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"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

"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 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%20Online%20CV/(45)%20Turkheimer%20(2000).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...

tptacek 9y ago
More of Turkheimer's writing here, recently, in Vox: https://www.vox.com/the-big-idea/2017/5/18/15655638/charles-murray-race-iq-sam-harris-science-free-speech 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).
- maroonblazer 9y ago
  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-in-voxs-charles-murray-article-bd534a9c4476 https://medium.com/@houstoneuler/the-cherry-picked-science-i...
  - wutbrodo 9y ago
    > 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.
  - pcwalton 9y ago
    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.
    - HoustonEuler 9y ago
      why?
  - tptacek 9y ago
    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.
ktRolster 9y ago
Are IQ tests even accurate enough to measure within a fraction of a point?
- MagnumOpus 9y ago
  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.
  - makomk 9y ago
    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.
    - Houshalter 9y ago
      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.
      - parhurs 9y ago
        >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
        Houshalter 9y ago
        But they control for race, and picked results that generalize across different populations.

tptacek 9y ago

More of Turkheimer's writing here, recently, in Vox: https://www.vox.com/the-big-idea/2017/5/18/15655638/charles-murray-race-iq-sam-harris-science-free-speech 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).

maroonblazer 9y ago
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-in-voxs-charles-murray-article-bd534a9c4476 https://medium.com/@houstoneuler/the-cherry-picked-science-i...
- wutbrodo 9y ago
  > 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.
- pcwalton 9y ago
  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.
  - HoustonEuler 9y ago
    why?
- tptacek 9y ago
  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.

ktRolster 9y ago

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

MagnumOpus 9y ago
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.
- makomk 9y ago
  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.
  - Houshalter 9y ago
    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.
    - parhurs 9y ago
      >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
      - Houshalter 9y ago
        But they control for race, and picked results that generalize across different populations.