Recently, Freddie DeBoer published a book titled "Cult of the Smart" that outlines a hereditarian (somebody who believes in direct and isolated genetic causes determine complex behaviors) left-wing perspective on education. The central thesis of the book is that individuals come endowed with an "intrinsic ability" to excel in school. Some students, no matter how much effort is placed on improving their abilities, will fail, and it's therefore cruel to link ones economic prospects and social welfare to educational outcomes. As somebody on the left I am in broad agreement with decoupling academic from economic prospects, but when talking about the genetic influences over behavior Freddie writes in line with Plomin's recent flawed book "Blueprint" (see review here). One gets the feel that the author took a dive into popular accounts and blogs written by behavioral geneticists, but remained largely (willfully?) unaware that this whole field has been marred in controversy throughout its short existence. Large parts of the book opine that while we are told that our destiny can be the stars, in reality its deeply engrained in our genes. What's not discussed is the near failure of molecular methods to uncover this underlying genetic architecture for human behavior. As stated eloquently by Aaron Panofsky in his book "Misbehaving Science": "Molecular genetics has been a major disappointment, if not an outright failure, in behavior genetics. Scientists have made many bold claims about genes for behavioral traits or mental disorders only to later retract them or to have them not replicated by other scientists. Further, the findings that have been confirmed, or not yet falsified, have been few, far be tween, and small in magnitude." As somebody who studies behavioral development it struck me how easily the author just accepted heritability estimates were an accurate measure of genetic causation without giving the scholarship on this topic its due diligence. This is surprising because the application of heritability estimates on humans has had a contentious history, and there is a large body of scholarly work on both sides to draw from. At its core heritability estimates are a population level descriptive statistic that calculates the recurrence of specific traits in families. They don’t measure genetic causes. Like any statistical measure it also comes with specific assumptions. In the case of heritability estimates, its core assumption is the existence of unmeasured direct and isolated genetic and environmental causes that exist at the individual level, and can be uncovered via partitioning phenotypic variation at the population level. While such partitioning has been a convenient way to bypass developmental processes, research on development has shown such partitioning to be a limited (and in most contexts, such as humans) invalid assumption (see https://doi.org/10.1080/10407410902877157 & https://doi.org/10.1111/j.1467-7687.2007.00556.x). This means that researchers who use heritability estimates often have much more nuanced perspective now than they did 10 years ago. Furthermore, the existence of "missing heritability" where heritability estimates from genomic techniques (such as GWAS and polygenic risk scores) are often smaller by orders of magnitude than heritability estimates from twin studies, has further questioned the ability to heritability studies to uncover genetic causes. While such molecular techniques are mentioned in the book their lack of concordance with more traditional behavioral genetics is glossed over completely. Freddie DeBoer also seems to take at face value a core assumption from behavior genetics the dose not hold up to scrutiny; the equal environments assumption (EEA). The EEA states that for all intensive purposes people sharing the same household have the same "environment". Many of the studies he cites have strong methodological problems. For example, in the Minnesota Twin Family Study monozygotic twins reared separately were often raised by relatives on the same street, interacted constantly, and went to the same school. These twins were however considered to have an "unshared environment" simply because they were raised in a different household. Controlled lab studies have also questioned the feasibility of the EEA. In 1999 a group of mouse geneticists across different labs tried to uncover the underlying genetic structure of behavior by standardizing the environment of inbred laboratory mouse strains across labs to a degree never achieved before. The result was large phenotypic differences both within and across labs, highlighting the stochasticity of developmental processes and largely putting the EEA to bed for everybody outside of a few behavioral geneticists (https://science.sciencemag.org/content/284/5420/1670). Further research has shown that even clonal mice housed in identical environments will develop distinct individualities based on slight social and stochastic differences in direct experiences (https://science.sciencemag.org/content/340/6133/756). The EEA does not hold. Freddie's book largely ignored the evidence from developmental psychobiologists, and throughout the book fails to address the near-consensus that the unmeasured developmental confounds outside the genome contribute to high heritability estimates in humans. He unquestioningly accepts the supposed fact that educational outcome are 0.5 to 0.8 heritable (which he interprets as upwards of 80% of educational outcome are determined via "genes") despite the fact that in controlled laboratory conditions, the only consistent heritability estimates for much simpler behaviors in animals are lower. The fact that even "purely genetic" conditions such as phenylketonuria (caused by a single nucleotide change in a single gene) can be cured with a 100% environment intervention (removing phenylalanine from the diet complex) should give one pause when discussing outcomes such as "education" and "intelligence". But not here. All behaviors investigated in detail have show that gene-organism-environment interactions form an irreducible network of ontogenetic resources necessary to cause the expression of any behavior at any point in time. There is, simply put, no room anymore for considering direct, isolated, & magnitude specific genetic or environmental causes within the interactive and relational reality of biological development. I ask Freddie DeBoer to read "The Ontogeny of Information" by Susan Oyama, "Synthesizing Nature-nurture" by Gilbert Gottlieb, "Basic Instinct" by Marc Blumberg , "The Dynamics of Behavioral Development" by Zing-Yang Kuo and "Design for a Life" by Patrick Bateson to balance out the one sided treatment drawn from the niche and controversy laden field of behavioral genetics. The book draws from a very limited range of behavioral genetic researchers, some of which who's work on the genetics of education have seen flattering endorsements from Charles Murray, author of the notorious and racist "Bell Curve". Many arguments in the book are supported by researchers, bloggers, and think tanks interested in "public choice" and market fundamentalist school policies that directly contrast with the progressive vision offered by the book. I urge Freddie DeBoer to take developmental research seriously in the next revision of the book (starting here: https://www.karger.com/Article/Abstract/73306) as it will both strengthen the case for progressive educational policy with real empirical findings about individuals rather than the stale, banal, and un-actionable application of heritability estimates to educational outcome.
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