From 2018:
So is it nature not nurture after all?
"Traditionally, those on the left have tended to see the environment as the critical factor because it ties in with notions of egalitarianism. Thus inequalities, viewed from this perspective, are explained not by inherent differences but by social conditions.
Similarly, those on the right have leaned towards a more Darwinian conception, in which different social outcomes are accounted for by differences of suitability to the environment...
In common with many other scientists, Plomin believes that Freud sent society looking in the wrong place for answers to the question of what makes us as we are. The key to personality traits does not lie in how you were treated by your parents, but rather in what you inherited biologically from them: namely, the genes in your DNA.
He finds that genetic heritability accounts for 50% of the psychological differences between us, from personality to mental abilities. But that leaves 50% that should be accounted for by the environment. However, Plomin argues, research shows that most of that 50% is not attributable to the type of environmental influences that can be planned for or readily affected – ie it’s made up of unpredictable events. And of the environmental influences that can be moderated, much of it, he argues, is really an expression of genetics.
As Plomin writes: “We now know that DNA differences are the major systematic source of psychological differences between us. Environmental effects are important but what we have learned in recent years is that they are mostly random – unsystematic and unstable – which means that we cannot do much about them.”
Plomin has been waiting 30 years to write Blueprint. It has taken him that long to conduct the research – much of it based on long-term twin studies – necessary to prove his case. But there was another reason for the delay, he admits: “cowardice”. For a long time, he says, it was “dangerous” to study “the genetic origins of differences in people’s behaviour and to write about it in scientific journals”...
“Genetics articles – I mean it was verboten, really, in the 1970s. Everything was environmental. Even schizophrenia was thought to be due to what your mother did in the first few years of life. It seems ridiculous now, but that was the orthodoxy back then. And to mention genetics was just beyond the pale.”
Within the world of science and psychology, he says, there is no longer any problem. But if you move out into other disciplines – he cites education as an example – “genetics is still the devil”. That said, he says brightening, it’s been decades since he’s been called a Nazi.
Ever since the development of genetics a century and a half ago, the discovery of DNA’s double-helix structure 65 years ago, and the mapping of the human genome 15 years ago, there has been an awareness that science was delving into secrets of Promethean flammability. While there has always been widespread acceptance that genes determine our physiology for good and bad, much greater controversy has surrounded the subject of our psychology – our behaviour and personality traits...
Plomin’s argument is that, in a society with universal education, the greatest part of the variation in learning abilities is accounted for by genetics, not home environment or quality of school – these factors, he says, do have an effect but it’s much smaller than is popularly believed.
Another problem that Plomin encounters with explaining his findings is that people often confuse group and individual differences – or, to put it another way, the distinction between means and variances...
“The causes of average differences,” he says, “aren’t necessarily related to causes of individual differences. So that’s why you can say heritability can be very high for a trait, but the average differences between groups – ethnic groups, gender – could be entirely environmental; for example, as a result of discrimination. The confusion between means and variances is a fundamental misunderstanding.”
For much of the relatively brief history of genetic science, there has been an even greater misunderstanding – the notion that the presence or absence of single genes is the determining factor that accounts for illnesses, abnormalities, dysfunctions, etc. Hence, some environmentalists have demanded to be shown the gene for various complaints and, when it is not produced, declare that there is no genetic explanation. But single-gene conditions are rare and, as far as anyone knows, nonexistent in psychology.
The big breakthrough in the past few years is polygenic testing, which is able to correlate multiple genes – often thousands – with behaviour differences...
“We’re explaining more variance in GCSE scores than you can predict with anything else, including parents’ educational level and socioeconomic status,” says Plomin...
A further argument made in Blueprint is that even those effects that are environmental may also be genetically influenced. This is what Plomin refers to as the “nature of nurture”. If we look at the correlation between parental socioeconomic status and their children’s educational and occupational outcomes, the tendency is to see it as environmental – better-educated parents pass on privilege, thus limiting social mobility.
But genetics, writes Plomin, “turns the interpretation of this correlation upside down”. Instead, the socioeconomic status of parents might be viewed as a measure of their educational outcomes, which are heritable. So children benefit from their parents’ genes more than from their socioeconomic privilege.
James believes that if, as a society, we accept the heritability argument, then it will lead to blaming the poor for their own plight and privileging the rich for their good fortune. He’s not alone. The Guardian ran an editorial earlier this year in response to a paper that Plomin (and others) published in which they stated that: “differences in exam performance between pupils attending selective and non-selective schools mirror the genetic differences between them”. The editorial described Plomin’s ideas as “pernicious and incendiary”...
“There are no necessary policy implications of finding that genetics is the major systematic force making us who we are. Rightwing values might lead someone to say that we should educate the best and forget the rest, but my view is that the intellectual capital of a society depends on the many not just the few. Leftwing values might lead someone to say that we should put whatever resources are needed to bring children who didn’t draw good genetic cards at conception up to minimal levels of literacy and numeracy needed to participate in our increasingly technological world.”
If we do manage to iron out environmental differences, Plomin notes, we then have to accept the genetic differences that remain. Because, the more we reduce environmental differences, the more we highlight genetic differences. In other words, if we want equality of opportunity, then the price is having to acknowledge a genetically loaded inequality of outcome.
The psychologist believes that we have to go with the science, not settle on a story that suits our political sympathies. “It’s better to be right than wrong,” he says.
Perhaps the most radical aspect of Plomin’s findings has little to do with the issue of equality, but instead seeks to rethink our treatment of mental health. At the moment, mental health follows the classical medical model by diagnosing a disorder and then seeking to deal with its cause. But genetic research suggests there are no clear lines in mental disorders, rather a spectrum on which we are all genetically placed...
Plomin believes that psychiatry is already adjusting to the findings by reclassifying some disorders as spectra; for example, schizophrenia spectrum disorder and autistic spectrum disorder. “Spectra,” he says, “is another word for dimensions.”"
Too bad it's now dangerous again. And now talking about genes
determining even physical differences can be dangerous too, as with trans mania (not that it wasn't in 2018 - saying that certain ethnic groups do better in some sports because of genes wasn't kosher then either)
