← Back to Library

Heritability as stalking horse for mutability

Freddie deBoer delivers a startling pivot in the debate over intelligence and education: the obsession with genetic heritability is often just a distraction from the harder, more uncomfortable truth about the limits of educational reform. While the public fixates on whether genes or environment drive success, deBoer argues that the real story is the stubborn, unyielding stability of individual academic performance over a lifetime, regardless of policy interventions.

The Silent Crisis of Prematurity

DeBoer begins by grounding the abstract debate in a concrete, yet ignored, medical reality. He highlights that severe prematurity carries academic disadvantages comparable to fetal alcohol syndrome, a fact that should be common knowledge but remains absent from public discourse. "The negative impact of prematurity is very large," deBoer writes, noting that the effect sizes are significant enough to rival those of behaviors society aggressively polices, like alcohol consumption during pregnancy. Yet, while pregnant women are "bludgeoned" with warnings about deli meats and hot baths, the lasting cognitive hurdles of preterm birth go unmentioned.

Heritability as stalking horse for mutability

This silence is telling. It suggests a collective unwillingness to acknowledge biological limits that cannot be fixed by better parenting or policy. The author draws a sharp parallel to the history of Genome-wide association studies, where the initial hope of pinpointing single genes for complex traits gave way to the realization of immense polygenicity. Just as the science of genetics has grown more complex, the public conversation has remained stuck in a binary of nature versus nurture, missing the nuance that biological factors can impose hard ceilings.

The Myth of the Blank Slate

The core of deBoer's argument targets the educational establishment's refusal to accept that students have inherent, unchangeable limits. He critiques the "blank slate" ideology that dominates schools and universities, where the assumption is that every child can be pushed to the top of the academic hierarchy. "In the education policy world... every child is capable of any academic outcome," deBoer observes. This belief is so entrenched that suggesting otherwise gets a teacher "shouted out of the room."

He points to the bipartisan legacy of major legislation like the No Child Left Behind Act as proof of this dogma. The very name of the act reflects a political commitment to the idea that no student is left behind because of their innate capacity. DeBoer argues this is a dangerous fantasy. "The two most important American educational bills in the 21st century... express exactly what the politicians who drafted them believed was possible," he notes. But the evidence suggests otherwise: students tend to gravitate to a specific level of performance early in life and stay there, regardless of the school type or pedagogical intervention.

Critics might argue that deBoer underestimates the potential of early childhood interventions or the impact of systemic inequities that mimic innate limits. However, his point is not that schools are useless, but that they cannot overcome the statistical reality of individual variation in cognitive potential.

In most public debates about genetic influence on intelligence or academic aptitude, discussion of heritability is really about mutability or plasticity - that is, about how much we think a trait can be changed.

Heritability as a Trojan Horse

DeBoer reframes the entire debate: the fight over "missing heritability" is not really about genetics; it is a proxy war over how much we are willing to accept that some people will always struggle. He argues that the "blank slate" perspective is held not because it is scientifically accurate, but because admitting limits feels morally unacceptable. "The blank slate perspective... is that these traits are not at all heritable, because if they are heritable there are limits to human possibility and to the social potential of schooling, and that's uncomfortable," he writes.

He identifies a tragic middle ground that both sides ignore. The "human biodiversity" crowd wants heritability to be high to justify permanent inequality, while progressives want it to be zero to justify unlimited potential. Both miss the reality deBoer champions: that group gaps may be environmental, but individual differences are real and often biological. "My concern... is fundamentally for those who suffer because of their lack of natural talent," deBoer asserts. He argues that ignoring these intrinsic differences leads to a system that blames children for failing to meet impossible standards.

The author's framing is effective because it shifts the moral burden. Instead of asking "Why can't this child succeed?" the question becomes "How do we build a society that values children who cannot succeed in the current meritocratic model?" This is a radical departure from the current discourse, which assumes that with enough effort, anyone can be a valedictorian.

Bottom Line

DeBoer's strongest move is exposing the emotional and political roots of the "blank slate" ideology, revealing it as a refusal to confront the reality of human variation. His biggest vulnerability lies in the potential for his arguments to be co-opted by those who wish to abandon struggling students entirely, rather than reimagining the system to support them. The reader must watch for how this nuanced view of "intrinsic limits" is received by a political landscape that demands total equality of outcome. The most compelling takeaway is that the debate is not about genes, but about whether we are brave enough to accept that not every child can be a high achiever, and that we must stop blaming them for it.

Deep Dives

Explore these related deep dives:

  • Genome-wide association study

    Central to the article's discussion of 'missing heritability' - GWAS is the method that finds far less genetic influence than twin studies predict, which is the core scientific debate being examined

  • No Child Left Behind Act

    Explicitly mentioned as one of 'the two most important American educational bills in the 21st century' - the article argues this legislation embodies blank slate assumptions about student potential

  • Fetal alcohol spectrum disorder

    The article compares preterm birth academic effects to fetal alcohol syndrome effects as a benchmark for severity - understanding this condition provides crucial context for the magnitude of harm being discussed

Sources

Heritability as stalking horse for mutability

by Freddie deBoer · · Read full article

CORRECTION: I goofed! This post attributes a post written by Sasha Gusev to Eric Hoel. Hoel shared the piece on Substack Notes and Gusev’s name does not appear on the piece, and I was confused. (Also I haven't slept more than three or four hours in a night since late March.) It's my bad and I regret the error: apologies to both. As Hoel has explicitly endorsed the piece, all of the arguments here stand.

For about a decade now I’ve followed the research about the negative effects of preterm birth on later academic achievement. I’m interested in part because I’ve wondered why, exactly, there doesn’t appear to be much public knowledge about the topic. It would appear to be the kind of phenomenon that prospective parents obsess over, and yet most people seem to have no idea that the association exists.

The effect has been replicated in dozens of papers, which have been combined in several high-quality meta-analyses, and in the context of educational research where effect sizes tend to be quite small the negative impact of prematurity is very large. Most of the research specifically concerns severe prematurity, so this next part is a little less certain, but the effects do indeed scale with the severity of prematurity at the extremes of preterm birth and the best evidence is that it has some impact on babies who are much less premature but still premature. Intuitively, that is to say, you’d expect the effect to scale even with prematurity that does not reach the medical threshold of severity. (Of course, the “correct” amount of gestational time varies naturally and babies born a little early would have small effects that could be easily canceled out by other factors that influence cognition.) In any event, we know that severely premature babies tend (tend!) to grow into children that face serious academic hurdles, and the degree of this impairment is as large or larger than those thought to be the result of many behaviors we discourage in pregnant women.

What kind of effect sizes are we seeing here? With the inevitable caveat that there’s lots of individual variability (plenty of premature babies go on to be high-achieving children), and bearing in mind that different studies look at different DVs, the most prominent meta-analyses report negative academic effects of severe prematurity that are comparable to those of children born with fetal alcohol syndrome. ...