Comment by tokenadult | Hacker News Reader

Comment by tokenadult | Hacker News Reader

"But all of these genes together account for just a small percentage of the variation in intelligence test scores, the researchers found; each variant raises or lowers I.Q. by only a small fraction of a point.

'It means there’s a long way to go, and there are going to be a lot of other genes that are going to be important,' Dr. Posthuma said."

Indeed. This result is fully predictable from the several previous GWAS studies on IQ that have been done. Any gene that influences IQ in the general population has at most a small effect, and the variance among human individuals in IQ is the result of interaction of hundreds of genes and the environment the individual lives in.

Here's a link to a lot of good writings by one of the leading researchers on human behavior genetics, for more details. I especially like one particular article I'll link just below the link to his collected writings.

http://people.virginia.edu/~ent3c/vita1_turkheimer.htm

Turkheimer, E. (2000). Three laws of behavior genetics and what they mean. Current Directions in Psychological Science, 9, 160-164.

http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...

More of Turkheimer's writing here, recently, in Vox:

https://www.vox.com/the-big-idea/2017/5/18/15655638/charles-...

I assume the authors (all three of them professors of some renown) did not write this headline, because the piece is far better, more careful, and more comprehensive than the title would suggest (I'm no fan of Murray but this is not a typical Vox hot-take).

As a response to the podcast the Vox piece is slipshod. One reads the article wondering if they even bothered to listen to the podcast.

Here's a good takedown of the Vox article: https://medium.com/@houstoneuler/the-cherry-picked-science-i...

> As a response to the podcast the Vox piece is slipshod

Vox is one of my least favorite outlets; not because they're more inaccurate or dishonest than others, but because they intentionally (and somewhat successfully) foster a reputation of facts-first journalism and then use that as a fig leaf for a lot of the same low-quality crap you see everywhere else too.

We can debate as to whether the Vox article is political, but that Medium article certainly is. I feel a bit sick to my stomach after reading the author's Twitter.

why?

This rebuttal is pretty unimpressive:

* It doesn't refute the scientific claims of the authors, but rather takes them to task for disagreeing with points Murray didn't make --- that's fair rhetorically, but fails to address the central thesis of the Vox piece, which is that popular race/IQ ideas are largely junk science.

* It asserts the authority of Charles Murray (for instance, citing him as having written an article rebutting one of Turkheimer's findings), despite Murray not being an expert on the subject --- his scientist coauthor on The Bell Curve is deceased. At one point, in this very takedown, its author even cites Murray observing that he doesn't understand the science.

* It attempts to dismiss the authors by citing James Flynn's critique of black culture, which is ironic on two levels: first, that itself is an argument that Turkheimer and Nisbett didn't make, so the pot is complaining about the kettle, and second because Nisbett himself has gotten into some trouble for making similar critiques of black culture. Memetics isn't genetics.

* It makes seemingly well-grounded arguments about the statistical validity of interventions Turkheimer talked about which, on a second reading, dissipate into handwaving --- what we're left with is a Medium blogger's conjecture against a working scientist's published results.

Turkheimer and Nisbett are at pains to point out that their views aren't uniformly shared by everyone in the field. Rather, they take Murray (and, by implication, Sam Harris) to task for summarizing a contentious scientific debate as if it were settled, but for hysteria in leftist academia. The Vox piece is far more persuasive and credible in this argument than the "takedown" you cite is in its own argument.

I'm not sure why we are spending so much effort on these other GWAS studies when all we need to do is whole-genome sequence HN to figure out where intelligence comes from. I suppose it would be confounded by other behavioral traits that score high here.

1) Re-read Vox piece again, and you will see that aside from the 100% objectively false claim that "no self-respecting statistical geneticist would undertake a study based only on self-identified racial category as a proxy for genetic ancestry measured from DNA", the entire basis of their objection to group differences in IQ are the 5 facts that I spent most of the article responding to.

2) Never said Murray was an authority. I wrote he rebutted Dickens and Flynn on the non-narrowing of the gap in the last 25 years, which is correct, regardless of whether he's an "authority." Also, I didn't say he "doesn't understand the science," I said he doesn't understand the details of the mathematical techniques in a paper regarding the nature of the Flynn effect. This seems unimportant because Wicherts's conclusion -- that the Flynn effect gains have a different structure than the B-W IQ gap -- is uncontroversial.

3) Not really. I was citing Flynn for making the same point as Wicherts's above re: structure of FE gains, a demonstration that it's not just Wicherts's theory. I quoted him saying un-PC things about black culture just to demonstrate that in order to rebut Murray's unPC claims many scientists come up with different unPC hypotheses.

4) Talk about "handwaving": it would be helpful for you to elaborate what arguments you think actually "dissipate" on a second reading but I doubt you will.

And I would care more about your ad-hominem attack were it not for the Rindermann survey. Which brings me to my final point: you have it completely backwards when you say "Turkheimer and Nisbett are at pains to point out that their views aren't uniformly shared by everyone in the field. Rather, they take Murray (and, by implication, Sam Harris) to task for summarizing a contentious scientific debate as if it were settled." The scientists at Vox rather explicitly say that no credible scientists attribute some group IQ differences to genetics, while the survey I cite in the Medium article is convincing that is an inaccurate assessment of the views of researchers in this field. Moreover it's pretty clear that Harris does not believe the science is settled, and Murray also thinks that we should wait for direct DNA evidence to say that it's settled.

Are IQ tests even accurate enough to measure within a fraction of a point?

They don't need to be, at sample sizes in the 100,000s. Most of these studies are not even using IQ tests but "years of education" which is a measure of IQ with a laughably large standard error - but with very large sample sizes very precise estimates can be made of the effect of a particular SNA on the affected people's intelligence.

Using "years of education" as a measure seems like it might just end up measuring how well you can use genes to identify whether someone's of the right socioeconomic class to get their children into university. I can't really see any way around this.

Well I believe they control for social status. And also a lot of other things, see gwern's comment above. In any case, I don't expect there to be genes that predict social class. And if there were, that would be super interesting in itself.

>I don't expect there to be genes that predict social class

Genes for skin pigment

>super interesting

If you've never heard of inequality before, I guess

But they control for race, and picked results that generalize across different populations.

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