My review in the Washington Post of a new book on genetics and social justice

November 19, 2021 • 9:45 am

Today the Washington Post put up online a review I wrote a while back on Kathryn Paige Harden‘s new book, The Genetic Lottery: Why DNA Matters for Social Equality. Click on screenshot to read my take, or make a judicious inquiry if you can’t access it.

Harden is a behavioral geneticist and Professor of Psychology at the University of Texas at Austin. You may remember that The New Yorker had a long profile of her a short while ago, and in it was this statement by her grad school mentor Eric Turkheimer:

In Bozeman, Harden seemed anxious that she had not heard from Turkheimer about her book. It took him a long time to get around to reading it, he told me, in part because of the ways their ideas have diverged in recent years, but when he finally did he wrote her an e-mail that said, “I really do think the book is great—in fact I think it will be instantly recognized as the most important book about behavior genetics that has ever been written. You should get ready to be very famous.”

Turkheimer has beefs with some of Harden’s ideas, but I simply had to read a new book about genetics that was likely to make its author very famous. And so I got the book and read it, and the Washington Post asked me to review it. Click below or go for that judicious inquiry.

As you see, my review is mixed. Her explanation of genetics and the use of “genome wide association studies” (GWAS)—a way of determining the expected value of a phenotypic trait from sequencing an individual’s genome—is excellent. She’s a good writer. The problem with the book is that she tries very hard, despite being somewhat of a genetic determinist who sees most human variation as having a sizable component of genetic underpinning, to appeal to the Progressive Left. For Harden is “woke”, as they say, and she’s aware that the other side, conservatives, would love to hear the sizable contribution to the variation of IQ of attributable to variation in people’s genes (it’s about 40-60%). There are large contributions of genetic variation to many other human traits as well.  But Harden carefully explains, correctly, that genetics is not destiny and that even a high genetic component to variation of a trait doesn’t mean that this variation can’t be flattened or equalized (I use myopia and glasses as an example).

But she’s still left with the problem of reconciling genetic inequality with societal equity—in particular how to treat children in school whose variation in academic achievement has a sizable genetic component. And here, in the prescriptive part of the book, she comes a cropper. She offers no plausible solutions about how one can actually use GWAS scores (I explain them in my review) to level the playing field for low achieving students, including minorities like blacks and Hispanics. (She doesn’t favor “tracking” students as she thinks that only perpetuates inequality.) My own conclusion is that, at present, we have no way of connecting GWAS scores to ways of improving education. It’s even worse because we know the genetic contributors of academic achievement only in European populations, and they could differ, as Harden emphasizes, in other populations. My conclusion:

I happen to share much of Harden’s ideology, and I wish her well. As I noted earlier, both the right and the left will find much to object to in this book. The resulting fracas might have been useful had she achieved what she set out to do — establish the fact of genetic unfairness and develop prescriptions to overcome it — yet she does not deliver on her second goal. Harden’s book is a thought-provoking read but in the end demonstrates only the incredible difficulty of using empirical data, both genetic and environmental, to level the educational playing field.

I want to add one thing here that was left out of my review for lack of space. Harden feels that we must rely on genetics to create equality/equity because one’s genetic endowment is a matter of “luck”:—the combination of genes you happen to inherit from your parents.  And Harden claims that she, and many others, feel it’s especially unfair for people to gain advantages simply because they’ve been genetically “lucky”. The implication is that there are things beyond “luck”, like an individual’s dedication and labor, that are a matter of “choice.”

This I find bogus, because, as a determinist, the “luck of your genes” is just as determined as “the luck of your environment” that also helps you achieve. Having the right for high IQ is “luck” in one sense, in that it’s not predictable, but so is the environment you’re born in and experience, which you also don’t choose. Harden actually recognizes this problem (p. 200):

Whether the universe is deterministic, whether such a thing as free will actually exists—these questions are beyond the scope of this book, to put it mildly. We need to put some philosophical guardrails up. If you think that the universe is deterministic, and the existence of free will is incompatible with a deterministic universe, and free will is an illusion, then genetics doesn’t have anything to add to the conversation. Genetics is just a tiny corner of the universe where we have worked out a little bit of the longer deterministic chain.

