Turkheimer speaks!

Time to respond to Eric Turkheimer’s  post.

In my review of Carl Zimmer’s book, I said that the existing fixation index values between continental races are compatible with very significant physical and behavioral differences between those races, because wolves and coyotes have exactly the same value of Fst as Yorubas and Mormons. Lewontin said that two groups with that Fst couldn’t be very different, yet coyotes and wolves are very different – so Lewontin was wrong.  Turkheimer seems to agree with me on this, although he probably doesn’t think Lewontin is full of shit. He should.

Turkheimer says that human behavioral differences are highly polygenic: true enough. And he says that makes them very significantly different from single gene effects – ” big mechanistic single gene effects and complex polygenicity” .  He talks about how complex and non-deterministic that process is.

That’s bullshit: complexity doesn’t imply non-determinism.  The closest thing to non-determinism you’re going to find outside of quantum mechanics (and to a sharp many-worlder that too is completely deterministic) is a physical system where tiny changes in initial conditions cause big changes later.   Butterfly effect; the Kirkwood gaps in the asteroid belt: chaos theory. You know the story.

Is brain development in humans like that? Do little changes in initial conditions generally, or often, eventuate in big differences later?  No: of course not.  Big changes usually leave you dead or seriously fucked up: selection hates that.  Development is robust because selection has made it so: generally small changes make no difference.  There has, over a long time, been selection for reliable development of phenotypes that work, have high fitness.  Obviously not always: shit happens, mutations happen.

One important example of that reliability of development : identical twins, even those raised apart, are very similar.  Turkheimer says that 10% of the time, identical twins have significantly different IQs: well most of the time matters more than 10% of the time, and most of the time identical twins are very similar.  Identical twins raised apart are more similar than dizygotic twins raised together.  Some of them are insanely similar.

I’m going to mention some facts from agricultural genetics – not because I think that people are sheep ( although they are), but in order  to make some points.

Lots of important traits in domesticated animals are highly polygenic. Milk yield in dairy cows is highly polygenic: no single allele explains a lot of the variance in milk production.  Does this mean that milk production is not predictable, or that it varies in odd ways  compared to traits that are monogenic or oligogenic?   No, that doesn’t happen: the consequences of polygenicity that Turkheimer expects don’t actually occur. If they did, much of agriculture would come to a screeching halt.  Speed in horses is highly polygenic: does that mean that development of running ability is a nondeterministic process?  Is it logically impossible to know that certain breeds or horses ( say  Thoroughbreds) are faster than other breeds (say  Shetland ponies)?  It may be logically impossible for Turkheimer, but it’s easy for everyone else.  Along the same line, Kevin Mitchell, for equally mysterious reasons, has said that it’s really hard to select on highly polygenic trauts – even though we have a mathematical theory of selection that says otherwise, even though we do it every day in agricultural genetics.

Both are making use of nonexistent general principles to further a particular conclusion.

Let me tell you a real difference in a highly polygenic trait compared to a monogenic or oligogenic trait: the highly polygenic trait is generally more predictable, not less.  Although quite a few alleles affect skin color, there are a few with large effects,  SLC24a5 for example.  Siblings will look a lot different if one has SLC24a5 and the other does not. This happens often in India.  Underlying principle: central limit theorem.  You’re throwing more dice.

Turkheimer also says that we don’t really know anything about polygenic differences unless we  understand the mechanisms.  And usually we don’t know the mechanisms: even when we know that a given allele boosts a horse’s speed, or a Guernsey’s milk production, or makes dachshunds have short legs, we usually don’t know exactly how  it works.  Often we haven’t the faintest. Which is why we couldn’t select for fast horses or cows  that produce lots of milk- except that we could and did, hundreds of years ago, thousands of years ago. You don’t need to know how a plus allele or minus allele for trait X works to be able to [reasonably] accurately predict the consequences. Investigating mechanisms is going to be difficult in highly polygenic traits: those alleles favoring high trait value could work through a number of different mechanisms.  We don’t  know the mechanisms involved in the behavior of Turkheimer’s dogs – but in that case it doesn’t bother him.  In humans, not knowing mechanisms bothers him: He wants humans to be special.  And hey, they are, but not in the way he would like.

Actually I don’t quite believe this of either Mitchell or Turkheimer. I think they’re trying to arguing away stuff they don’t like.

That said, although knowing the details of mechanisms is not usually essential, I can think of cases where it’s worthwhile. There is a haplotype, now common in dairy cattle, that significant boosts milk production in heterozygotes while being lethal in embryo in homozygotes.  Milk production went  up while calf production went down.

What about the idea that  some unknown small thing might cause someone with an identical genotype to be quite different?  Not impossible – but we know it doesn’t happen very often, since identical twins, even though raised apart, are on average very similar.  We know that genetically more similar people have more similar IQs. A robust development process, favored by selection, does this.

A note: we know that different races have significant average differences in behavior at birth.   

Turkheimer says that I think he doesn’t have the intellectual courage required t0 face unpleasant facts. I don’t know the man: I don’t know whether he has intellectual courage. A priori, it’s unlikely, because few people and fewer professors do.   But I do think he’s unsound on general questions in quantitative genetics, which is what I think of Kevin Mitchell – even though Mitchell just has a perfectly sound post on transgenerational inheritance. Once is not enough.


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76 Responses to Turkheimer speaks!

  1. Excellent post. The objection “we don’t know exactly how it works” would have been fatal to the electrification of society a century ago. Happily, they knew THAT it worked, if not exactly how. Just join up the wires.

