Genetic Determinism Redux Nathaniel Comfort Questions a Psychologist’S Troubling Claims About Genes and Behaviour

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What should babies be screened for, and who should share in the data?

SOCIETY Genetic determinism redux Nathaniel Comfort questions a psychologist’s troubling claims about genes and behaviour.

t’s never a good time for another bout worse eugenics. The in recent years has lured social scientists of genetic determinism, but it’s hard flowering of medical to the genome, with the promise of genetic to imagine a worse one than this. genetics in the 1950s explanations for complex traits, such as ISocial inequality gapes, exacerbated by led to the notorious, voting behaviour or investment strategies. climate change, driving hostility towards now-debunked idea As Plomin notes, it was something they had immigrants and flares of militant racism. At that men with an extra been trying to do for a long time. such a juncture, yet another expression of the Y chromosome (XYY Plomin’s predecessors tried to get mono- discredited, simplistic idea that genes alone genotype) were prone genic risk scores. For example, Henry control human nature seems particularly to violence. Heredi- Goddard, an educational psychologist who insidious. tarian books such as Blueprint: How from 1906 to 1918 directed the New Jersey And yet, here we are again with Blueprint, Charles Murray and DNA Makes Us Training School for Feeble-Minded Girls by educational psychologist Robert Plomin. Richard Herrnstein’s Who We Are and Boys in Vineland, claimed he had found Although Plomin frequently uses more civil, The Bell Curve (1994) ROBERT PLOMIN the gene for low intelligence. With Charles progressive language than did his predeces- and Nicholas Wade’s Allen Lane (2018) Davenport, a prominent US eugenicist, sors, the book’s message is vintage genetic 2014 A Troublesome whispering in his ear, Goddard suggested determinism: “DNA isn’t all that matters Inheritance (see N. Comfort Nature 513, 306– that learning disabilities resulted from a but it matters more than everything else put 307; 2014) exploited their respective scientific single Mendelian recessive gene. Scanning together”. “Nice parents have nice children and cultural moments, leveraging the cultural the swathes of pedigrees he had collected because they are all nice genetically.” And authority of science to advance a discredited, (progressive-era ‘big data’; see Nature 558, it’s not just any nucleic acid that matters; it is undemocratic agenda. Although Blueprint is 28–29; 2018), he identified what seemed to be human chromosomal DNA. Sorry, micro- cut from different ideological cloth, the con- a unit character: an apparent recessive “gene biologists, epigeneticists, RNA experts, sequences could be just as grave. for” learning disability. When he factored in developmental biologists: you’re not part of The scientific advance this time is the behaviours thought to result from that con- Plomin’s picture. genome-wide association study (GWAS). dition — such as criminality and promiscu- Crude hereditarianism often re-emerges Invented in 1996, GWAS has gained mas- ity — the alleged association went sky-high. after major advances in biological knowledge: sively in predictive power with the advent Goddard’s pedigrees bloomed with antisocial Darwinism begat eugenics; Mendelism begat of ‘polygenic scores’, a statistical tool that traits, which he believed were passed down

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Free, healthy school meals have been shown to improve educational attainment

