Comment by tptacek
6 days ago
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.
okay, I saw the paper saying 500 genes are involved. So does a single number for iq mean anything? Does the number depend upon what is tested?
We have essentially no mechanistic understanding of gene/intelligence interactions. Rather, we have cohorts of people tagged with traits (educational achievement, tested IQ, height, etc), all sequenced, and then we can run correlation surveys across all their genomes to identify correlations between alleles and traits. When you do that, you get 10-30% heritability numbers; the gap between that and the range for MZ/DZ twin studies (the 50-80% you often see) is "the missing heritability problem".
Regarding missing heritability: https://www.astralcodexten.com/p/the-good-news-is-that-one-s...
"That is, once you include the rare variants, the amount of genetic variation that “should” exist but doesn’t shrinks to only 12%. Plausibly an even bigger study, investigating even rarer variants, could shrink the gap further, all the way to zero."
Of course, even then heritability will not be 100%.
does epigenetics play a significant role? Within one lifetime or several generations?
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