And, in fact, that’s the way it is. Harden has punted here. It doesn’t matter if you believe in “compatibilist” free will, because the philosophers who do are still determinists (or naturalists). And if you’re a determinist, then genetics is no more important than environment in its reliance on “luck” (i.e., unpredictability). It is just as unfair for someone to succeed because they had a good environment (and not necessarily good genes) than if they had good genes alone. Everything is determined—save the results of fundamental quantum unpredictability—which means that everybody’s fate is always matter of “luck” (unpredictable results of the laws of physics). Therefore, genetic and environmental influences are equally “unfair.” It is a major flaw of the book that Harden fails to take this seriously, but rather avoids it.

That’s all I want to add. The book is worth reading for its lucid genetic explanations, but I don’t think many hard-thinking readers will be convinced of her program to use genetic “inequality” to achieve social justice, though I agree that we need to do way better with schooling. Before you quibble about what I’ve said, though, read my review.

65 thoughts on “My review in the Washington Post of a new book on genetics and social justice

  1. I’ve long thought that early emphasis in the education system on the evidence that we all came out of Africa ~100Kyr ago is the best foundation for building the rest. Is that in her book?

      1. Thx, then far as I’m concerned, the book is seriously flawed. How can one write a book about human DNA without raising that aspect?

        1. Yay, semi-uumpulisive “bowser privacy hygiene” is as effective as judicious inquiry (or maybe that is what “judicious inquiry means?”

          Indeed, huge piece of analysis is missing from the book. If nothing else, don’t most evolution experts agree that humans continue to evolve? Maybe I’m revealing my ignorance, but it seems likely that human evolution has social consequences over generations. I am not a eugenicist, but pretending humans have stopped evolving seems untenable.

          Regardless of our differences in the compatibilitst – determinist dispute, I steadfastly agree with Jerry that we could and should do way with schooling. To me, doing better with schooling has to include increasing funding. The challenge & controversy though is funding policy that does good improving schooling.

  2. Thanks for bringing this book to our attention. I’m an avid reader (over 100 books since the end of February) so I love book recommendations.

      1. Thanks! I’ll put those on my list too! I don’t go out in public or to parties anymore since having had Covid – almost died from it. I don’t think I’d survive another infection, so books are my thing now.

          1. I was infected toward the end of May 2020 before there were vaccines or any types of treatments. The hospital basically told me they had nothing for me. I’m one of the long-haulers that sustained quite a bit of damage…it was a long recovery, but will never be back to my pre-Covid self. Oh well.

            1. In case it hasn’t crossed your window, Greg Zuckerman’s “A Shot to Save the World,” about development of the mRNA vaccines, might be of interest.

              Also, assuming that you were subsequently vaccinated, I’ve heard that vaccination generally improves the conditions of long-haulers. I hope that you were one of those.

    1. 100 books in around 8 months !
      How do u do it, are u a speed reader ?
      That’s around 3 books per week– an average audiobook is around 15/20 hours long

      1. Thanks, it works now. The subject is well above my pay grade, but a lucid, balanced and credible review to the extent that I am able to judge it.

  3. There was a study that you posted about some years ago, which unfortunately I can’t find, that concluded that ones’ success and chances for advancement tended to boil down to dumb luck. I recall that even the notion that a person could choose to pull ourselves up by their bootstraps was pretty much a myth since that character was one that some people are born with. “Chance eats everything” was a phrase that stayed with me.

  4. Yes, my sentiments exactly. Must admit that I gave up reading not too long after that paragraph you quote on p. 200. It struck me as dodging a very fundamental question by saying the issue is beyond the scope of the book. I live in one of the most equal (least unequal?) countries in the world – Norway – where Harden’s beliefs resonate. We just had an election where all the left-wing parties ran on variations of ´reducing inequality’. And it – worked; quite a big shift to the left. And the typical left-wing rhetoric reflects the same ‘luck’ explanation. Except that they moderate ‘luck’ by using ‘fortunate’. If you have earn/have more than the average person it’s because you’ve been more fortunate than they have. This perspective negates values such as hard work.

