Robert Plomin



After my 50 years of research on this topic, I have concluded that inherited DNA differences are the major systematic force making us who we are as individuals – our personality, our mental health and illness and our mental abilities and disabilities.

Robert Plomin is an American-British behavioral geneticist who advocates a high heritable component to differences in human behavior and health outcomes, which some have described as advocating strong biological determinism, or at least an overemphasis on genetic factors.

Bio-determinism
Plomin's work has focused on the heritability of differences in intelligence and academic outcomes and his view that the differences are largely genetic in origin.

, a sociologist and critical race theorist describes Plomin's practices (as far as racial implications go) as racial inexplicitness, a tactic of advancing racist policies without directly mentioning race. Gillborn continues:

However, Plomin didn't endorse The Bell Curve's conclusions on race and intelligence, and later described them as bizarre and not what he would have taken from the relevant data in an interview with the BBC. Plomin professes to be agnostic on the cause of ethnic differences in IQ, and rejected the notion a hereditarian view is supportable by the current evidence. He has said he supports further research on the causes of the differences, which earned him criticism from Gillborn.

He has been strongly criticized for partnering with Steve Hsu, a racist who was later dismissed from his position at MSU after making false claims about race and IQ and misrepresenting scientific papers, who was previously a leading figure of China's eugenicist embryo selection program, the goal of which is to find the alleles associated with intelligence in order to select for embryos who are more likely to have higher intelligence. . Human Genetics Alert, May 13, 2014. Despite partnering with him, Plomin opined that pro-eugenic statements made by Hsu and others had been unhelpful to research on discovering genetic factors behind human cognitive profiles.

However, claims that a hereditarian stance on genetics playing a role in intelligence is equivalent to or implicitly intertwined with racism does not appear to be justified, since the its acknowledged anywhere between 30 and 80 percent of the variation in IQ scores is determined by genetic factors, with 50 to 60 percent being the most commonly accepted range by experts, and since genetic heritability does not give credence to racial hereditarian claims about the genetic influence on group differences. Race is generally a social category and mostly irrelevant towards genetic differences, since race is based on many superficial physical traits and does not necessarily correspond to real genetic populations. More importantly, a generalized heritability estimate is based on a general population sample and says nothing about individuals or subgroups. Plomin has disavowed claims that there is any good evidence of group differences being caused by genetics, saying "No, they are not right. Individual differences in IQ can be highly hereditary; at the same time, the difference between migrants and natives can be entirely due to the environment. For example, because of their origin, migrants only get bad jobs, they attend worse schools and are discriminated against in other ways." This is because heritability estimates change with environmental differences. The heritability of IQ could be 60%, yet the differences between ethnic groups purely environmental since marginalized ethnic groups do not have the same resources as the dominant majority and may suffer from societal discrimination and other stressors which have been proven to reduce IQ scores.

Plomin gave a talk in 2018 at The Royal Institution where he argued "that our genes are the single most powerful influence on the type of person we are."

Twins Early Development Study
He until recently conducted the ongoing TEDS study of all twins born in England and Wales between 1994 and 1996, which he founded and then ran for 25 years. The data was provided by UK's Office of National Statistics. The study was undertaken by the Department Of Twin Research & Genetic Epidemiology at Kings College London and funded by the UK Medical Research Council. The focus of TEDS was on cognitive and behavioral department with special attention paid to abnormalities in the development process. Plomin retired from the project in 2021 and was taken over by Thalia C. Eley. The next phase will focus on the children of the twins with an emphasis on mental health.

Blueprint
In 2018, the MIT Press published his Blueprint: How DNA Makes Us Who We Are, which promotes his biological determinist views. It was critiqued in some outlets such as Logos. In Scientific American, later commented: Robert Plomin is a legend. For over 40 years he has been on the forefront of our understanding of the genetic and environmental influences on human behavior. Based on his groundbreaking work on twins, he showed that genes really do have a substantial influence on our psychological traits-- we are not born a lump of clay. [...] All of this makes it rather bewildering that, ever since his book Blueprint: How DNA Makes Us Who We Are came out, he has been spreading a lot of outdated misinformation in the media that is not supported by the latest science of genetics, including his own work. Also, many of his statements have been riddled with contradictions and logical non sequiturs, and some of his more exaggerated rhetoric is even potentially dangerous if actually applied to educational selection.

Even The Spectator, a right-wing magazine known for publishing defenses of various fascist groups in the past, featured a piece by psychologist and behavioral geneticist (who herself published a book about the genetic influence on life success, albeit from a self-professed progressive/humanitarian perspective on how to best accomodate those factors), who attacked Plomin's over-emphasis on genes (in which he speaks of DNA as a "fortune teller") versus environment (which he radically downplays). (Based on some other statements by Plomin, e.g. "Environmental influences are important, too, but they are largely unsystematic, unstable and idiosyncratic." Harden may have strawmanned him).

However, others have claimed that the criticism of Plomin is unwarranted or overstated. A 2018 publication in the European Journal of Human Genetics wrote "Plomin is clear that for each complex trait studied, genetic factors can only explain about half of the variance observed." Geneticist Barbara Jennings wrote "Blueprint has been criticised for being a manifesto for genetic determinism, but in my opinion that is a misreading of the book". Leon Vliegar, a biologist at the Department of Biosciences, University of Helsinki, gave the book positive reviews and stated that in his opinion "what increases Plomin’s credibility in my view, is that he acknowledges all of this troubled legacy. He admits that some of what he writes will be controversial to some, but he avoids hyping things. He openly confronts the reproducibility crisis and shows how, at least in the field of behavioural genetics, it came about and is now being resolved."

Plomin does not totally discount environmental contributions. He advocates for policy changes to address environmental factors, and on page 32 explicitly writes that environment does matter. He also advocates that attempts to decrease systemic inequality in education should focus on reducing environmental disparity and acknowledges that policy can shape environment. . He also acknowledges the effects of environmental changes on physical health. However, Jonathan Kaplan, writing in Literary Review gave his opinion that while Plomin's enthuasism for his field can be fascinating, "[...]that enthusiasm sometimes gets the better of him: the book glosses over too many of the weaknesses of human behaviour genetics as it is currently practised and Plomin sometimes makes claims that, even if technically true, are at the very least deeply misleading."

A 2019 review published by Cambridge University Press gave mixed reviews, noting that "A major strength of this book is that one of its main take-home messages is that genetics contributes to all our traits and behaviors.". However, it also claimed that Plomin's reduced discussion on non-genetic factors can be harmful. It noted that some of the implications of the book can be positive for "early identification of disease risk, the discovery of disease pathways that could serve as targets for invention" as well as the idea that traits like obesity and other stigmatized traits have components that the individual may not have control over. On the other hand it claimed that negative stigmatization and discrimination could also result from an over-emphasis on genetics, and also notes that mechanistic studies of the Developmental Origins of Health and Disease shows that the recent rise in communicable diseases has a large environmental component, which has been understated by Plomin. It also noted studies show the public better responds to emphasis on both genetic and environmental factors that influence health, as opposed to emphasis on genetics or environment alone, so Plomin missed out on an opportunity to communicate to the public by neglecting non-genetic factors.