  2. Coagulopath says:

    Also, see Steve Sailer’s response.

    Turkheimer’s website has a font where the 9 is dropped weirdly low. He kept saying “goth percentile” and I wondered what that meant.

    So the question is, to what extent is the relationship between human behavioral differences and our genomes like the relationship between dog behavior differences and their genome? The answer is: they aren’t alike at all. It’s a funny argument to make, because it involves pointing out a difference between humans and other animals, in a scientific world that for many good reasons emphasizes the similarities. Humans, of course, are primates with genomes that evolved pretty much the same way as other genomes did. But the relationship between our behavioral differences and our genetic differences is very different. The behavior of dogs is “significantly, innately” (if not completely) fixed by their genomes. My two golden retrievers love to swim, like all golden retrievers, and they didn’t need to be taught. Like many water dogs, they have webbed paws, an actual biological adaptation, a mechanism, for swimming. My old hound dog wouldn’t jump in the water on a bet. That is part of being a dumb dog—they don’t make choices about that kind of thing.

    I’m beginning to think it’s a bad idea to ever use an analogy in a debate. This is always the response. They get interpreted literally.

    Greg used dogs to illustrate where Lewontin’s theory fails. Turkheimer reads it as “dogs and humans are exactly the same in every way”, which obviously wasn’t the claim.

    Dog breeds are more phenotypically distinct than human races (Misdreavus once said that some breeds are 10SD apart in certain traits, vs 1-2 for races. Does that sound right?), and have been artifically selected in a way that humans haven’t. But most of their differences are within-group rather than without-group, and thus Lewontin predicts they should be different. We’re not saying dogs are like humans.

    Do people realise that analogies have a specific element of comparison? They’re not statements that Example A is equal to Example B right down the line.

    Greg: “human evolution has sped up in the last 100,000 years, like a car accelerating.”
    Eric: “cars have engines, and humans don’t! Your argument fails!”

    • Coagulopath says:

      Someone fix my a-link, please.

    • dearieme says:

      “I’m beginning to think it’s a bad idea to ever use an analogy in a debate. This is always the response. They get interpreted literally.”

      Au bleedin’ contraire. It’s a good idea to use an analogy in a debate because if it gets interpreted literally your opponent has revealed himself to be a knave or a fool.

      • Greying Wanderer says:

        the dog breed analogy is great cos it forces them to be openly dishonest

        • The Z Blog says:

          Dog breeds are a social construct.

        • Jesse M. says:

          Aren’t the specialized behaviors of different dog breeds, like directing the motion of herds of prey animals or freezing and “pointing” at prey, ones that were already part of wolves’ hunting behavior? Aside from being less fearful around humans (probably related to their more able to take direction from humans), and retaining some characteristics of juvenile wolves like barking, is there any good evidence against the hypothesis that the behavioral differences between dog breeds are just a matter of some aspects of wolf behavior having been lost or suppressed by artificial selection?

    • Mcat Bone says:

      Old style or non-ranging numerals, they are designed like a lowercase alphabet, with ascenders and descenders. The zero and 1 and 2 are the size of a lowercase x, the 3, 4, 5, 7 and 9 have descenders, the rest ascenders. The numbers run in with text more gracefully, good for literary uses, less so for scientific content.

    • Steve Sailer says:

      Here’s a question about dogs: My vague impression is that in the various parts of the world where people can’t be bothered to breed dogs, the dogs all wind up looking pretty much the same: somewhere around 35 pounds; shortish, yellowish fur; pointy nose. Sometimes this apparent default is called a poi dog.

      Apparently, the environmental differences in places where humans are kind of lazy about dog breeding aren’t so big as to make the default dogs look quite different. (On the other hand, most of these places are in the tropics, so the environmental differences are not that radical.)

      What does this suggest about human races? (I don’t actually know, but I hadn’t thought about this analogy before, so I just wanted to bring it up.)

      • moscanarius says:

        It suggests an explanation for why Sub-Saharan Africans look similar to Melanesians, Papuans, and Australian Aboriginals, despite being genetically distant from them.

  3. Greying Wanderer says:

    he says in his post

    “and in fact all concerned appear to agree: groups of people, defined geographically or phenotypically or ancestrally or however you want, differ to one degree or another in their gene frequencies. No one argues with that.”

    i argue with people who deny that all the time – cos it’s the mainstream view promoted by a dishonest media and academia


    “Comparing groups of humans to breeds of dogs is perhaps the laziest analogy in the history of human behavior genetics. It’s what high school kids write me about when they first become interested in the subject.”


  4. At least he says (in another post) what could change his mind on this…
    Oh, we have some of this already: MAOA 2R allele where there there is some understanding about role of serotonin in brain.
    There is no well-understood mechanism for oppression resulting in lower IQ scores. Same statistical correlations which he bashed for genes now prove causal link, because he likes it.

  5. William H. Stoddard says:

    Some years ago I looked into what was known about the functioning of the eye. At that time, it was reported that the eye showed measurable responses in retinal neurons to single photons—but that it took several photons to trigger a neural impulse. This seemed to be acting as a noise filtering process: one photon could come in by accident, but if you get half a dozen it’s a signal. That gave me some doubts about the idea that hidden quantum mechanical processes in the brain explain consciousness and/or give us “free will’; a lot of those processes would be a kind of noise (not meaningfully correlated to anything) and the brain would likely work better if it filtered them out.