    1. This perspective negates values such as hard work.

      But, people who are hard workers are determined, just as those who are naturally lazy. “Luck” is simply expressing that fact. I suppose some folks could hear a leftist campaign speech and decide to work less hard, but that’s not too likely.

      1. If you’re a determinist, everything is “luck” in the sense that your fate is determined by the laws of physics. If you work hard, that’s because your unavoidable complement of genes and your environments turned out to enable you to work hard and make you want to work hard.

      2. Also, it is far, far from the truth that hard work leads to good outcomes. I have no formal numbers to offer, but over my lifetime I’ve seen more people that work hard and don’t achieve good outcomes than do. And I’ve soon plenty of people that don’t work hard and yet achieve very good outcomes.

        No doubt the characteristics of the society an individual is embedded in are a big factor. I think that’s the key issue. How to arrange our societies so that as many people as possible are able to realize good outcomes. Ideology and intuitions of moral correctness won’t lead the way forward in doing that. Any efforts will need to be very well informed by science to make any significant progress.

        1. And what is good?

          Many individuals have low income but have good outcomes (is this word fashionable or not?), maybe good genes but bad living conditions….

          Many individuals might have unfavorable X but favorable Y.

          But individuals do not get good or not-good things in a vacuum.

          You see where I am going with that.

          BTW the opening line is from Pirsig’s Zen and the Art of Motorcycle Maintenance. It has a follow-up but I’ll leave that for now…. or… it’s something like “and do we need others to tell us these things?

      3. One leftist campaign would not change anything, no. But what if children are taught this in kindergarten, primary school etc? The simple mantra, repeated by all the typical figures of authority around you during your formative years – that all those who are ahead of you – are just lucky. Even prominent left-wing politicians quote studies purportedly showing that high personal wealth is due to luck – not skill; not hard work. How would that affect your sense of agency? If we accept that the environment we are born into affects the way we approach life – and the values that we are taught must surely be part of this environment, then being taught that success is due to luck must have an effect on how individuals seek to reduce the gap between their own outcomes and the outcomes of others who have been more successful. It’s hard to find informative data on how this affects people. That’s why I mentioned the election results.

        In a country with one of the highest standards of living, lowest levels of poverty, and lowest Gini index scores on the planet, ‘we need to reduce inequality’ trounced every other issue on the ballot – even climate change. And every voter knew that ‘reduce inequality’ means the new government will increase taxes on the wealthy considerably. Income taxes, property taxes, dividend taxes, inheritance taxes etc. And the reason this tax regime is not only considered fair and acceptable – but turned out to be the deciding factor in the most recent general election, is that large personal wealth is not perceived as ‘earned’. It’s just luck.

        This luck rhetoric is not always specific on the sources of luck, but it usually hints at both social-economic environment and innate characteristics (although genes are rarely mentioned specifically). For example, an individual that has built a business by working hard, making sacrifices, and networking successfully etc., might be reminded that they should consider themselves lucky for being born with the characteristics that are required to work hard, make sacrifices, and network successfully.

  5. Unfortunately this does nothing to convince me the woke Left aren’t completely, irredeemably insane.
    They have gotten rid of Gifted and Talented programs in NYC because they are white supremacy”. The NAACP wants them gone everywhere for the same reason.
    Back in my middle eastern birth country when I participated in these programs I would have been absolutely shocked to learn they were “racist”.

    1. The current infatuation of the Ctrl-Left with “equity” reminds me of the society of Vonnegut’s “Harrison Bergeron”. Because it is impossible to elevate those who lack certain qualities, the only way to achieve equity is to dumb down the rest, by brutal methods.

  6. First of all, it is not at all clear that the universe is deterministic. Classical mechanics and quantum mechanics have non-deterministic features. Second, just because the universe is not deterministic does not entail that a theological entity called “free will” exists. Third, whether the universe is deterministic or not, and whether free will exists or not, there is voluntary behavior and involuntary behavior, and there is coerced behavior and consensual behavior. (Swimming versus breathing, contract versus robbery). Something true of person at birth (their genetic inheritance) can be distinguished from a voluntary behavior (labor) and a purported motivation for a voluntary behavior (drive), although obviously genetics probably impacts a person’s capacity to labor and to demonstrate drive.

