Blueprint, by Robert Plomin. Genetics, free will, and what is seen and what is not seen

What you see is not what you get

Most of what we believe about the world is based on a naive realism: we see things and assume they are important. You might call this availability bias. So, for example, lots of people believe that reducing plastic bag usage and eating locally-sourced food will reduce their carbon footprint. Those things make very little difference: the real difference comes from vegetarianism and flying less.

Weirdly, although I make far less effort than most people I know to reduce my carbon footprint, my life in the last few years means I’ve probably done way more towards it than those others.

This is the difference between what is seen and not seen. My slightly carefree attitude to plastic bags is right there in front of you. (Reducing bag use is good, just not for reducing CO2 emissions). The data about what makes a difference is less visible.

Side note: cynics might say that vegetarianism and flying less are quite difficult, they involve a lot of pleasure loss; using fewer plastic bags is way easier, especially if you campaign for them to be taken away.

This is the ‘What you see is not what you get’ principle. It’s an old idea, but it just got a massive new application in the form of Behavioural Genetics, which is a field whose time has come and which will eventually be seen for the revelation that it is.

Genetics: what is not seen

Robert Plomin, Professor of Behavioural Genetics at King’s College, last year published Blueprint, which summarises the findings of his and others work in the last fifty years which have established the essential role of genetics in understanding our behaviour.

This field has come to some basic principles, backed up by immense amounts of replicated data, such as:

• All psychological traits show significant and substantial genetic influence
• No traits are 100% heritable
• Heritability is caused by many genes of small effect
• Phenotypic correlations between psychological traits show significant and substantial genetic mediation
• The heritability of intelligence increases throughout development
• Age-to-age stability is mainly due to genetics
• Most measures of the “environment” show significant genetic influence
• Most associations between environmental measures and psychological traits are significantly mediated genetically
• Most environmental effects are not shared by children growing up in the same family
• Abnormal is normal

These principles give us a new perspective on big questions of philosophy, politics, ethics and identity. They are hugely important. They establish what Plomin calls the blueprint theory: genetics are not destiny, but they are a huge, unavoidable set of parameters we are born with. They change the probability we will be overweight, happy, successful or tall.

They show us that everything is not in our control: they range and types of choices we have are different to what we hoped.

One of the biggest areas this work challenges standard beliefs on is education. Let’s take the example of reading fluency and phonics as a starting point.

The genetic relation between reading familiar words and non-words is 0.9.

That means that of the children who can read familiar words fluently and can also read non-familiar words easily, 90% of that ability is based in the same genetics. If you have the genes for reading familiar words you also have the genes for reading unfamiliar words.

Those two things are thought to be separate neurocognitive processes and are tested separately in schools. And yet, they are not fundamentally separate. Good at one, good at the other.

Similarly, skills like reading and maths show a genetic correlation of 0.7. The idea that most people are good at one or the other is simply wrong: people who are good at one tend to be good at both.

Neither of these things is obvious to us from what we can observe in daily life. We think we see something that isn’t really there. It might be there in some people or over the short term, but it isn’t the fundamental.

This is a more general point. Most people think 29% of the difference between individual’s school achievement is genetic. Test performance is actually 60% heritable. (Similarly, people think 40% of weight difference are heritable, whereas the true number is 70%.)

Here’s another one most of us instinctively find hard to accept:

The Ofsted rating of school quality explained less than 2% of the variance in GCSE scores after correcting for students’ achievement in primary schools.

In a world of universal education, heritability is the main thing that makes a difference to your school outcomes. That may not have been true a hundred years ago, but attitudes about the environment have failed to keep track with our knowledge of heritability.

Heritability and environment

This does not mean that 60% of your exam scores were ’caused by genetics’. Heritability measures how much of the differences between individuals are due to genetics. Some people will have many more of the genes associated with higher intelligence or weighing more than others.

What Plomin is arguing is that much of the differences between us are because of the differences between our genetics rather than our environments.

A rule of thumb for this sort of thing is that of all behavioural traits, about half of the differences between people are heritable.

Those of you who are now clinging to the idea that the environment accounts for something and can have sizeable effects on outcomes are in for a shock.

genetics was largely responsible for the association between parental negativity towards their children and their children’s differences in their likelihood of becoming depressed… In other words, parental negativity was a response to, rather than a cause of children’s negativity.

