My Review of Kathryn Paige Harden's "The Genetic Lottery "

Every few years, the scant evidence for genetic determinism will be promoted and sold in book form. In 2018, it was Robert Plomin’s “Blueprint.”  The latest comes from psychologist and behavior geneticist, Kathryn Paige Harden, with her new book: “The Genetic Lottery - Why DNA Matters for Social Equality.” From the title alone, one can see that she will be selling a version of genetic determinism with a heart. To her credit, in contrast to Plomin, Harden addresses the ramifications of behavioral genetics’ historical association with eugenics in some detail, but her book is otherwise similar in substance to Blueprint (despite her own negative review of Blueprint). Both books spin polygenic scores as a savior for the failing field of behavioral genetics, with the dubious suggestion that these results are “causal.”  

In Plomin’s case, his fanaticism for polygenic scores could be written off as wishful thinking for a man at the end of his career, touting a perceived future of ever improving polygenic prediction. Harden, on the other hand, has had a few years to see the hype dwindle, with study after study noting the limitations of such scores. 

Harden’s primary focus is what is referred to as “educational attainment,” basically a simple measurement of how far someone goes in school, viewing it as a trait with some genetic basis. In truth, this “trait” is a bit of subterfuge, serving as a proxy for intelligence, while avoiding some of the controversy surrounding genetic studies of IQ (and their association with books like Charles Murray’s, “The Bell Curve”). 

Harden's writing style at times involves condescending oversimplification through analogy: “If a gene is a recipe, then your genome -  all the DNA contained in all of your cells - is a large collection of recipes, an enormous cookbook.” This quaint presentation of the subject suggests that she is targeting a lay audience, but I question whether those not already familiar with this kind of research would find this book engaging and these analogies do not appear to clarify the subject in a more comprehensible manner.

Books of this nature generally have the same two issues to tackle and Harden’s is no exception. The first is to sell the scientific evidence related to claims of a genetic basis for educational attainment and other behavioral traits. The second relates to the ethical and practical implications of this research. I will address her treatment of both issues here, beginning with the latter.

As Harden notes: “When people hear ‘genes’ or ‘intelligence’ - particularly in the United States - they cannot help but hear ‘race.’” I’m not sure this is what comes to mind for me, but it’s certainly true for many of those touting these types of genetic studies, often using them as fodder for eugenic, classist and racist ideas, thinly disguised as science.  Harden addresses the historical relationship between behavioral genetics and eugenics head on, but this leaves her trying to push largely hypothetical “benefits” of genetic studies, with a reframing of the ideas as egalitarian.

“What I am aiming to do in this book is re-envision the relationship between genetic science and equality… Can we imagine a new synthesis? And can this new synthesis broaden our understanding of what equality looks like and how to achieve it?”

I think that this falls flat and demonstrates a naive understanding of just what she is up against. Rather than admit that these studies feed fascistic and racist ideas, she attempts to “both-sides” the issues, focusing on leftists, for whom she appears to have some disdain, fancying herself as some kind of sensible centrist, by contrast. Case in point is her interpretation of a study related to bias towards genetic determinists:

“... a scientist who reported genetic influence on intelligence was also perceived as less objective, more motivated to prove a particular hypothesis, and more likely to hold non-egalitarian beliefs that predated their scientific research career…people who described themselves as politically liberal were particularly likely to doubt the scientist’s objectivity when she reported genetic influences on intelligence.”

Her point here is to paint the left as hopelessly biased on this subject, but despite Harden’s dubious effort to paint herself as a leftist, many individuals touting genetic determinist views also harbor racist and classist views that are hardly egalitarian. There are obvious reasons for this and it doesn’t take a leftist to distrust their motives, nor should one expect leftists to embrace a sugar-coated version of genetic determinism.

As Harden acknowledges, the field of behavioral genetics was largely founded on the backs of racist eugenicists such as Francis Galton and Karl Pearson. We still see this today, perhaps in a more attenuated form, both from scientific poseurs like Charles Murray, as well as renowned scientists, such as James Watson. Imagine expecting them to “re-envision” their view of the world. This demonstrates a real inability to read the room and, if there was any doubt about that, we already have race-oriented “scientists” embracing aspects of Harden’s book.

Nonetheless, what matters in the end is the validity of the science and the book is written under the presumption that the science is settled. This couldn’t be further from the truth. Books of this nature can’t rely solely on actual scientific evidence, because there isn’t much there. Their acceptance relies on decades of hyperbole, ingraining the psyche of society, at large. Even those having little familiarity with the subject have been exposed to enough headlines in news media suggesting genes have been “found” for intelligence, schizophrenia, personality traits or your favorite flavor of ice cream. This is bolstered by futuristic books and movies, presenting a  mythology, dystopic or otherwise, of genetic deification.

