I’ve been trying, in this space, to rehabilitate the modern science of genetic influence on individual variation in academic outcomes to progressives. Many left-leaning people have perfectly reasonable fears about this line of inquiry, as in the past similar-sounding arguments have been used to justify eugenics, while in the present many racists make pseudoscientific arguments based on similar evidence to justify their bigotry. Like others, I am interested in showing that there are progressive ways to understand genetic behaviorism that reject racism and which support, rather than undermine, redistributive visions of social justice.
I can’t deny, though, that there are many regressive ways to make these arguments. That’s particularly true given that there’s a large overlap in the Venn diagram of IQ determinists and economic libertarians. I want to take a moment and demonstrate how conservatives misread and misuse genetic behaviorism to advance their ideological preferences for free market economics.
In this post, Ben Southwood of the conservative Adam Smith Institute uses evidence from genetic behaviorism and education research to argue that luck really doesn’t play much of a role in life outcomes. To prove this point, he cites many high-quality studies showing that random assignment (or last in/last out models) to schools of supposedly differing quality has little impact on student academic outcomes. He argues that our understanding of genetic influence on intelligence should influence our perception of how much schools can really do to help struggling students. This is, in general, a line of thinking that fits with my own. But he makes a leap into then suggesting that what we call luck (let’s say the uncontrolled vicissitudes of chance and circumstance that are beyond the control of the individual) has little or nothing to do with life outcomes. He does so because this presumably lends credence to libertarian economics, which are based on a just deserts model – the notion that the market economy basically rewards and punishes people in line with their own merit. This leap is totally unsupportable and is undermined by the very evidence he points to.
To begin with, Southwood ignores a particularly inconvenient fact for his brand of conservative determinism: the large portion of unaccounted-for variation in IQ and academic outcomes even when accounting for genetics and the shared environment (code for the portion of the environment in a child’s life controlled by parents and the family). There is famously (or notoriously) a portion of variation in measurable psychological outcomes that we can’t explain, a large portion – as much as half of the variation, maybe, depending on what study you’re looking at. And this portion seems unlikely to be explainable in systematic terms. Plomin and Daniels called this the “gloomy prospect,” writing
One gloomy prospect is that the salient environment might be unsystematic, idiosyncratic, or serendipitous events such as accidents, illnesses, or other traumas . . . . Such capricious events are likely to prove a dead end for research.
Turkheimer wrote recently:
scientific study of the nonshared environment and molecular aspects of the genome have proven much harder than anyone anticipated. But I still feel bad about harping on it, as though I am spoiling the good vibes of hardworking scientists, who are naturally optimistic about the work they are conducting. But ever since I was in graduate school, I have felt that biogenetic science has always oversold their contribution, tried to convince everyone that the next new method is going to be the one that finally turns psychology into a real natural science, drags our understanding of ourselves out of the humanistic muck. But it never actually happens.
The gloomy prospect, in other words, represents exactly the influence of what we usually refer to as luck. Southwood claims that genetics explains perhaps .90 of the variation at adult, but this represents extreme upper bound predictions for that influence. Most of the literature suggests significantly more modest heritability estimates than that. So we are left with this big uncontrolled portion, which as Turkheimer says has proven resistant to systematic understanding and which likely reflects truly idiosyncratic and individual impacts on the lives of individuals. Unfortunately for progressives who want to dramatically improve educational outcomes by changing the home environment of children, quality studies consistently find that the impact of changes to that environment is minor. Unfortunately for Southwood, the unexplained portion of academic outcomes (and subsequent economic outcomes) looks precisely like chance, or at least, that which is uncontrolled by either the individual or his or her parents. The last line of his post is thus totally unsupported by the evidence.
But there’s an even bigger issue for Southwood here: no one is in control of their own genotype. It’s bizarre when conservative-leaning people endorse genetic determinism as a justification for just-deserts economic theories. Genetic influence on human behavior stands directly in contrast to the notion that we control our own destinies. How then can Southwood advance a vision of free market economics as a system in which reward is parceled out fairly, given that the distribution of genetic material between individuals is entirely outside of their control? Which genetic code you happen to be born with is a lottery. I happen to not have gotten a scratch off ticket that allows me to have been an NFL player or a research physicist. That’s not a tragedy because I am still able to secure my basic material needs and comforts. But not everyone is so lucky, and for many the free market will result only in suffering and hopelessness.
It is immoral, and irrational, to build a society in which conditions you do not choose dictate whether you live rich and prosperous or poor and hopeless. That is true if this inequality is caused by inheriting money from your rich parents or by inheriting their genes or by being deeply influenced by the vagaries of chance. The best, most rational system in a world of uncontrolled variation in outcomes is a system that guarantees a standard of living even under the worst of luck – that is, socialism.
Correction: Southwood has taken considerable umbrage to this post, which he expressed in a dozen-tweet missive and Medium post. You should read that. I concede that I was uncharitable in how he talks about luck, and I recognize that he sees luck as impact life events. I do not agree with his claim that path dependence and luck do not contribute to life outcomes, and it’s weird that his post title alludes to Gregory Clark’s The Son Also Rises, which demonstrates that wealth benefits from inheritance can persist for far longer than traditionally thought. But that’s immaterial to the question of whether I accurately reflected Southwood’s position on luck and redistribution. So consider this an apology. I should have spoken more carefully and read more charitably and for that I’m sorry.
As for the 90% of variance figure, my wording “perhaps .90” is an accurate reading of a presentation of a range, and I don’t withdraw it. If anyone objects, I am happy to tutor them in reading, for a fee.