  6. gkai says:

    Is this Turkheimer guy well known in the US? I wonder because I found his piece quite poor: usual arguments exposed in a wordy and confuse way, neither convincing nor entertaining. So I wonder why taking the time for an answer…

    • Rodep says:

      He’s the genetics-and-IQ researcher who tows the party line. He’s a lot of people’s go-to for lending scientific weight to their political arguments. Vox gets him to write an article everytime race and IQ is in the news.

  7. ThisCannotBeTheFuture says:

    Speaking of determinism, I recall Krauss complaining once that indeterminism in quantum mechanics is somewhat misunderstood: the evolution of the wave function is completely deterministic.

  8. ilkarnal says:

    I think you’ve missed one of the main points that is always brought up in these discussions, which is that we don’t know any reason for selection for intelligence to happen more strongly on one continent than another. Let me take a stab at it.

    It’s probably true that natural selection aims at the same intelligence in all places. There is a huge potential well, industrial civilization, which I think everyone would get sucked into eventually – or at least, that’s a reasonable guess. We can see the rapid march towards more sophisticated tools and guess that it would continue in any major lineage, even if it took longer in one than another.

    But taking as a given that the endpoint is the same, huge gaps may still emerge. To explain this, it is useful to drill down to the mechanics of evolution.

    When a beneficial mutation arises, the chance that it will become widespread is something like half of its selective advantage. If something gives you a 10% advantage and it exists only in you, it dies 95% of the time. Environment A and Environment B may both favor that mutation, but one may favor it less – for instance, because a high proportion of threats do an end-run around the advantage. If the mutation gives you a thicker skull to deal with sabretooths and clubs, in an environment that is the same except that crocodiles make for 20% of deaths, that mutation is less favored. Both places will still get there, but crocolandia will on average take more tries.

    Genetics is messy code – changing one thing often changes many things. Environment A and Environment B may both favor (trait++) but Environment B may be way more stringent about paying a price somewhere else. Let’s stay with the thicker skull – suppose that the mutation that gives you a thicker skull also screws up an innate defense to trypanosomes. Environment B has way more trypanosomes, and the selective advantage of the mutation is reduced or even reversed. Environment B has a mutation path towards thick skulls closed off. That doesn’t mean Environment B never gets to thick skulls – there are zillions of mutation paths towards improving a given trait. But all else equal, a more demanding and complex environment where more tradeoffs need to be balanced means a harder and slower route towards improvement at a given trait. When you’re on a knife’s edge and you need everything running perfectly smooth – where let’s say a delay in development gets you eaten much more often, a slowdown of running speed loses you crucial game, etc etc, it’s harder to change stuff.

    Natural selection can get you Eskimo cold resistance without the minuses Eskimos suffer to running speed. But it would get you that solution to cold slower than if it can use cruder, less sophisticated solutions.

    Mutations, beneficial or otherwise, arise through reproduction. Therefore, populations that are larger evolve proportionally faster. They just get in the necessary large number of attempts at making a beneficial mutation work faster than smaller populations. If one place supports a significantly larger population than another, then even if natural selection aims at the same endpoint for both populations (making them tall as trees, let’s say) it will progress much faster in the place that supports the larger population. Assuming hugeman phenotype is selected for, if someone from the large island with zillions of people walks over to someone from the tiny island with a hundredth the population after a long time has passed, he’ll be looking down at relative dwarves.

    To wheel back towards intelligence, the most intelligent populations are Eurasian. There’s a plausible explanation for this arising from the mechanics of natural selection – Eurasia harbors the most humans. The most intelligent populations come from places without too much competition from nonhuman predators and parasites, and given what we know about natural selection that’s not surprising. The most intelligent populations come from places where you’d see the most reward for long term planning – places where intensive high investment plow-based agriculture is used. Once again, we would expect this gap to arise from evolution.

    The question is thus answered satisfactorily – we know why populations would diverge in genetically determined intelligence in different places even if intelligence is very useful everywhere.

    • gcochran9 says:

      “It’s probably true that natural selection aims at the same intelligence in all places. ”

      It’s probably not.

      • dearieme says:

        I’d have thought that natural selection has consequences rather than having an aim.

        • gcochran9 says:

          Well, push a population into a new environment, in the short run phenotypic values will scootch towards a new equilibrium, in theory predictable if you knew the exact selective pressures, heritabbily, and so on.

      • ilkarnal says:

        Would it be good, all else equal, to have brilliant engineers in Africa? Sure it would. Eventually, once they are smart enough, it’s just as good as having brilliant engineers anywhere else – they make use of the resources available and create industrial civilization. But even before that, if it’s costless you might as well be smarter. If it’s advantageous and there’s no overwhelming barrier, natural selection should (very) eventually find a way.

        I liked my Eskimo cold resistance/running speed example. If you put grizzlies in a colder and colder place, they’ll probably get fatter and squatter at first. But very eventually, cleverer solutions will be found, and you’ll get the fairly svelte polar bear. You can get special heat trapping hair that doesn’t make you any squatter or fatter or slower without going through the squatter fatter stage. Doubtless such solutions exist for improving intelligence. They’ll just take longer to arise – as it took longer for the purloined Nepalese solution to high altitudes to arise than it took for the Andean mountain people’s more crude solution to arise.

        The story of bipedal apes is adaptation to take fuller and fuller advantage of the freed forelimbs. This adaptation is moving towards industrial civilization, inexorably. No matter your environment, being a little smarter for free means getting a little more mileage out of your hands. Solutions that are free or nearly free exist, they are just rarer than solutions that cost a teensy bit. And weaker selection and smaller populations means they take longer to get there. Much longer. But they’ll get there, if you give them forever.