the generations as a Mendelian recessive environmental effects, such as breastfeeding and to talk instead of graded “dimensions”— gene. He never seems to have questioned and TV-watching on school achievement. If personality traits, such as introversion or whether a single gene for such a complex trait all you have is a polygenic score, everything agreeableness. “All children have special made sense biologically. It doesn’t. looks like a gene. Blueprint is uncritical DNA needs,” he once told the newspaper The No one is so foolish as to believe in a single boosterism, and Plomin “unabashedly a Guardian. In a book so filled with retrograde gene for learning disability any more. As has cheerleader” by his own admission. ideas about genes, I was pleasantly surprised been well established, the genetic contribu- Polygenic scores do suggest some things to to find this strong, welcome biological sup- tion to complex traits is spread over many cheer about. We should applaud the broad- port for the idea of neurodiversity. genes, each contributing a minuscule sliver based shift across biomedicine from mono- In fundamental ways, however, Plomin’s of the variability for the trait. Polygenic risk genic to polygenic causation. This approach argument is just old hereditarian wine pipet- scores sum and weight these many tiny analyses behaviour in a much more complex, ted into thousands of tiny polygenic bottles. effects, creating what some researchers have surgical way than the crude stabs of Goddard’s In 1969, educational psychologist Arthur called a “monogenic equivalent”— a “gene ilk. The method is Jensen dropped a pseudo-statistical bomb- for” by proxy. finding wide appli- “Plomin’s shell in the Harvard Educational Review. He A polygenic score is a correlation coeffi- cation, from preci- argument is just argued that genetics was responsible for the cient. A GWAS identifies single nucleotide sion medicine to old hereditarian notional IQ gap between African Americans polymorphisms (SNPs) in the DNA that field biology. For wine pipetted and white people (not bias baked into the test correlate with the trait of interest. The SNPs example, polygenic into thousands or environmental effects) and that remedial are markers only. Although they might, in scores have been of tiny polygenic education was pointless. Jensen’s arguments some cases, suggest genomic neighbourhoods shown to improve bottles.” and much of his ‘data’ were old, part of a dark in which to search for genes that directly risk predictions for tradition of hereditarian social science that affect the trait, the polygenic score itself is prostate, ovarian and breast cancers. They would subsequently emerge in books such in no sense causal. Plomin understands this can point to traits that might have been influ- as The Bell Curve. Blueprint uses language, and says so repeatedly in the book — yet enced by local adaptation, and gauge the pace imagery, rhetoric, conclusions and numbers contradicts himself several times by arguing of evolutionary change. that will be familiar to readers who have, that the scores are, in fact, causal. Plomin adopts the language of person- like me, slogged through all these works. A Plomin deploys a standard feint in heredi- alized medicine to call for DNA-driven sobering theme of most, Blueprint included, tarian psychology, insisting on the trivial advances in education policy — “person- is their aspiration of shaping social policy. so‑called first law of behavioural genetics: that alized learning”. He argues that we should Like much of that literature, Blueprint no psychological trait is entirely unaffected think of personality traits as we do autism plays fast and loose with the concept of herit- by genetics. But he insists that “genetics is the or attention-deficit hyperactivity disorder: as ability. Sometimes Plomin treats it (correctly) main systematic force in life”, often mediat- existing on spectra. He urges psychologists as a variable property of a population in a ing both gene–environment effects and even to move away from the language of disorders given environment. As population geneticist