The actual science is far less impressive, and for those not familiar, it essentially relies on establishing genetic “correlations,” without defining what or how these genes might influence a particular trait. The principle behind the studies is not much different than what commercial genealogy sites like Ancestry.com do, but instead of establishing ethnicity or ancestry, they correlate the genetic variants that are more common in one group than another for a particular behavioral trait, or just about anything that can be designated on a questionnaire. Then they score the total number of these correlated variants a person has for a “polygenic score,” the idea being that a higher score makes it more likely you will have the trait. This is based on the hypothesis that traits are “polygenic,” consisting of hundreds or thousands of genetic variants. It is a probabilistic assessment, with no definitive set of genetic variants that would confer a trait or explanation of how any of these variants would contribute to the trait, nor explain why many with high scores do not have the trait and many with low scores do.

In truth, applying a polygenic score for a trait isn’t a whole lot different than commercial genealogy sites assessing whether someone has genetic variation that is more common for, say, Italian or Korean people. The difference is that Ancestry.com is not absurdly claiming that these genetic variations are causing Italians to like pizza or Koreans to use chopsticks. That, however, is essentially what behavioral geneticists are trying to claim, but instead of pizza or chopsticks, Harden is focused largely on so-called “educational attainment.” 

Much of the genetic variation we find in people is due to genetic drift, where populations in historically isolated parts of the world randomly acquire different genetic variants over generations, that will be more common among people in a particular region. These genetic variations generally have little or no known functional difference, but can serve as genealogy identifiers. Geography is probably the most important aspect in looking at ancestry, although individuals of different ethnicity, living in the same region might also acquire common, distinguishing variants due to marrying within their own group (a form of assortative mating).  In either case, these phenomena create what is called “population stratification” and allow you to distinguish populations via their genetics.

It’s not difficult to see how a trait like educational attainment would be subject to population stratification. People of one social class will marry others in the same class and highly educated individuals will tend to marry others in that social class and push their children in that direction for successive generations. Harden is arguing that these people have, at least in part, won the genetic lottery and that the genes they have in common confer some abilities that allow them to achieve higher education over those who are more, say, blue collar. To assume this up front, in my view, is an aristocratic way of thinking.

The problem here is that you add nothing to the argument by pedantically looking at the genetic variants that are found in different social classes. Of course you will find genetic variants that are more or less frequent due to long-standing population stratification, but are you really doing anything more than correlating Italians to pizza and Koreans to chopsticks? I contend that you are not and Harden and others in the field, all highly educated, and mostly from privileged backgrounds, should be wary of doing such self-affirming research on educational attainment.  Believing that people within these privileged classes have actual genetic variants that allow them to be “... smart and curious and hard-working,” in some way that confers educational attainment is blind to both common sense and the obvious realities of the society we (and the UK, where many of these studies arise) live in.  Although Harden does acknowledge  some of the factors leading to this kind of confounding in genetic studies, she tries to make the case that these factors can be weeded out, leaving us with only the good stuff. 

There are a number of problems with this claim. The first is that the claimed high heritability of a trait like “educational attainment,” like other behavioral traits, was divined by twin studies, which Harden defends, but these studies are simply not confirmed by actual genetic studies, which find miniscule heritability by comparison. This leaves behavioral geneticists to flailingly suggest that there is “missing heritability” still to be found. Harden attempts to explain this as being due to “...particularly rare genetic variants which might have especially large effects.” In other words, the genetic variants that aren’t common enough to be picked up in a GWAS genetic study just happen to have all the missing heritability. There is no evidence to support this and, frankly, it smacks of desperation.  

Thus, we have the circular argument that keeps the field of behavioral genetics alive: The heritability of a trait seen in twin studies proves there is a genetic basis for that trait, and the fact that we are not able to confirm twin studies via genetic studies shows only that we haven’t found the genes we expected yet, but we know must exist because of twin studies. Such circular assumptions are then presented as established science. For example, Harden claims as fact that behavioral traits are “polygenic”:

“Schizophrenia and autism and depression and obesity and educational attainment are not associated with one gene. They are not associated with even a dozen different SNPs. They are polygenic - associated with thousands upon thousands of SNP’s [genetic variants] scattered all throughout a person’s genome.”

These contradictory assumptions leave us with a “polygenic” model with thousands of genetic variants adding up to a tiny bit of heritability, and unidentified “rare variants,” to be found at a later date, accounting for the remaining huge chunks of missing heritability. This is simply wishful thinking. 