        I suppose there’s the example of the flores hobbits. Maybe some environments turn you back into a monkey, but I don’t think any major chunk of the Earth is such an environment. And as you yourself alluded to, it’s likely the flores hobbits suffered from some issues that broke their brains a bit in a hard to reverse way.

        • ilkarnal says:

          Here’s a claim I would make – as long as you stay truly bipedal you’ll get to industrial civilization eventually. The drive to take advantage of free forelimbs with ever more advanced tools leads there inexorably, if extremely slowly under some conditions. However, if the environment somehow entices you back into using all four limbs for locomotion, you’ll be back in the trap that took hundreds of millions of years to escape. I don’t think it’s possible to both have the dexterity necessary for sophisticated toolmaking and use all your limbs for locomotion, otherwise some species would have gone and done what we did a long time ago. But I also don’t think it’s possible to have limbs free to do non-locomotion tasks without natural selection pushing you to take fuller and fuller advantage of those freed limbs. I suppose in some cases that means turning them into boxing implements https://imgur.com/a/3brMXYp or pincers https://imgur.com/a/cfZONpk but in the case of apes I think the inevitable attractor state is more and more advanced toolmaking.

          • gcochran9 says:

            “but I don’t think any major chunk of the Earth is such an environment” – the United States.

            • ilkarnal says:

              US dysgenics arise from non-Malthusian conditions, a self-correcting problem. Once you have apes fighting apes, and you eventually do, the apes that are better at fighting will proliferate at the expense of the rest. Eventually we’ll adapt around fertility reducing innovations. Part of that adaptation might be getting stupider for a brief while, but the pressure of being a better builder of ape killing devices will return and continue the inexorable climb.

              Maybe a disease will come along where the genetic solution reduces IQ 20 points. This can be thought of like the high altitude adaptation problem. If given long enough, the first cut adaptation will be refined to give the benefit without as much cost. The inexorable climb will continue. I can imagine lots of things that slow it down, not many things that stop it – humans dying out or somehow returning to branch-swinging and knuckle-walking locomotion are two of them. I think the concept of a favored phenotype that is inevitably approached is valid. If you see mammals become aquatic, if they stay truly aquatic inevitably they will become streamlined for efficient swimming. If you see apes become bipedal, if they stay truly bipedal inevitably they will become intelligent enough to take full advantage of their toolmaking hands.

          • Ursiform says:

            So the bipedal dinosaurs just weren’t around long enough? And we should be investing in kangaroo startups?

      • caethan says:

        For starters, if you’ve got a second, orthogonal, selection pressure in group A that isn’t there in group B, then the effective selection on anything else drops.

      • FactPrivilege says:

        Even if there is no max desirable IQ for any environment, the rate of IQ gain is affected by the relative reproductive advantage of IQ related genes to other desirable genes.

    • Jaim Klein says:

      There is a huge potential well, industrial civilization, which I think everyone would get sucked into eventually… Why would they? Evolution does not work by sucking in people … but by differential reproduction. And just now, industrial civilizations are being out bred by a wide margin by non-industrials, which show no signs of being sucked into outperform.

    • another fred says:

      Higher intelligence is correlated by larger structures in specific parts of the neocortex. While we all know correlation is not causation, it’s a pretty good bet in this case. Larger structures are biologically more expensive to support and maintain.

      Nature does not support biologically expensive structures unless they are accomplishing something, that’s why cave fish rapidly lose their eyes and birds that don’t need to fly (on an island, e.g.) don’t have the kind of wings that flying birds have.

      If a population is in an environment that does not highly reward high intelligence it will not develop high intelligence, and a population that moved from a demanding environment to a less demanding one would be expected to lose the expensive brain structures that support high intelligence.

    • JMcG says:

      I’m sure this is shorthand but the very key to natural selection is that it doesn’t, and can’t, aim at anything.

  9. Trukhedimer is trying to be both a liberal and a behavioral geneticist. Don’t waste your time on him.

  10. RCB says:

    “And without even a hint of mechanism, there is simply nothing we can say about whether you would still be smarter than me if some large or small difference in our life circumstances had occurred, heritability be damned.”
    Taken literally, this would imply that Turkheimer would refuse to believe in any genetic difference unless the biological mechanisms underlying the system were understood. Of course, that would require him to, in fact, deny genetic behavioral differences in dog breeds, which we don’t understand the genetic basis of. Does he do this? Of course not.

    But that’s not even the most bizarre argument here. His most bizarre argument goes like this:
    Humans are different from dogs and other animals, because animals are determined by their genotypes, while humans aren’t. Why? Because we humans have only moderate heritabilities, e.g. 50%, which allows there to still be plenty of behavioral variation even among twins! So, “human behavior is very malleable conditional on genotype.”

    (And, according to Turkheimer, it’s a difference of kind, not just of degree. Quote: “If the heritability of intelligence is .5, doesn’t that mean that humans are behaviorally constrained like dogs, just to a lesser extent? No it doesn’t.” Baffling…)

    Of course, nowhere does Turkheimer say what the heritabilities of behaviors are for dogs. My guess would be that they are in fact lower than human heritabilities, since dog breeds are more inbred than humans and therefore have less genetic variance to contribute to a trait. I know of no evidence to suggest that human behavioral genetics is in any way exceptional among animals.

    My impression is that a lot of this has to do with the fact that the blog post is hosted by the Genetics and Human Agency project. Dogs can be dumb genetic robots, but humans have agency, damn it!