This illustrates the idea of the ‘nature of nurture’, which is that your genetics change the environment you are in and how you react to it. Even the personality trait agreeableness ‘shows no influence of shared environment.’

Here’s another way of putting it:

Growing up with a sibling does not make you similar to them beyond the similarity due to genetics.

There are things that shared environment affects: 20% of school performance and intelligence variations seem to be due to shared environment, and the same is true of some religious and political beliefs.

Living from our blueprint

So when we think about environment, we need to remember how difficult it is to measure, how flawed many of the current explanations are. We are often chasing a magic-bullet explanation or a self-help technique, that simply isn’t there. We are what we are.

What’s left to the environment is a lot smaller, a lot more random and much less systematic. Genetics increase with significance as you age. Environmental effects wear off. Think of all those piano students who never play a note after they leave school.

Perhaps the biggest one is luck. If you have genetics for high intelligence and you were born in a rich country with universal education rather than a poor country with variable education, you have got a good measure of what environment offers. Similarly, a good way of making a lot of the world’s people twice as well off as they are would be to drop them into New York, London, Singapore etc.

Like genetics, luck goes unseen. The things that didn’t happen to us might be just as important as those that did. We all see the differences in schools and homes and draw supposedly obvious links: but those links are most likely coincidences rather than causes.

What’s really going on is much less in our control than we think. Of course, there are obvious examples where this isn’t true. There’s no genetic explanation for the difference outcomes between men and women or between people from difference races. The effect size of the differences simply can’t explain that.

But when we are thinking about individuals we now have to think of them as coming with a blueprint. This shift is big. It’s much like it must have been for people thinking about evolution: imagine no longer being able to believe you were made of God, but were instead a higher ape.

We can no longer believe in ourselves as malleable, Freudian beings. It’s simply not possible to ignore the fact that twins reared apart bear almost no similarity to their adopted families and huge similarity to each other, even on measures like weight.

There are however lots of competing explanations that use the immediacy of our experience to try and explain things is an environmental way. However, those ideas are less robust than heritability.

Behavioural genetics is hugely robust, based on large, longitudinal twin and adoption studies. The ten principles I listed earlier have been replicated and replicated. And heritability explains huge, huge amounts of the variation.

Signifiant and effective

This is where effect size comes in to play. Effect size measures how much difference something makes. The examples written about here are that 70% of weight variation is heritable. 70% is a lot. Almost all psychological effects are in the order of 5% or less.

Much of what we read about in psychology that is presented as being significant simply isn’t very big. The results are statistically significant, but the effect size means whatever it is being studied only explains a tiny amount of the variation between people, if any. Many of the studies about priming or whatever else, which we want to use to build the case for the environment, are statistically significant results about practically insignificant things.

There’s also the problem of study reliability. We are in the middle of re-evaluating the extent of behavioural science’s conclusions. For example, the idea that making a test harder to read improves people’s performance, something Malcolm Gladwell said was true, simply isn’t. The original studies were small and badly performed.

Similarly, the famous Claudia Goldin study about blind auditioning women for orchestras, which almost everyone knows and believes, turns out to be far less conclusive than originally though.

It’s not even clear that loss aversion is true. That was one of the most widely accepted principles of the new behavioural science.

Growth mindset is probably untrue, or at least tiny.

What the team found was there is a correlation between someone having more of a growth mindset and doing well academically. However, the correlation is small and the findings do not support claims that growth mindset interventions have profound effects on academic achievement.

Pop-psychology has popularised many concepts that don’t have the sort of evidence base needed to be the basis of such general claims:

There’s social priming, where subliminal exposures can influence our behavior. And ego depletion, the idea that we have a limited supply of willpower that can be exhausted. And the facial-feedback hypothesis, which simply says that smiling makes us feel happier.

One by one, researchers have tried to repeat the classic experiments behind these well-known effects—and failed.

Many of the studies that give us ways of hacking life to “improve” ourselves simply aren’t reliable or don’t explain very much of the overall effect.

If we are going to make any use of the levers available to us from psychology and politics to change the way our lives end up we have to do so understanding our genetic blueprint.

Free will and genetics

This is major empirical justification for the philosophical idea that ‘you cannot be the cause of yourself.’ In some ways that’s self-evident. We are all the result of the genes our parents passed on to us. As Galen Strawon said, ‘the basic argument against ultimate moral responsibility works whether determinism is true or false.’ Genetics doesn’t add much here.