    In some sense, the modern fashion of addressing the will is perverse. We have a notion of agency (I, an agent, signed the contract voluntarily), and the entire idea of duress is that another agent overcame my agency improperly (fraud or force). So if you wonder why I missed the test this morning, it could be because I overslept (ergo I am lazy or ill) or because I was kidnapped. This is important because the determination of who gets punished, and to what extent, is based on who is responsible for a certain result.

    We do this sort of thing with say a result on a SAT test, Bill got a good score on the SAT because he worked hard on the test prep. On the other hand, to say someone acted a particular way because of genetics or because they are a victim of society, it is actually a categorical difference. Genetics has no agency, nor does society (although persons sometimes claiming to act on behalf of society are agents). If at baseline, the universe is ultimately, on the physical level, deterministic, it would not matter for purpose of the voluntary/involuntary/consent/coercion concepts, although it would be rather weird if you could predict what someone would do on a random task in advance.

    1. My thoughts are similar to KD’s last 2 paragraphs. As Jerry keeps pointing out with respect to legal punishments, you don’t have to believe in libertarian free will to see the sense in sending certain people to jail based on their choices. It seems obvious to generalize that to other incentives and disincentives. Is the idea to go ahead and give those incentives and disincentives, and to say that this is the right policy, but still to deny that people deserve them? Why?

      On Harden’s quest for equality: suppose GWAS’s show that certain genes/SNPs impair intelligence. Then we can try to come up with gene therapy for those genetic traits. Or we can try to trace the biochemical pathways that create the problems and counteract those mechanisms.

      1. Basically, there are two questions:

        Who is responsible?
        What is responsible?

        They look similar on paper, but the way people go about determining who is responsible versus what is responsible is as different as a jury trial is to an epidemiological study. Totally different anthropology.

        When we talk about will, when we are talking about agency, it relates to the question of who.

        When we talk about genes, society, and environment, it relates to the question of what.

        Even if we could answer the question of what is responsible for everything, the question of who is responsible would remain. This is the so-called problem of free will.

        1. Is this why people are uncomfortable with self-driving cars? Even if they could be made to kill fewer people than human-driven cars do—maybe they can already, for all I know—when a fatal crash did occur our sense of justice would require that a person (a who), not a thing (a what), be held culpable or at least responsible for damages. The corporation that built the autonomous car is a person and can be sued (and can sign insurance contracts to cover the liability for crashes) but we still would find it unsatisfying to be unable to blame “the nut that was holding the wheel” when the crash occurred.

          1. Its an interesting point, because if you look at auto regulation and airline regulation in America, the focus in airline safety was determining what went wrong, and putting changes in procedures in place to prevent it from happening, which was highly effective in significantly reducing fatalities. In contrast, you have auto regulations but no one is looking at what caused the fatal crash and trying to reverse engineer things to prevent another one, its throw the drunk in prison or the equivalent.

            I believe somewhere in Scandinavia, they adopted the “what went wrong” approach to traffic fatalities and I believe it has been very successful at reducing deaths.

            1. Ultimately, personal responsibility, “who gets spanked for this outrage” can only be understood sociologically. The one who is at fault gets tagged with a judgment or enjoined or imprisoned or executed by the state. When you don’t have state action, it is your vigilantes against perceived the free-rider. I hate “free will” but to the extent that we want to talk about it, “free will” is a sociological concept and only exists in certain kinds of human societies and relates to how those societies mete out justice to members of those society. It has nothing to do with biology or physics or metaphysics, although it requires a specific biological/physical platform (namely humans) for it to function in a meaningful way.

      2. Each gene has very, very small effects, so gene therapy would not be at all useful. The best and fastest solution is figure out your goal and then change the educational environment to best achieve it.

    2. Sorry, but in what sense is classical mechanics indeterministic? And, as I’ve written often, I don’t give a rat’s patootie if quantum mechanics isn’t deterministic because it still doesn’t give us any agency. I agree with you on the definition of responsibility, but I don’t agree with Harden that genes are what we need to address for equity because they are due to “luck” while everything else is due to will.

      1. “in what sense is classical mechanics indeterministic?”