    This is all a waste of time anyway, since the heritability of traits within groups says nothing about the differences between groups. Turkheimer probably “knows” this – in the sense that he can say that sentence at the right time – but he doesn’t appear to understand it.

    • gcochran9 says:

      When talking about agency, the first step is figuring out which humans are NPCs and which are players.

    • gcochran9 says:

      He wants to think that groups that have low average scores in, say, the US, might have high scores in some other environment. Over the existing range of environments, that doesn’t happen. Rank orders don’t change.

      Now I could construct such an environment, simply by hitting kids from high-scoring groups in the head with a pipe wrench.

      • caethan says:

        I’m confused, though, because his argument is that historical racism makes it impossible to create such an environment:

        the one new context we really need to observe, the one where slavery didn’t happen and the effects of racism have worn away, is impossible to observe

        So apparently non-existent and impossible environments are just as important as the environments that actually exist right now. I mean, if Monsanto tried to sell me a new corn strain and told me that it did very poorly in Iowa topsoil, but it would be amazingly productive on Venus, I’d probably mark it down as a bad purchase.

        • RCB says:

          It’s a great defense: assert that the only evidence that could resolve the question is impossible to collect. Cowardly, idiotic (somehow every country south of the Sahara is still reeling from slavery – but nowhere else), and even anti-scientific (to assert that the hypothesis is unfalsifiable), but it’ll buy him many years.

        • albatross says:

          The strongest form I can make this argument into is something like:

          a. Environments differ between racial groups in very complicated, subtle ways that are impossible to completely control for. Blacks and whites in the US, for example, differ not just in income and parental SES, but in a bunch of other stuff (average income of neighborhood, family wealth, family education level, lead exposure probability, region of the country, probability of parents being married, etc.).

          b. Because those differences exist and are very hard to control for completely, we can’t know for certain that observed differences in outcomes (height, IQ, personality, life expectancy, colon cancer rates) are due to genetic differences rather than some unseen but highly-potent environmental difference.

          c. If we had a known genetic mechanism that explained those differences in outcome, we could draw conclusions; lacking that, we’re stuck without the ability to conclude anything about the causes of those differences.

          Now, I think this argument is basically correct–we can’t conclude anything with absolute certainty. But in Bayesian terms, it sure seems like, having observed all the relevant data, we should assign a pretty high probability to the differences being largely genetic in origin. If we drew a graph where the X axis was “% of IQ difference explained by genetics” and the Y axis was “posterior probability given all this data,” it seems to me that Turkheimer is claiming that this graph should be flat–it’s equally likely that it’s 0% or 10% or 50% or 100% genetic. He knows the field a great deal better than I do, but it sure looks to me like the graph should probably be skewed rather strongly toward a largish fraction of the difference being genetic in origin.

          Similarly, for predicting the future, I think almost nobody looking at this data would make predictions that were consistent with “nobody can say anything about whether these observed differences are genetic or not.” If you had to bet your retirement account on whether there would be any sub-Saharan African country or majority-black Carribean country that would become a major scientific/technological powerhouse in the next 50 years, what odds would you require to take the “yes” side of that bet? Or if you had to bet on whether the black/white gap in school performance would disappear in the next 50 years?

          My impression from other comments he’s made is that he feels that it’s irresponsible to speculate that genes may be the cause of the IQ gap without hard evidence. And that seems like a defensible position, even though I don’t totally buy it. But this “we can’t really know anything at all till we have 100% absolute ironclad evidence” bit seems to me to be a pretty classic isolated demand for rigor.

  11. Mcat Bone says:

    Several errors, all of which a spell check will catch.

  12. Stephen says:

    Wishing to be fair, I looked up the Turkheimer paper that was cited.
    I got as far as “if two groups differ on a single nucleotide (I used trisomy and Down’s Syndrome in my example) that has large and invariant consequences for an outcome, it makes perfect sense to say that the two groups are (in Cochran’s undefined terms) “significantly, innately” different”.
    Any self-proclaimed geneticist who honestly thinks that Down syndrome is a consequence of a single-nucleotide difference, or that trisomy involves such a difference, has disqualified himself from any serious consideration.
    May he meet with the ridicule he deserves.

  13. SlushFundPuppie says:

    Never trust a Turk.

  14. Warren Notes says:

    I’ve had false pride I hadn’t been indoctrinated. So called “professional courtesy” and fears about publication, hiring practices, etc. usually prohibit openly calling out others, no matter how badly mistaken they are. I now wonder much progress has been hindered by that.

  15. David Chamberlin says:

    I expected the Turkheimers of this world to ignore and shun Cochran for another decade or two and not to be drawn into debating him. Maybe progress is being made. I love following these scientific quibbles, here is one comment Turkheimer made I want to respond to.

    “Cochran is infuriating because he doesn’t feel the need to argue his case on the merits. He assumes that the facts are obvious to everyone, but only he has the intellectual courage to face them:”

    I think their lying eyes are getting weary of flat out denying that countries with terrible average IQ scores are always third world poor and desperate and those countries with high average IQ scores are doing quite well. As a millennial JamesDW said a few posts back ” My generation isn’t completely retarded like boomers are–and boomers are dying.”

  16. savantissimo says:

    Surprised you didn’t point out Turkheimer’s math (and arithmetic) error in the expected IQ difference between identical twins (10.58 points, he claims). That’s measured, and he’s wrong. He used the wrong formula, plugged in the wrong number for heritability, and then did the arithmetic wrong (off by only 0.25%, but computing 4 digits with a heritability number he pulled out of the air is a sin itself).

