You thought your personality was a combination of biological inheritance and environmental and social outcomes? Prof. Plomin proves you wrong. In his latest book Blueprint: How DNA Makes US Who We Are, the world-renowned behavioral geneticists shows that DNA can predict from birth who we will become. Nature vs nurture.
As the memory of the past still casts a dark shadow upon genetics, Plomin’s book offers ‘eye-opening’ insights based on the lastest genetic tests and discoveries. This DNA revolution calls for a radical rethink of our system, from science and health, to society and education. One we should all be apart of.
Welcome to a brave new world.
Your studies have shown that the key to our personality traits lies in our DNA. “Environmental effects are important,” you write, “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.”
Could you give us a very brief overview of these discoveries?
Blueprint is the culmination of my 45 years of research trying to understand the genetic and environmental influences that make us different — our personalities, our mental health and illness and our mental abilities and disabilities.
I conclude that inherited DNA differences are the major systematic force, the blueprint, that makes us who we are as individuals.
Our experiences also matter — family, school and friends — but these experiences don’t fundamentally change who we are: we would essentially be the same person if we were cloned and our clone grew up in a different family, went to a different school and had different friends.
Environmental differences are important – they account for other half of the differences that are not explained by genetic differences – but these environmental differences are totally different from the way environmentalists thought they worked. From Freud onward, environmentalists assumed that the environment was doled out by families, as implied by the word ‘nurture’. Genetic research has shown that environmental influences are idiosyncratic, stochastic, and unsystematic – in a word, random.
‘Genetic research has shown that environmental influences are idiosyncratic, stochastic, and unsystematic – in a word, random.’
These findings call for a radical rethink about parenting, education and the events that shape our lives.
The most exciting reason for writing Blueprint now is the DNA revolution. In just the last three years, it’s become possible to use DNA itself to predict from birth who we will become.
This power to read our DNA blueprint will transform science, society and how we understand ourselves.
You mention several times in your book the importance of polygenic scores and tests. Could you tell us more about them?
The key to the DNA revolution is polygenic scores. About half of all individual differences in complex physical and psychological disorders and dimensions are caused by inherited DNA differences. However, these genetic influences are not due to a single gene or even a handful of genes. What we have learned in the last decade is that thousands of DNA differences are responsible for genetic influence on these traits. The DNA revolution has arrived because we can now add these thousands of DNA differences in composite scores to predict from birth who we will become. These composite scores are called polygenic (multiple-gene) scores.
It seems like a lot is already determined when we are born. Can we escape this DNA destiny?
Genetics is the main systematic force in shaping who we are as individuals, but genes are not destiny. Many times in Blueprint, I explicitly deny determinism, with statements such as ‘genetic research describes what is rather than predicting what could be’; ‘genetic influences are probabilistic propensities, not predetermined programming’, and ‘genes are not destiny’. I consistently use the verb ‘influences’ rather than ‘determines’, ‘causes’, or ‘hard-wired’. I talk about genetic influences as ‘nudges’ and ‘whispers’. I don’t say these things as a palliative, I mean them.
How do you see the role of parental education in this new scenery?
In terms of parenting, the most quoted phrase from Blueprint is ‘Parents matter but they don’t make a difference.’ The phrase ‘don’t make a difference’ is often misconstrued to mean ‘can’t make a difference’. ‘Don’t make a difference’ means that differences in parenting as they exist in the populations we study do not make much of a difference in children’s psychological outcomes. It is important to emphasise the caveat that this conclusion refers to the normal range of genetic and environmental influences, not rare genetic mutations that can have devastating effects, or severe abuse or neglect.
This is another example of the distinction between what is and what could be. For example, differences in parenting don’t make much of a difference in children’s outcomes in the normal range of differences in parenting as they exist in the populations we study. However, using extreme, highly authoritarian parenting techniques, it is possible that parents could push their children towards becoming what the parents want them to be – a musician, an athlete, or a scholar. Instead of preordaining what we want our children to become, why not go with the genetic flow? Try to find out what children like to do and what they do well and help them do it. Because, on average, parents don’t make much of a difference.
‘On average, parents don’t make much of a difference.’
Parenting is not a means to an end. It is a relationship, one of the longest-lasting relationships in our lives. Just as with our partner and our friends, our relationship with our children should be based on loving them, not changing them.
I am not advocating that parents should just let their children do whatever they want to do. Parents can and should control their children’s behaviour, for example, monitoring their children’s activities and setting limits on aggressive behaviour. But controlling children’s behaviour does not change who they are — their personality or mental health and illness. For example, zero tolerance of bullying in schools can wipe out bullying behaviour on the school grounds, but it doesn’t change bullies once they are freed from the control of school rules. That’s why we have laws in society. If you get caught drunk driving you will go to prison, but this law doesn’t change your genetic risk for alcoholism.