        Because of chaos, in the mathematical sense. Take the planets of the Solar System moving under the force of gravity, for example. We cannot accurately predict their positions beyond a few million years into the future, and we do not know whether the Solar System as an ensemble is stable on timescales of many billions of years. This has been known since the time of Laplace, and is still an active area of research. There’s a good summary of some recent work here: https://www.sciencealert.com/our-solar-system-is-going-to-totally-disintegrate-sooner-than-we-thought

        1. Sorry, but chaos theory is completely deterministic, and everyone knows that. Just because you can’t predict something does not mean that it’s not deterministic. I’ve written about this extensivey on this site, but you don’t seem to realize that you’ve erred here.

      2. When you crack three or more rigid objects together simultaneously, you don’t have a predictive results as to what will happen. They can spin off at different angles and speeds, even though conservation laws are preserved. There are other examples:

        http://dsbaero.engin.umich.edu/wp-content/uploads/sites/441/2019/06/BhatIndeterminacy.pdf

        As far as agency, we surely have agency, or you and I couldn’t debate the existence of agency. It can’t contradict the laws of physics because we have a social agreement on the concept of agency and we all know how to use it. If it didn’t exist, I don’t know how you could teach a child the concept of agency. As to how a particular species of language-using primates can have and develop a concept of agency and how that relates the the biology and physics of those organisms, I can’t claim to have the slightest clue.

        I know you are committed to determinism, but are you saying you couldn’t serve on a jury on a rape case because you don’t believe in consent? I believe that you could distinguish between a situation where there was consent, and where there was force, even though there may be gray areas.

        1. I don’t see any problem with voluntary acts. That is pretty much common sense to most people.

          I don’t like “free will” because its a mystification, you have “voluntary acts” because there this invisible “free will” that makes them voluntary.

          No, what we deem “voluntary” or “coerced” is almost always based on what is publicly observable (X was passed out on the couch) and never because we divine their invisible “free will”. We are talking about classifying behaviors and classifying contexts based on public criteria in which we see those behaviors, not something hidden in someone’s brain or their Cartesian mind.

        2. 1. Newtonian chaos is entirely deterministic, even though its outcomes are unpredictable.

          2. “If it didn’t exist, I don’t know how you could teach a child the concept of agency.” Consider that it’s easy to teach children the concepts (and even the real existence) of Santa Claus and other supernatural characters.

          And we have very strong “lived experience” of personal agency. We also have very strong lived experience of a stationary earth and moving sun.

          3. PCC(E) has consistently emphasised the difference between legal/social “responsibility” and libertarian free will “moral responsibility”.

          1. I don’t know what you mean. There are physical systems that can be described by Newtonian mechanics that have multiple solutions, e.g. any of those outcomes can take place.

            Additionally, you have nonlinear systems (so-called chaos) described by classical mechanics which have multiple equilibrium, and systems can oscillate between equilibria. You can’t predict where the system will be at a particular time, but you can guess where it will end up.

            Your point on agency seems to be that you can have a concept, but that does not make something exist. As far as Santa Claus, the existence of Santa Claus is falsifiable.

            The concept of agency is interesting, because there are empirical standards for determining agency. You have guardianship proceeds if someone is incompetent, and you have the insanity defense in law, as well as diminished capacity defenses. If you can empirically determine that someone lacks agency (or has a diminished ability to exercise agency), then it would seem to suggest that there is an empirical phenomenon of agency.

            On the other hand, I do not believe that agency “exists”, any more than numbers exist. You have a concept, its has a use, it doesn’t really matter whether it exists or not, the use is vital to complex human societies. I would compare it to fiat currency.

            I do not see any distinction between legal responsibility and moral responsibility. Written laws are downstream of unwritten customs, and “morality” relates to the informal sphere, and the legal sphere is just the codification of the moral sphere. While there are criminal laws that really lack any moral valence, much of the criminal laws are what they are because of people’s moral sentiments. For example, as moral sensibilities toward homosexuality changed, enforcement of criminal laws became lax, and ultimately the laws were repealed. Gay rights began based on articulating moral claims, and claims about moral responsibilities that challenged other moral claims as well as laws.

            1. A corporation is a legal person. Corporations have legal agency. Do corporations exist? Do corporations undertake voluntary acts? Does this mean they have free will?