    I believe the right number for the expected reared-apart MZ twin IQ difference would be (1-0.71)*15 = 4.35, and part of that would be spurious since the test-retest correlation for the same person taking the same test is less than 1. I might be using the wrong formula myself, though.


    A reference for IQ correlations between different degrees of family relations from “Genetics of intelligence” by Deary, Spinath & Bates in the European Journal of Human Genetics (2006)Table 2: Summary of the review of the world literature on IQ correlations between relatives with different degrees of genetic and family rearing overlap (from Bouchard and McGue, 1981)
    (Removing the sample sizes and putting the correlations first so it can be read without tab formatting:)

    Weighted average IQ correlation / Relationship (environment – living together or apart)
    0.86 Monozygotic (MZ) (together)
    0.72 MZ (apart)
    0.72 Midparent–midoffspring together
    0.50 Midparent–offspring together
    0.60 Dizygotic (together)
    0.47 Siblings (together)
    0.24 Siblings (apart)
    0.42 Single parent–offspring (together)
    0.22 Single parent–offspring (apart)
    0.31 Half siblings
    0.15 Cousins
    0.29 Nonbiological sibling pairs (adopted–natural pairings)
    0.34 Nonbiological sibling pairs (adopted–adopted pairings)
    0.24 Adopting midparent–offspring
    0.19 Adopting parent–offspring
    0.33 Assortative mating

    • RCB says:

      He might have used too-low of a heritability, but the math was otherwise correct. Heritability refers to the proportion of the variance explained (statistically) by genes. The variance is the square of the std dev, which is 15. So the variance unexplained by genes is, in his case, 0.5(15^2). The square root of that is the std dev in phenotype even among identical twins, which is approximately the average difference between them. sqrt(0.5(15^2)) = 10.6.

      If the heritability is 0.75, it’s 7.5. If the heritability is 0.9, it’s 4.7.

    • David Chamberlin says:

      Vile horrible links. They don’t need to be removed, it’s instructive to know that people like this still exist and have followings. Hate is real.

      • G.M. says:

        Such typical, low-effort psychopathologisations & accusations of “hate” are weak & constitute no rebuttal.

  17. Anon says:

    Turkheimer ended his piece with a comma. Maybe we should be charitable and assume he forgot to add in an actual argument before hitting “publish”.

    • gkai says:

      Good one!

      • Anon says:

        It is not Greg Cochran who lets his policy preferences color his view of science. It’s Turkheimer, and the fact that his view of the world is one that motivates him to put the word “just” in italic only makes it worse,

  18. Jim says:

    I have often come across arguments that contrast complex emergent traits such as behavior with traits that can be tightly connected to a very specific and localized site in an organism’s genotype. The implication seems to be that somehow such complex emergent traits are not really genetic. But of course most biological traits are complex emergent traits. Locomotion which is a pretty obvious trait of animals is a complex emergent trait but that doesn’t mean that the movements of a squid have nothing to do with it’s polynucleotides.

    In fact virtually all macroscopically observable traits whether of organic or non-organic beings are complex emergent traits. For example the liquidity of water under typical terrestrial conditions is a complex emergent trait. Water molecules in themselves aren’t liquid. Nevertheless the liquidity of water under typical terrestrial conditions is explained by the structure of water molecules.

    As for the argument that until we understand the exact mechanisms involved we can’t suppose that something is genetic that would imply that the work of people like Darwin and Mendel was pseudoscience since neither knew anything about such mechanisms. At the time that Darwin wrote “The Origin of Species” nucleic acids hadn’t even been discovered.

    Humans were able to use fire in all kinds of useful ways many, many thousand of years before anybody had heard of oxygen.

  19. syonredux says:

    Eric Turkheimer: “That is part of what makes the argument so gross,”

    Why do grown men nowadays sound like ’80s Valley Girls?

  20. pyrrhus says:

    Even a Harvard Professor should be able to understand these points…But Turkheimer is making sure that he stays at least two steps ahead of the lynch mob that is the current Harvard faculty.

  21. Yudi says:

    Let’s pick through Turkheimer’s post. Let me say here that I don’t mind Turkheimer and his group, really. In fact, as the only leftists who talk about heritability at all, they form a valuable part of public discussion. I wish he’d stop implying hereditarians are evil, though. Flynn is an environmentalist too and he doesn’t do that.

    “groups of people, defined geographically or phenotypically or ancestrally or however you want, differ to one degree or another in their gene frequencies. No one argues with that.”

    Lots of people do. Look how David Reich’s discussion of it in the NYT was received! It’s almost as if a generation of teaching that “race is a social construct” in schools has left people unprepared for its reality.

    “My two golden retrievers love to swim, like all golden retrievers, and they didn’t need to be taught. Like many water dogs, they have webbed paws, an actual biological adaptation, a mechanism, for swimming.”

    Did those webbed paws come about through a single mutation? Or are they a complex trait too? In that case, their function ought to defy analysis until we’ve found which genes are involved and their causal mechanisms! Also, dogs liking water is definitely a complex behavioral trait…

    Speaking of adapted mechanisms for swimming, did you hear that news about the Bajau? And differences in alcohol metabolism surely play a role in how societies deal with alcohol problems. That’s a lot of human suffering and inequality explained by clear genetic pathways right there. (NB: this is my pet HBD topic).

    Aside from this, like Turkheimer I am hesitant about using dog breeds as an example for how human races work. It’s too easy to counter with how selectively bred they’ve been compared to any human groups.