But heritability and the idea of a blueprint means we also cannot be the cause of ourself in a more significant way. We are not fully able to choose who we are. Our genetics mean we start with a set of predispositions, limits on what we can be. The old cliché that we can’t all be rocket scientists actually goes much deeper.

Imagine you had most of the genes associated with being overweight. This is not destiny: you may or not be overweight depending on the environment you are in. But it makes it significantly more difficult for you to stay slim.

This is no longer just a discussion of discipline and will power. It’s about the odds you start with.

Similarly with education. There is a persistent idea that two things can improve your educational outcomes: being in a better school and working harder.

Again, this is not really true. If it were, we would expect pre-school education to make a significant difference to long-term educational outcomes. Sadly, this is not the case.

the studies find that the educational parts of preschool are not useful, and better teachers and curricula do not affect the benefits. This strengthens rather than weakens the case that academic achievement is related primarily to IQ, and that IQ is primarily genetic and difficult to change.

The benefits of pre-school accrue to children from lower-income families because they get a more stable environment than they otherwise would have done, which is entirely consistent with the earlier discussion of universal education.

But this doesn’t mean there’s nothing in your control. It just means you have to think about managing yourself, rather than fundamentally changing. See your personality are closer to weight: it is in your control, but less than you thought.

Be conservative, not depressive

There are no definitive implications of all of this. It doesn’t mean we ought to make certain political decisions, for example. Nor does it justify any particular social policy. People worry about eugenics, but Plomin advocates for the NHS doing free genetic sequencing on everyone to improve preventative healthcare for major issues like heart disease and diabetes,

But I think it does reinforce a basic principle of conservative thinking: the world is what it is. That might change and improve, but it is not endlessly malleable. Out of the crooked timber of humanity nothing straight was ever made. We ought to prefer present laughter to utopian bliss. And we ought to focus on the improvements we can make, not our shortcoming against ideals.

The major implication is to worry less. Parenting and school matter but they don’t make much difference, as Plomin says. So enjoy it, don’t stress it. You aren’t going to be unrecognisably different after years of trying, so enjoy life more. Fat people are less to blame than you think, so start being nice to them. Ultimate moral responsibility is a difficult concept, unlike proximate responsibility, so see wrongdoing as a sorrow as much as a sin. Hate the sinner not the sin.

The second implication is to be practical. You can’t turn a Ford into a Rolls-Royce. But you can tune it up and refit it a hell of a lot. Much can be achieved with what you are. You might have to find unconventional paths to your goals, but they are not denied you. This is about probability, not possibility.

An epistemology of probabilities is implied by all of this. Be evidence led, not instinctive or anecdotal. Don’t make comparisons from your life in order to test your beliefs. Most importantly, don’t despair. This is not about denying your ability to control things. It’s a realistic wake-up call. You have choice, not just choice about all the things you thought you did. Learn to choose better. Look out for what is not seen.

Why this might be wrong

Here’s Arnold Kling giving the other side of the argument, which is essentially that Plomin has under stated the case for the environment.

I wish that Plomin had done a better job of anticipating criticisms of various sorts. For example, “Flynn” does not appear in the book, even though the Flynn Effect, which is a finding that IQ has risen over time, suggests that environmental effects do in fact matter for psychological traits.

In fact, it is difficult to dismiss the significance of what might be termed macro-environmental effects. For example, Plomin wishes to claim that genes account for all the systematic variance across individuals in years of schooling. But clearly there are differences across countries or across generations. It is not plausible to deny any systematic environmental effects whatsoever.

Kling also questions how well Plomin’s theories will hold up once we get more results from actually measuring the genome, rather than relying on twin studies and adoption studies.

Where to find out more

Blueprint, (US link), by Robert Plomin, is the book that informs most of this post. It is excellent, concise and about as important a book on science that has been published for many many years.

Plomin has been on many podcasts. I listened to more than half a dozen and they were all excellent. The best for a review of the arguments rather than the facts was HardTalk.

Another good book on behavioural genetics was Selfish Reasons to Have More Kids (US link) by Bryan Caplan. He is, in general, a much bigger believer in free will than I am. On this point I think he disagrees with Plomin, specifically about non-shared environment, but I haven’t seen him say that in those terms.

You should also read Dominic Cummings’s blog. He advocates for Plomin’s position that everyone should be able to have free genetic sequencing, which would massively improve healthcare provision.