Nonetheless, Harden embraces the idea that these genetic studies will someday close the gap on this missing heritability, touting a recent study for educational attainment in which she claims,  “You can account for 13% of the variance.” Although this is not anywhere near what one would expect from twin studies, on the surface it is significantly better than the usual 2 to 3% that such studies generally yield. It is a bit of sleight hand, however, for Harden to tout this figure, when she also touts within family studies (comparing the genetics of siblings and their parents and then assessing their educational attainment polygenic score), as a way to strip down to the actual causal genes, and such a study was conducted and brought this figure back down to 2 or 3%. Such decreases are merely a flesh wound for Harden, though, who notes that,  “... the heritability of educational attainment is still not zero.”  

However, that’s not really certain, for a couple of reasons. The first is that when you are at such a low percentage, you could be merely talking about statistical aberrations. As one recent study describing such “measurement errors” notes: “We find that sibling models, in general, fail to uncover direct genetic effects… Our findings suggest that interpreting results from sibling analysis aimed at uncovering direct genetic effects should be treated with caution.” 

Secondly, we have no idea what most of the genes in question actually do, so even if you argue that these genetic variants are causal, you haven’t ruled out physical causation to explain this small percentage. Traits that Harden herself notes such as “pretty, tall, skinny, light-colored,” which would hardly convey a meritorious advantage towards educational attainment might be all that we are really seeing. Perhaps that is the true “genetic lottery.” Thus, arguably, when talking about miniscule results like this, you might, indeed, truly be at zero genetic influence, leaving her entire book promoting a faulty premise.

Moreover, there is another significant problem with these genetic studies and the derived polygenic scores: They are largely useless outside of the ancestry group being studied,  which is usually those of white European ancestry. Harden addresses this to an extent:

“I anticipate that scientists will have developed a polygenic score that is as strongly related statistically to academic achievement in Black students as it is in White students.”

  There are a number of difficulties with this statement. The first is that it is probably not going to be the case. The polygenic score for educational “achievement” relies on population stratification that has probably not had as much time to develop in the West for those of African ancestry. Moreover, there is an assumption underlying that, which is that what would constitute genetics of educational attainment would involve entirely different genes for Black students than those used to assess White students. This should reinforce the fact that these scores are based largely on population stratification, and should make it clear that the genetic variants have no real function. There is simply no reason to believe that a collection of genetic variants would be entirely different from one ancestral group to another and still confer the same behavioral trait. Despite her attempt at logical extension, you  can’t just make this assumption because you believe it to be true for a person’s height or milk production in cows (which have their own problems).

If this isn’t obvious for a singularly numeric trait like educational attainment, consider a trait that is not as easily quantifiable, like schizophrenia. Like educational attainment, a polygenic score for schizophrenia based on a white European population, would not be useful for an African American population. So again you would be forced to surmise that Black and White people who get schizophrenia have an entirely different collection of genetic variants that "cause" schizophrenia. Yet, schizophrenia has about the same prevalence in African Americans and those of White European descent, and it presents in the same manner. This is not consistent with separate genetic mechanisms and should lead to the conclusion that genetics are not the primary mechanism behind it. The same could be said for depression, bipolar disorder, personality disorders or just about any behavioral trait. No one is claiming a significant difference in the presentation of these traits or the general prevalence in different ancestral populations, which one would expect from separate polygenic influences.

Another obvious concern with such separate but equal polygenic mechanisms, is that it will fuel the very racists Harden denounces. Harden is careful to make the distinction between ancestry and race and, while the distinction is important, for those engaging in “race science,” referring to individuals as African ancestry is hardly going to dissuade them from extending this to racist conclusions.

It’s also worth pointing out that, like most books related to this subject, Harden presents, at best, a sophomoric understanding of human psychology. There is no theory or dynamic formulation to be found. There is no debate to be had, other than statistical sophistry, to argue that schizophrenia, depression, educational achievement, or other traits are “partly genetic.” With that called into question, you are left with little else, but “bluster and bluff and empty show.” It’s shocking that the bulk of resources for psychology research are being poured into this pedantic shell game. It has contributed nothing to the field after decades of this research, has historically caused a lot of harm, and probably will continue to do so. Harden cannot hope to  “re-envision” the field, because it has no validity and too many of those who embrace it have dubious motives. Her book, like those preceding it, props up a field that is apparently too big to fail.  

My review of Kevin Mitchell’s, “Innate” available here: http://unwashedgenes.blogspot.com/2023/05/review-of-innate-by-kevin-mitchell.html