    “And without even a hint of mechanism, there is simply nothing we can say about whether you would still be smarter than me if some large or small difference in our life circumstances had occurred,”

    Like some other things in the piece, this point is valid but not very useful. We have the range of environments that are possible on Earth, with the human species and its technologies as they are, not the whole range of possible environments in the universe. It doesn’t much help the disadvantaged to say this.

    I don’t know enough about Turkheimer’s discussion of twin differences to judge the usefulness of it.

    “What a well-intentioned hereditarian ought to be doing is searching for a mechanism of that kind, and some of them are; more power to them. I don’t think they will be successful but I have no fundamental problem with the effort.”

    Well, the best way to find clear genetic mechanisms for intelligence would be to look at the nature and causes of Jewish intelligence, since they are a small, recently-formed high-IQ group with some well-known mutations. Cochran has looked at that himself! Progressive gatekeeping in this area of research isn’t a problem at all, right…?

    “Think for a minute: why do we hold someone responsible for their criminal behavior, but not for the texture of their hair? Hair texture is determined by our genes; we don’t have any choice about it, and groups of people with a certain kind of hair just are the way they are. There is no ethical content to hair texture, no hope that things will be different someday.”

    Appearance is far easier, and cheaper, to alter than IQ. We don’t judge hair texture in the present time because we don’t credit it with a causal effect on behavior. But plenty of past societies did use hair texture and other racial characteristics to judge people, so it’s certainly possible to build an ethical system around it, even if it’s an unlikeable ethical system.

    It’s curious that he goes on to mention that the criminal justice system is wise for judging behavioral traits on the basis of free will because of their complexity or whatever. My hereditarianism and knowledge of history have turned me against this very view! I don’t think that the habitual criminals who make up a disproportionate number of convicts really can control their habits well, certainly not as well as the rest of us. But states have learned over the past 5,000 years to punish these misfits in public in order to scare everyone else into good behavior. That’s not an ethically pure strategy, it’s a solution that has ended up working well. In fact, I think it’s sad that we must essentially sacrifice the crime-prone so that the rest of us know not to hurt each other. If we could find ways to help the criminally inclined be less so (including genetically-based ones) this would be a wonderful reform.

    ” the human central nervous system, the greatest engine of anti-determinism ever designed by evolution, is interposed between genotype and phenotype.”

    Turkheimer himself mentioned that hitting someone in the head with a brick may cause them to become less smart. Sounds pretty deterministic to me.

    “the heights of many populations have increased by more than three inches in the last 100 years”

    But those pesky within-group differences are still there. Ask short men how much they like it.

    “the fact that his view of the world is one that motivates him to put the word just in scare quotes only makes it worse,”

    What Greg put in scare quotes is the idea that only current, predominantly gene-denying progressives have a monopoly on what constitutes a just society. All of us hereditarians are sick and tired of being used as stock benighted heathen in order to make yourselves look better by contradicting what we say.

    tl;dr: Turkheimer is good at putting his ideas down and makes some effective points. But he wants to judge human behavioral traits as special compared to those of other organisms, which is a type of creationism. Greg is the true evolutionist here, and he’s a Christian!

    It’s sad when intellectual lightweights like me, unimportant people with no scientific training, can compete in discussions of race and behavior with the professionals. But that is what happens when those who should be in the know about these matters have defaulted on their responsibilities to the scientific community and the public by wholesale denial and worship of ignorance. (note: I am not referring to Turkheimer here, since he at least talks about it, but to the Western scientific community as a whole.)

    • Anuseed says:

      Greg’s a Christian? LOL WUT?

      • Zenit says:

        Indeed. It will be interesting to watch our esteemed host to square belief in evolution with belief in all-powerful, all-knowing, all-loving God.

    • Anon says:

      “Let me say here that I don’t mind Turkheimer and his group, really.”

      Why do I always see this qualifier? You should mind. Nothing is gained by being respectful to these people beyond common decency. Would they return the favor? If not actively hoping for it, people who willfully obfuscate group differences like Turkheimer would be totally fine with you, yours, and everyone like you losing their professional careers for investigating this topic. They are liars and should be regarded as such.

    • gkai says:

      Shying away from using dog bread because they are artificially selected is not a good thing. It’s a typical creationist distinction, and a very old one…in fact, Darwin achievement was realising that artificial selection and natural selection is just the same: differential reproductive success based on heritable characteristics.
      Another typical old position is the “in animals yes, but human are special because…” .
      Basically the Turkheimer post recycle beaten-to-the-death creationist arguments. How funny that US liberals seems opposed to hereditarians while simultaneously mocking creationists, not realizing they are creationists on human behavior/iq topics.
      Funny but not really surprising: maybe I miss something (English is not my native language), but Turkheimer seems to completely miss the sarcasm in Greg’s ladder “skin pigments, hair type….and fast twitch muscles, none density, …” and take it like an acknowledgement that race concern only trivial details…
      The problem the official doctrine face is that, as an equalism, it is in an indefensible corner: it require that group average to be absolutely equal on IQ. Not allowing even slight difference put you in an indefensible position, so we see a lot of stupid arguments and even more obfuscation…and also some preparation to abandon ship by the more clever, like Reich, but you have to be careful as the inquisition is never more rabid than when the boat is sinking…

  22. GAGCAT says:

    There are plenty of variants that lead to behavioral change – lookup autism susceptibility in OMIM or ClinVar.

    An experiment I’d love to run is homozygosity percent of a genome and clannishness.