        3. Okay, you’ve made four or five cmments in a row, clearly haven’t read what I wrote about determinism, and have gone wrong about classical physics being indeterministic. Now you insult me by bringing up a hypothetical rape case. OF COURSE I could serve on a jury; the object being to ascertain if the accused raped the woman. Rape means forced sex without consent. Whether or not someone consented to the other person was not a “free choice”, nor was the decision to rape, but that doesn’t mean that one can’t determine that the rapist did the deed, and for reasons I’ve described on this site before (but which you fail to grasp) deserves to be punished.

          Your arguments are muddled and in fact reflect an ignorance of determinism and my own position. I think you should take a break from this website for a bit and stop dominating threads when you don’t understand the issues.

        4. When you crack three or more rigid objects together simultaneously, you don’t have a predictive results as to what will happen. They can spin off at different angles and speeds, even though conservation laws are preserved. There are other examples:
          http://dsbaero.engin.umich.edu/wp-content/uploads/sites/441/2019/06/BhatIndeterminacy.pdf

          I read that paper to see if does indeed revolutionise Newtonian Mechanics. (Spoiler: it doesn’t.)

          The counterexample [to “Newton’s principle of determinacy”], given in Section 2, consists of a particle moving along a nonsmooth ([…] not twice differentiable) constraint in a uniform gravitational field. It is shown that […] the equation of motion possesses multiple solutions.

          That indeed appears to be the case (I didn’t verify the maths). But, the “non-smoothness” assumption is well outside the rules for the real-world application of Newtonian Mechanics. GIGO.

          But IANAPhysicist, so I may have misconstrued something.

  7. The review by PCC(e) is paywalled, but I suspect it is rather similar to a thoughtful, partly favorable review of the book I read in Quillette by Robert Verbruggen. The latter writes: “Harden writes that school curricula can be structured in a way that’s “equity-promoting” or “performance-maximizing.” But it isn’t clear what the best tradeoff between these two goals is.”

    Harden evidently want to appeal to the part of the ideological spectrum for which “equity-promoting” is the summum bonum, a historical goal (or mirage?) of the Left at least since the Diggers of the English civil war. The trouble with subordinating all else to equity-promotion is that it can go in an uncomfortable direction, the point of a Jewish joke I remember from my youth long ago. “Comes the Revolution”, it went, “Everybody will eat strawberries with whipped cream”. Question: What if somebody doesn’t like strawberries with whipped cream? Answer: After the Revolution, everybody will have to eat strawberries with whipped cream whether they like it or not, Or else!

    1. If you email me, as I offered above, I can send a copy of the review. I didn’t read any of the reviews before I wrote mine, and I haven’t yet read most of the published ones. The book didn’t sell very well, and I can’t even find many reviews of it online.

  8. I think you hit the nail on the head in pointing out that genetics are neither more nor less a matter of luck than the other factors that determine human behavior and outcomes. That being the case, however, the question becomes: What does this determinism imply about the morality of tolerating vs. extirpating the inequities that result from factors other than violence, deception, or other such overreaching?

    These moral implications of determinism need to be explored.

  9. Did Harden’s book consider non-random genetic variation that’s caused by assortative mating (e.g., between people with similar IQ)? This additional variation among kids from different families isn’t a lottery (though it’s deterministic in the same way everything else is), and it might greatly amplify inequity especially for traits that are easy to assess by potential mates and likely to affect each person’s desirability.

  10. Excellent, Ceiling Cat. I will add my beefs to the mix.

    First, from a paper of Harden’s on the cognitive and non-cognitive components (“soft skills”, like hard work) of educational attainment (yes, these can be parsed out; it’s a new method called “GWAS-by-Subtraction”), we know that there are genetic correlations between the non-cognitive components of educational attainment and various psychiatric traits. If we pull an equity move and remove standardized tests as criteria for admissions into universities, many will rely on their soft skills to get through. But if we environmentally increase expression of the genes in brain that boost the soft skills, since these are genetically correlated with psychiatric traits, we might also inadvertently increase mental illness. We simply don’t know that we wouldn’t. I see it as a risk.

