I think it's pretty funny that no matter how straightforward the methodological critiques of 90s-vintage twin studies are, they always elicit responses as if the critiques were metaphysical, rather than (for instance) deliberately excluding the dizygotic twin control group from MISTRA because it revealed the studies findings were just noise.

The truth is, for these kinds of studies, the whole enterprise might as well be metaphysical; people saying these kinds of things have formed a religious conviction about the heritability of behavioral traits, and their real objection is that science continues to be done on the topic at all. Ironic, given the frequency with which they complain that this science is suppressed.

(I too have a near-religious conviction about this subject, though in a different direction; I do not, however, pretend that conviction is itself a methodological critique!)

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.

I think you may have mistook me for asking for a gish gallop of intelligence arguments, rather than simply pointing out that you ignored the substantance of the article's methodological critique. Which: the comment you wrote upthread is right there for everybody to read.

Which exact passage of my piece triggered this bizarre interpretation? What made you jump from "someone criticizes a 1990 paper in Science for withholding critical control group data" to "this person is subject to magical thinking"?

As it happens, I often run into trouble due to my conceptualist views on the foundations of mathematics (that is, I'm a hardcore physicalist & anti-Platonist cognitivist, which is quite rare among mathematicians), so I find your criticism particularly unfair.

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.

Not a word of this responds to the article itself; it's just a series of subjective judgements you've made about the author and have decided to argue about instead. Always the hallmark of a strong position!

user: jagoff

created: 1 day ago

karma: -3

everything you need to know in a nutshell. username itself even has an implication.