Friday, 5 October 2018

Nature versus Nurture

My sister had two children when she was quite young. With the second child she received - and listened to - advice to have the child adopted. It was an open adoption where the child knew about the adoption right from the start, and we kept contact in a kind of cards-and-presents-at-birthday-and-Christmas distant relative way in order to give the adopted family time to build sound relationships.

My sister's children did not met each other until they were 7 and 8 respectively. They had both lived incredibly different lives to that point: philosophically, environmentally, parentally and developmentally. They were both temporarily in the same city and - with permission - I introduced them to each other at a beach. I was forcefully struck... shocked, actually... by their mirror mannerisms, their identical turns of phrase, and their incredible similarity to each other. They were like peas in a pod. This was not a shared generational familiarity caused by having experienced the same kind of schools and growing up in the same country together at the same time: it was much stronger than that. This was close siblings who know each other intimately and live in each other's pockets.

To this point I had been a 'nurture' person. I didn't think that nature played much of a part in who we were and whom we would become. That one meeting began a paradigm shift in my views about the role of nature. Over the years, having watched the siblings do more or the same things at the same age - while noting that luck has played more of a part with one than the other - I have shifted my focus to nature being a significantly stronger force than nurture.

I have done a lot of reflection about family patterns since. In the leadership field, there is a great deal of evidence to say that nature is responsible for 40% of our leadership skill, and nurture for 60% (Jackson & Parry, 2011). Despite the evidence for 40/60, I 'believe' that we are influenced by roughly 90-95% nature and 5-10% nurture... from what I have seen in my family.

Which brings me to the purpose of this post. US-born psychologist, Robert Plomin, has just published a book, "Blueprint: How DNA Makes Us Who We Are" (UK: Allen Lane). His book proposes that “hereditarian” science is our strongest influence; that our biological DNA inheritance not only determines who we are, but also what we achieve; suggesting that our nature-influenced approach to education plays a much larger part in our lives than we would like to think. Andrew Anthony in the Guardian writes about an interview with Robert Plomin in which (29 Sep 2018):
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.
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. The larger the study group, the more accurate the predictions – and, as more and more people have their genome mapped, the study groups are growing all the time.
“We’re explaining more variance in GCSE scores than you can predict with anything else, including parents’ educational level and socioeconomic status,” says Plomin.
Robert Plomin and Andrew Anthony raise the spectre of Nazism: that if some have superior genes, then what does that do for the hope of the remainder? Robert Plomin talks about needing not only the courage to speak out in a climate which is equality and nuture-focused, but for the possibility of the idea of heritability to be investigated with less bias and political fear. The issues of right-wing ideological focus is considered for its impact on whether the poor are poor because they have poor genes, so we needn't invest in them, versus the left-wing opportunity to target those who will have learning difficulties early and work on bringing them up to speed. They also talk about the potential reaction to hereditarianism within academia: it is likely to be an unpopular hypothesis.

I understand their caution, and the skepticism of those working in this field who may be seeing our global 'self-made man' story potentially being deconstructed. However, I feel that having an understanding of heritability could make us more vigilant about educating children about the family foibles that may trap them at certain times of their lives, and so reduce the likelihood or impact of bad choices at times of high risk. If this research over time is shown to be legitimate, our education systems could be much more targeted in ensuring that all of us could succeed despite our genes.

I wouldn't underplay the strength of a mere 5%. I have personally seen that change lives.


  • Anthony, A. (29 Sep 2018). So is it nature not nurture after all? The Observer Science Column. Retrieved from
  • Jackson, B. & Parry, K. (2011). A Very Short, Fairly Interesting and Reasonably Cheap Book About Studying Leadership (2nd ed.). London, UK: Sage Publications Ltd.  

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