Nature versus nurture – or genes versus environment – is one of the oldest debates in science. Indeed, it’s older than science itself.
As a reaction against the eugenic obscenities of the 20th century, we tend to resist the idea that our aptitudes, achievements and personalities are substantially influenced by genetic inheritance. And yet, the accumulation of hard scientific evidence would suggest that we are wrong to do so (albeit for the right reasons).
That evidence informs a new book – Blueprint: How DNA makes us who we are – by the geneticist Robert Plomin.
If you don’t have time to read the book, then read Andrew Anthony’s article about it – which is remarkable not just for the even-handed clarity with which it introduces Plomin’s arguments, but also for where it appears: the Guardian.
That the house journal of the liberal Left is giving Plomin a fair hearing is a sign that we might just have a sensible discussion about the science – and its implications. This is not before time:
“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’.”
Plomin is clear that genetic influences play a much bigger role in differences between individuals than is generally supposed, but there are important subtleties in his argument.
For instance, he’s certainly not claiming that there is ‘a gene’ for each of the complex behavioural traits he’s talking about:
“…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. No one yet understands the complex relationships between different genes, but Plomin points out that this is not necessary for predictive purposes. Polygenic testing, he says, comes up with heritability estimates that correspond to a whole range of physical and psychological traits.”
As with most complex matters, the new genetics is much more about probabilities than certainties.
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Of course, scientific subtleties tend to get lost when interpreted politically. And, as Andrew Anthony points out, there’s a definite Left-Right split in these interpretations:
“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.”
But maybe the ideologues have got it wrong.
If differences in certain abilities are, in large part, genetically determined, then surely that ought to mean less blaming of individuals (and their family and social backgrounds) for negative life outcomes. After all, sane societies don’t blame people for their inherited medical conditions.
Also, if we become more inclined to recognise ‘hardwired’ differences in particular aptitudes, then perhaps we’ll be less inclined to force people to compete in systems built around a very limited range of pathways to success (the education system being an obvious example).
Could this line of reasoning be used to sort the population into genetically-determined castes – like the Alphas, Betas, Gammas, Deltas and Epsilons in Aldous Huxley’s Brave New World?
Certainly, we should always be on our guard against the distortion of science – but, far from suggesting a crude stratification of society, the new genetics is all about the manifold interactions between thousands of genetic and non-genetic factors. Such complexity underlines our individuality. Therefore, if the science does suggest a particular policy direction, it is towards the personalisation of services provided to each individual – whether that’s in healthcare, education or any other form of support.
Ultimately, we don’t get to choose the scientific realities of the human condition. It is what it is. However, how we deal with those facts is our choice.
We don’t choose our genes (not yet), but we do choose our values.