    Second, genes are destiny in many cases, even if there exists a counterfactual world in which an intervention could be given at the right dose, at the right time, to the right person. Consider Tay Sachs. At this point, there is no cure, and those babies will die in childhood.

    Even PKU. While genetic screening exists to get kids with PKU on a special diet, and this reduces brain damage, are the IQs for most kids with PKU the same as those without PKU? I don’t think so. They are likely lower, since some damage will have occurred prior to the onset of the diet and many will not strictly adhere to the diet.

    And PKU is a Mendelian disease! Harden is talking about polygenic traits. She has over promised with the “genes aren’t destiny” schtick because in many cases, for all intents and purposes, they are.

    1. I think that PKU kids are diagnosed at birth, and can lead normal lives. But my point was that PKU used to be invariably fatal, and now it’s not. It’s monogenic, too. That gene is NOT destiny–you are guessing here about IQ and brain damage, so look it up. But also look at the fatality rate with and without dietary treatment.

  11. Yes, Jerry, I got your point, and you are correct that dietary treatment is a success story, one of the most moving in medical genetics — indeed, it’s the justification for population-based genetic screening of newborns, and not just for PKU, but for a variety of *treatable* inherited diseases. Untreated PKU used to be the most common metabolic cause of mental retardation. Those with untreated PKU typically have an IQ of <50. Thus, relative to those with PKU who are untreated, those who go on the special PKU diet are legions better off intellectually. That does NOT, however, guarantee that their lives are totally normal nor that their IQs are the same as those who don't have PKU. Even if we assume that all kids with PKU are placed on the diet within the first weeks of life, there is a relationship between their phenylalanine (Phe) levels and IQ. In addition, there may be non-cognitive abilities that are impaired even in treated PKU patients. Because IQ is typically what is measured, the possible deficits to other aspects of mental function are not well understood.

    As for a source, Jerry, here is one that points to what I am saying about the cognitive deficits that occur even with treatment:

    Quote from the abstract: "Phenylketonuria (PKU) results in profound intellectual disability in untreated individuals and more subtle cognitive deficits in individuals treated early and continuously." To cite one example, a meta-analysis of the cognitive performance of early-treated PKU patients compared to non-PKU familial controls demonstrated that the early-treated patients had lower IQs than their non-affected family members.

    Brumm VL, Grant ML. The role of intelligence in phenylketonuria: A review of research and management. Mol Genet Metab 2010; 99. doi:10.1016/j.ymgme.2009.10.015.

  12. For those who like podcasts, Kathryn Paige Harden was on recently with Julia Galef (Rationally Speaking) and Sean Carroll (Mindscape) and had a fairly contentious encounter on Sam Harris’ podcast last summer -but she held her own surprisingly well.

  13. the variation of IQ of attributable to variation in people’s genes (it’s about 40-60%).

    That’s for children, the most common subjects of IQ studies.

    For adults in Western societies it’s about 80% (A or B).

  14. This post reminds me of the book “The Giver.” My then 4th-grade daughter asked me if she could stop reading the book because she was terrified by the thought of being assigned to a job, especially, as a baby carrier.

    I think genetics plays a role in creating variations (not inequalities) that affect our success in life. The inequalities arise from the fact that ‘success’ in our life is socially defined. (I haven’t read the book and do not wish to talk over my head, so I will stop here.)

    Thank you for the review.

  15. People actively seek out environments that sing with their own natural tendencies. It’s part of their extended phenotype as Dawkins would say. The bookworm who enjoys studying and the extrovert who sneaks out to play football, they both define their own environments. So even the environmental variation has a genetic component.

    So if genetics is luck, then your environment is also luck, at least partially. Less so for children as strict parents and schools can restrict their natural habits, but as soon as you’re free, you’re going to drift towards stuff that naturally calls to you.

    What’s unfair is people whose natural tendencies are supressed because of extreme circumstances, e.g. a smart kid in a broken home. Malcolm X is a good example of that (he educated himself in prison. Imagine that! If that’s not an example of an individual seeking out his own environment, even in the most extreme circumstances, I don’t know what is).

    The system has to be better at finding the smart kids, wherever they are, and fast-track them. In short, excellence programs.

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