In reviews of his brilliant 2002 book The Blank Slate, which railed against the ‘modern denial of human nature’, Steven Pinker was accused of erecting a straw man. Nobody actually believes, scoffed the critics, that children are born with brains of soft clay, their mental makeup unaffected by genes and infinitely mouldable by their parents. Everyone acknowledges both genes and environments are important in psychological development. Don’t they? Alas, having read Not In Your Genes, the new book from celebrity psychologist Oliver James, I can confirm that such gene-phobics do exist. James is the straw man made flesh.
To open the book is to step into a parallel universe. In James’s neo-Freudian world, DNA has no effect on the mind or mental health, whereas parenting reigns supreme. His theory, largely derived from his experience as a psychotherapist, is that interactions between parents and children, especially abusive or neglectful ones, leave deep impressions, fully explaining why children become similar to their parents. The book lays the anecdotes on thick; James tries to draw lessons from the childhoods of such luminaries as Tiger Woods and Vince Cable, and includes a rather ghoulish analysis of the premature death of Peaches Geldof.
But anecdotes are not data; in fact, Not In Your Genes is a compendium of psychological myths and legends, such as the supposed effect of birth order on personality (shown in two huge 2015 studies to be small to non-existent), and the idea that 10,000 hours of practice is all it takes to become exceptional (also recently debunked).
The rest of the book is an all-out assault on genetic research. It would be a bizarre anomaly if James were correct and genetics had no effect on psychology, since about 80 per cent of human genes are expressed (have effects) in the brain. Indeed, decades of research provide ample evidence of the genetic influence on psychological traits like intelligence, personality, and mental illness. James disagrees, bending over backwards to avoid awkward conclusions (at one point risibly suggesting that ‘epigenetics’ might be why his son is psychologically similar to him; nobody has told him that, since epigenetics involves the switching on and off of genes, this would be a genetic effect). He argues that identical twins are psychologically similar not because of their identical genomes, but because parents treat them more similarly. But several studies of ‘misclassified’ twins, where parents think the pair are identical when they’re fraternal, or vice versa, contradict this assertion. Biological similarity leads to psychological similarity, regardless of parenting.
Results from studies of twins converge with those from adoptees and extended families. Nowadays, we can estimate heritability— the variation in a trait due to genes — directly from DNA using a technique called GCTA (James mentions GCTA, but his fumbled explanation reveals he hasn’t grasped how it works). GCTA heritability estimates for psychological traits appear all the time, and they fit nicely with what we’d expect from the family research.
Knowing genes influence traits is not the same as knowing which specific genes are involved. For this, we have to turn to ‘genome-wide association studies’. Because psychological traits are so complex, there are many thousands of genes that are related to them, each with a very small effect (perhaps increasing the size or efficiency of different brain structures, each by small degrees). Basic statistics tells us that, to find small effects, you need a lot of people in your study. Unfortunately, James doesn’t understand this (or much else about gene-finding studies, as evidenced by his weird and inappropriate use, throughout the book, of the term ‘Human Genome Project’ to mean ‘any molecular genetics research’). Time and time again, he argues that because geneticists have so far only identified a fraction of the genes responsible for the variation in a particular trait, the trait has no genetic basis worth mentioning. This leads him to make preposterous statements about scientists ‘universally accept[ing]’ that only a few per cent of the variation in, say, schizophrenia risk is genetic. No — they accept that the specific genes we know about so far only explain a small amount of that risk. The other specific genes — and there is strong evidence from the heritability studies that they exist — remain to be discovered.
And they are being discovered. As study sample sizes have increased, more and more of the genetic variants linked to conditions like schizophrenia have been found. There is no reason to think this trend won’t continue. In the next few months, major genome-wide studies of intelligence and personality are set to appear with exciting new findings. This tangible progress leaves James’s Lysenkoist argument looking rather forlorn. Never fear, though: James says he has talked, off the record, to geneticists who’ve told him he’s right and that the relevant genes will never be discovered. If you’ll forgive my sinking to his level, most geneticists with whom I’ve spoken off the record have told me that James’s opinions are vacuous nonsense.
Superficially, the book appears well stocked with scientific references. But just try following the citations: they frequently make precisely the opposite point to James. He often interprets honest discussion of methodological limitations as confessions that genetic research has been a let-down. The nadir is an outrageous out-of-context quotation from geneticist Robert Plomin, who recently stated: ‘I’ve been looking for these genes for 15 years and I don’t have any.’ Plomin was arguing— given his knowledge of the results from twins and GCTA — that the specific genes would be found with larger samples and better technology. In James’s hands, the quote is transformed into a cowed admission of failure.
Few books risk such damage to the public understanding of science as those by Oliver James. Inexplicably popular despite their scientific illiteracy and mediocre writing, they are promoted widely by James’s regular, shriekingly aggressive media appearances. A glance at the studies shows the absurdity of the extreme blank-slate position advanced in Not In Your Genes: environments clearly matter, but so does DNA, and the perversity of denying this becomes ever more acute with each new genetic discovery. Truly understanding human psychology and helping those with psychiatric illnesses requires us to have a realistic view of the causes of differences between people. That realistic view is Not In This Book.
Stuart Ritchie is a postdoctoral research fellow in the psychology department at the University of Edinburgh. Follow him on Twitter: @StuartJRitchie