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Richard Lewontin pointed out in a scathing critique of Jensen’s approach in 1970, in times of plenty, height is highly heritable; in a fam- Books in brief ine, much less so (R. C. Lewontin Bull. Atom. Sci. 26, 2–8; 1970). But elsewhere, Plomin, Primate Change: How the World We Made Is Remaking Us like Jensen, treats heritability wrongly as a Vybarr Cregan-Reid Octopus (2018) property inherent in a trait. Nature and nurture commingle to fascinating effect in this study Blueprint does depart from much prior of how the environment humans have so thoroughly altered is hereditarian social science in not explicitly altering us physiologically. Humanities scholar Vybarr Cregan-Reid mentioning race — the hot-button issue ventures from the African forest apes of 20 million years ago to the of many earlier works. It instead looks at rise of Homo sapiens and the impacts of successive revolutions — class. Plomin uses a data set of mostly white agricultural, industrial, urban and digital — on our anatomy. Our British twins, most of whom attended Eng- grossly sedentary, technologically dominated, polluted present, he lish grammar schools. Yet, given Plomin’s argues, constitutes a collective assault on bodies unevolved to cope, extensive experience and his footnotes, the leading to ‘mismatch’ conditions such as myopia and obesity. absence of any explicit mention of race (to disavow it, say, or to allude to intersectional- ity) is conspicuous. Sex on the Kitchen Table The most troubling thing about Blueprint Norman C. Ellstrand University of Chicago Press (2018) is its Panglossian DNA determinism. Plomin The sex life of an avocado might seem anything but lurid. Geneticist foresees private, direct-to-consumer compa- Norman Ellstrand, however, reveals it as a riot of romantic yearning nies selling sets of polygenic scores to aca- and ‘sex switching’. In his foray into the nexus of food, science and demic programmes or workplaces. Yet, as plant reproduction, we enter that alternative universe in which this “incorrigible optimist” assures us, “suc- olives and quinces are really vehicles for seeds, the tomato (the ‘love cess and failure — and credit and blame — in apple’ of yore) is self-fertile and cultivated bananas are female- overcoming problems should be calibrated sterile. You’ll become reacquainted with the pistil, and wonder at the relative to genetic strengths and weaknesses”, sugar beet’s rise “from a cascade of geopolitical incidents”. Nutrition not environmental ones. All is for the best in might never seem the same again. this best of brave new worlds. Plomin likes to say that various com- ponents of nurture “matter, but they don’t Heart: A History make a difference”. But the benefits of good Sandeep Jauhar Oneworld (2018) teaching, of school lunches and breakfasts, of Cardiologist Sandeep Jauhar’s exploration of that marvellous having textbooks and air-conditioning and muscle, the heart, meshes cutting-edge science, memoir and history. heating and plumbing have been established He pictures a cadaver’s heart as “a squat volcano tipped on its side”. irrefutably. And they actually are causal: He extols physician William Harvey’s great 1628 treatise On the we know why stable blood sugar improves Motion of the Heart and Blood in Animals. He records the troubled mental concentration. Yet Plomin dismisses dawn of open-heart surgery, pioneered by experimentalists such as such effects as “unsystematic and unstable, C. Walton Lillehei in the 1950s. And he recounts with raw immediacy so there’s not much we can do about them”. his mother’s death from cardiac arrest. A moving narrative echoing Ultimately, if unintentionally, Blueprint to the beat of “this organ, prime mover and citadel”. is a road map for regressive social policy. Nothing here seems overtly hostile, to school children or anyone else. But Plomin’s argu- The Cryotron Files ment provides live ammunition for those Iain Dey and Douglas Buck Icon (2018) who would abandon proven methods of This extraordinary chapter in the annals of cold-war science is improving academic achievement among both thrilleresque and tragic. At its centre is Dudley Buck, a gifted socio-economically deprived children. His electrical engineer and US government agent whose prototype utopia is a forensic world, dictated by poly- microchip, the Cryotron, was key to a covert scheme to create the genic algorithms and the whims of those first supercomputers. As journalist Iain Dey and Buck’s son Douglas who know how to use them. People would be reveal, Buck and his colleague Louis Ridenour, a physicist, died defined at birth by their DNA. Expectations suddenly in 1959, after a visit from high-level Soviet researchers. Any would be set, and opportunities, resources discussion of Soviet contact-poison hits is speculative; what is not is and experiences would be doled out — and Buck’s substantial contribution to modern computer science. withheld — a priori, before anyone has had a chance to show their mettle. To paraphrase Lewontin in his 1970 cri- Poached tique of Jensen’s argument, Plomin has made Rachel Love Nuwer Dacapo (2018) it pretty clear what kind of world he wants. From the hacked corpses of bull elephants in Botswana to fast- I oppose him. ■ declining pangolin populations, wildlife trafficking is an ongoing threat to conservation gains. Rachel Nuwer, a conservation biologist Nathaniel Comfort is professor of the history turned science journalist, traces at first hand the front lines across of medicine at Johns Hopkins University in the globe in her hard-hitting, wince-inducing report. Examining the Baltimore, Maryland. His most recent book forces driving demand, the trade itself and countermeasures, she is The Science of Human Perfection (2012). takes us from Africa’s killing fields to the corridors of regulatory He is working on a biography of DNA. behemoths, and finds gleams of hope in Chad’s National Elephant e-mail: [email protected] Action Plan and pangolin rescue efforts in Vietnam. Barbara Kiser