anyone's hardware as I'm pretty satisfied with mine.

This literally doesn't say anything. It's a lot of words, but you've managed to reproduce the exact position the author of the article has. For those wondering what the trick was here: this comment forwards the 40-80% h2 numbers from twin studies, then says "molecular genetics show real, replicable genetic signal for intelligence", rather than showing the 10-30% h2 numbers those studies generate.

It's practically nobody's position that there's no linkage between genetics and intelligence (that would be weird indeed), but it's important for this comment for you to believe that's the counterargument --- otherwise the comment doesn't make sense.

I don't care if you find it fair. If you can't accept that genetics determines the entire organism (stress: entire) and does not stop at the neck, then you'd perceive my later criticisms as much worse than - gasp! oh great heavens! my pearls! - unfair. It is a bitter pill to swallow that some people were simply born with better hardware than yourself, one you are obviously railing against. Now, rush on and down vote this comment as well to lighten the burden of your cognitive dissonance. I'm also finding it difficult to reconcile your use of the flag/report on the parent comment versus the rules dictating and describing what is disallowed content. Disagreement is not against the rules. Perceived "fairness" is not in the rules.

I, and clearly many others based directly on your comment assertion, clearly disagree.

Whether or not you like MISTRA, “they left out the non-identical twins” is a side issue, and the broader evidence that IQ is substantially heritable is extremely strong.

Even if DZA were excluded, MZA alone provides a solid heritability estimate. The DZA sample was small and noisy, and MISTRA uses other twin and family data. Plus, meta-analyses confirm high IQ heritability, typically 0.5-0.8; Later structural-equation models applied to the full MISTRA cognitive dataset (MZA + DZA) estimated the heritability of general intelligence around 0.77, essentially the same ballpark as the original simple estimate. laplab.ucsd.edu. Intelligence is highly heritable, potentially reaching 80% in adulthood, supported by further studies like the Haworth et al. meta-analysis, showing age-related increases in heritability.

Strong evidence for polygenic and SNP heritability is shown from Plomin & von Stumm's 2018 research, showing how polygenic scores predict general intelligence.

Adoption studies further support the genetic influence, as adoptive siblings show weaker correlations compared to biological ones.

Environment is certainly NOT outweighed entirely or beyond merit, but evidence clearly shows the "uncomfortable" result having strong support despite desperate attempts to debunk.

In short; the op's story only works if including the DZA data actually drags the heritability estimate down into trivial territory. It does not.

Later analyses of the MISTRA sample that explicitly include both MZA and DZA twins and use full structural-equation models estimate heritability of general intelligence (g) at about 0.77 in adults. https://laplab.ucsd.edu/articles2/Lee2010.pdf

That is higher, if anything, than the original approximate 0.70. In other words:

The alleged “suppressed control group” does not turn the result into “no heritability”.

The more sophisticated models using that very same DZA data still say “IQ differences in this adult sample are heavily genetic.”

You just don't like this data, and don't want to accept it, because of the implications.