  23. Toddy Cat says:

    Turkheimer and Mitchell are classic examples of basically intelligent men trying to defend basically stupid positions. See also “Intelligent Marxists”…

  24. Reading these comments about what he has written, Turkheimer seems to be following a well-worn path. He gives a list of reasons for believing that evolution applies to dogs, people and all living things and then, at the last moment veers off into a protective obfuscation. It is as if he would like to confess all, but at the last moment screams: “I am innocent, I really am!”. OK. I wish those on the other side of the argument were allowed to use that defense. When James Flynn said to me “I know I am on the side of the angels” he was mocking the mere thought of it. Turkheimer seems to be saying it for real.

  25. jb says:

    It’s not surprising Turkheimer aggressively dismisses the dog breed analogy (as “lazy”), because it is in fact very persuasive. Just two comments here:

    1) Turkheimer states that dogs “have been systematically selected … for many thousands of years.” Well I suppose some have, but others breeds are only a few hundred years old, if that. Breeds can change very quickly, and this includes changes in polygenic traits.

    2) The differences between dog breeds are much larger than the various purported differences between different human races. For example, with intelligence (the only difference anyone really cares about!), we are talking about maybe a one standard deviation spread between Europeans and Africans. That’s really not much in absolute terms — comparable to a mere three inches in height.

    So the point of the breed analogy is not that dog breeds are precisely equivalent to human races. What dogs tell us it that very large changes in complex polygenic traits can happen very quickly in large mammals. Once you know that, it becomes much more difficult to rule out the possibility that over a long period of time smaller changes might have arisen between various human populations.

    But the primary focus of race denialists is precisely that: to rule out, a priori, even the possibility such differences. If I were debating Turkheimer, rather than trying to win the debate outright, and prove that significant racial differences existed, I would focus on trying to force him to acknowledge that that, given what we currently know, such differences are at least plausible. Such an acknowledgement is blasphemy on the Left, so i suspect he would refuse to concede even that much. And that would be a much easier argument for me to win.

  26. Patrick L. Boyle says:

    Some people seem to gravitate towards genetic explanation while others embrace environmentalism. I’ve always been partial to genetic explanations. The reason was probably my home environment.

    My mother was an identical twin. She and her sister grew up together, moved to Washington together and worked at the same company. They each married about the same time and almost simultaneously had one male baby. They divorced also simultaneously and moved into together essentially for the rest of their lives. They never lived more than five miles apart and for most of the time in the same house.

    So they had identical genetics and virtually identical environments. They were very, very similar. One would start talking and the other would finish the sentence. It was a little creepy. It was like a vaudeville act or one of those sci-fi stories about hive minds.

    I grew up in a sort of natural genetics experiment.

  27. Dana Thompson says:

    The similarity of twins raised apart is often cited to support the notion that heredity is responsible for subtle and complex nuances of personality and aptitude. Why is it not equally noticed how often non-identical siblings raised in the same environment are radically different? Doesn’t it lead to the same conclusion, and moreover is much more within people’s common experience?
    As for me, I take the idea that genes dictate every aspect of personality to the furthest extreme imaginable. As an amateur genealogist, I have on occasion noticed cases where one of my first cousins resembles a second cousin, physically and/or in personality, more than any of his first cousins. To explain this, I invoke the mental image of a pinball machine, mounted vertically, with a steady rain of chromosome fragments (“pinballs”) flowing down the various lines of descendancy and being deflected right-or-left by bumpers (“conceptions”) and ending up in a row of bins (“cousins”). My pinballs marked “personality” are more likely to be deposited among my siblings than into any other family, but nonetheless, given the simple mathematics of the binomial distribution and the potentially large number of my first, second, third, etc. cousins, I’ll guess there’s a non-trivial probability that a large blob of my personality has landed with a splat on at least one of my hapless kinfolk. In fact, I have an uncanny sense of being an intellectual doppelganger to one of my third cousins (based on my reading of his website). He’s a noted astrophysicist, and I’m an obscure cubicle wart in a government office, but that’s the butterfly effect for you. Damned butterfly probably pissed in my face when I was little, but nonetheless, I am what I am.
    While I’m at it, why are we (“we” being everybody but me) so fixated on the meanderings of our ancestors 10,000 years ago? Aren’t they like the people that Orson Welles viewed from the top of the ferris wheel, i.e. ants detached from human sympathies? In a few decades, people will wonder about our ant-fixation and ask why we didn’t explore the interesting aspect of genetics, i.e. what locations on what chromosomes are the abodes of our innermost sense of self.

  28. jody says:

    he’s just a jewish guy trying to make sure gentiles don’t notice patterns or think forbidden thoughts. it’s no more complicated than that. there’s been lots of these guys over the last 100 years.

    want to save yourself a lot of trouble? whenever some guy starts talking like this, check his wikipedia, or just google (author’s name + jewish). whenever the expected result comes up, as it usually does, just put that person on the permanent ignore list. problem solved. don’t even bother reading or listening to what he has to say.

    no need to do multiple part rebuttals the way greg has done three times now just in 2018 alone. for reich, zimmer, and turkheimer. unless you enjoy the practice and want to hone your skills and debate abilities. these guys don’t argue in good faith, so you’re wasting your time doing it for any other reason.

    hysterical women making nonsense arguments about these topics can always be ignored, of course. you don’t have to check who they are, as they are all equally clueless. they almost never know what they’re even talking about in the first place, and aren’t arguing in bad faith, but arguing in estrogen.

    • The G_Man says:

      Whoa! I’ve never considered the possibility that Jews might be over represented among prominent left-leaning intellectuals. This has completely shattered my prior worldview.

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