I hope this is a liberating message for parents. I think parents should relax and enjoy their relationship with their children. Part of this enjoyment is in watching our children become who they are genetically.
Apart from education, which fields should make the most of your studies?
Polygenic scores are already having a major impact on science and society. For example, they are transforming our understanding of disorders by shifting the focus to causes instead of symptoms, to dimensions rather than diagnoses, to individually tailored treatments instead of one-size-fits-all treatments, and especially to prevention instead of treatment.
The ability to read our DNA blueprint will transform health care because DNA is the only early-warning system that can predict problems at birth so that we can prevent problems from occurring, often using low-tech interventions.
For example, a polygenic score for cardiovascular risk can help to identify the 8% of the UK population with a genetic risk for heart attacks three times the population average. The fact that inherited DNA differences do not change throughout life means that we can predict and thus prevent heart attacks for people at high genetic risk. An ounce of prevention is worth a pound of cure; preventing one severe heart attack would save hundreds of thousands of pounds and the savings in quality of life is immeasurable.
Polygenic scores are a great opportunity for universal health care systems like the National Health Service in the UK. Universal health care shares genetic risks and costs across the population and should be motivated to promote health and prevent illness. In contrast, I wonder how insurance-based health systems can survive the DNA revolution, especially when hospitals are paid only for treating illness, not preventing it. In my view, universal health care is not some kind of a throwback to 1940’s idealism. It’s the only sensible way to provide health care in light of the DNA revolution.
‘Universal health care is the only sensible way to provide health care in light of the DNA revolution.’
What precautionary measures need to be taken before we can actually put your findings to practical use (even for the greater good)?
I’m a cheerleader for the good that can come from the ability of DNA to predict problems before they occur.
Polygenic scores represent a major scientific advance and, like all scientific advances, they can be used for good as well as for bad. In Blueprint I highlight their potential for good in science and society as an antidote to the dystopian doom and gloom that often permeate discussions of personal genomics.
Still, we need to discuss the pros as well as the cons so that we can maximize the benefits and minimize the costs, because the DNA revolution is unstoppable. Although there are many psychological and ethical issues to consider, millions of people have already voted with their credit card by paying to have their genomic fortunes foretold, even before polygenic scores are available. Genomics is here to stay. The internet has democratized information to such an extent that people will not tolerate paternalistic regulations that prevent them from learning about their own genomes. The genome genie is out of the bottle and, even if we tried, we cannot stuff it back in.
Now is the time to launch a broader public conversation about the applications and implications of the DNA revolution because it will affect all of us. The main reason I wrote Blueprint was to foster this discussion and to provide the DNA literacy that we need to address these complex issues in an informed way. Genetics is much too important to leave to geneticists alone.
‘Genetics is much too important to leave to geneticists alone.’
Have you ever worried that this could give rise to a brand new form of discrimination? Have discussions about eugenic issues ever come up?
In the months since the publication of Blueprint in October 2018, it has never come up in my many interactions with the public, although it is often raised by media.
In his review in The Times, David Aaronovitch said, ‘It does seem to me that all too often, critics of Plomin’s conclusions switch with too much alacrity from scientific arguments to ethical ones.’ An editorial in the journal Nature in 2017 concluded that modern genetic research should not be held back by its past. Indeed, this editorial suggested that ‘the nuances achieved by modern genetics can be used to dispel’ its historical abuses.
Totalitarian regimes like Nazi Germany do evil things, but they don’t need a rationale to do it. Nazis misappropriated genetics as a rationale to justify their atrocities. However, most totalitarian regimes assume an environmental rationale, that people can be molded as the state wishes. For example, Stalin’s USSR, the 1948 model for Orwell’s 1984, actively denied genetics and purged scientists who doubted the inheritance of acquired characteristics.
I hope that anyone reading Blueprint will see that my view is opposed to any totalitarian approach. I want to use insights from modern genetics to help people help themselves and their children reach their full potential and be healthier and happier.
Most rewarding have been my conversations with people during book-signing sessions and events. People are excited and enthusiastic. A typical comment, and one I love best, is that the book was an eye-opener. That is, people say they were not really opposed to genetic influences on individual differences, even for psychological traits. They just hadn’t known much about genetics so far, or seen its relevance for their lives.
In conclusion, Blueprint has done what I hoped it would do: launch a discussion about the applications and implications of the DNA revolution for science and society.