The lazy gene: in which I review a nature versus nurture debate six years late


This is another archive repost from the old blog, written in aug 2008.

The psychologist Oliver James was on The Late Edition a couple of weeks ago.[1] His argument was unconvincing and his behaviour unimpressive. So I took a quick look at his website. He offers for download a Radio 3 Nightwaves debate on “nature versus nurture” with James, Steven Pinker, Hilary Rose and John Gray from 2002. Always at the cutting edge, I thought I’d take a listen.

What an utter waste of airtime.[2] Anybody who knows a good chunk of background on the subject would just have heard some people sitting around having an over-the-top argument over trivial matters. But if you don’t know the background, you could very easily get the impression that the argument was over something fundamental — especially considering all of the appeals to consequences that were flying back-and-forth. One camp arguing fiercely for nature and the other arguing fiercely for nurture. The root of the problem? Nobody thought to explain that they were arguing about the cause of variation in behaviour, not the cause of the behaviours themselves. Nobody ever seems to do that when discussing “nature versus nurture,” yet these four academics must be aware of the difference, and how misleading it is to conflate them. Pinker stated that genetic determinism is a myth, while Rose pointed out that nobody has believed in the “blank slate” for a century. But this was as close as they got to acknowledging the true nature of development. I know that Pinker did eventually make the point in The Blank Slate, the book he was promoting at the time of the debate, but it was buried somewhere near the end.

Perhaps if every discussion of the topic came with some sort of disclaimer, or started with a basic introduction, a lot of misunderstanding and unnecessary shouting would be avoided. Here’s my proposal for it: there is no nature versus nurture problem. All traits — physical and behavioural — require a certain set of genetic and environmental conditions. All characteristics have many diverse and variable influences. All personality quirks, preferences, and even diseases require just the right nature and nurture in order to develop. Even when things go wrong, our biology is contributing something: if (contracted(disease)) die;.

When people argue over nature and nurture, the argument is over which is behind any between-individual (or between-population) variation in the trait in question. Sometimes we can agree that one-or-other factors is trivial — the death certificate of a traffic-accident victim will never list “lack of hard-exoskeleton” as cause-of-death — because there is no significant or relevant variation in it. But in more cases than you might imagine, it is important to consider both sets of conditions.

Lets illustrate this to the point of absurdity. We’ll compare HIV/AIDS and severe combined immunodeficiency (SCID).[3] When comparing the immune systems of healthy and HIV positive individuals, the variation has a clear causal relationship with environmental variation; when comparing the immune systems of healthy andSCID individuals, the causal relationship is with a genetic variation. So is immunity genetically determined, or environmentally determined?

But SCID has an environmental component! It is only in the context of pathogens that people die from SCID. And HIV has a clear genetic component! HIV can wreak havoc only in the context of human biochemistry and cell biology. But stop the presses! We already know of some people who are naturally more resistant to HIV. In areas with little medical intervention, genetic variants conferring resistance to HIV are almost certainly at a selective advantage and will increase their frequency in such populations. Suppose that one day 999 in 1,000 people have inherent resistance to HIV — carrying and transmitting the virus, but living perfectly healthy lives with no need for medical intervention. How do we then categorise HIV/AIDS on the nature-nurture dichotomy?

These diseases are, of course, extreme examples which are far removed from normal developmental processes, but they illustrate how a great many variables affect each phenotype — and that’s just when things go wrong. Unfortunately, so long as people continue to believe that this argument has consequences, they will continue arguing vociferously. From “gay genes” to “god genes”, too many people are convinced that nature versus nurture is an important debate.

In summary: if I were Oliver James, I wouldn’t be advertising the debate at all. Leaving aside the general pointlessness of it, he comes over as an even bigger arse than he did on The Late Edition. The fact that he confuses The Selfish Gene with evolutionary psychology sums up the value of his argument.

Footnotes

  1. ^ Yes. Yes, I did start writing this post in early March. Yes, it has taken me nearly six months to get around to writing the second half and publishing it. Whatever.
  2. ^ I know, what was I expecting from a programme featuring Hilary Rose?
  3. ^ I know, I know, these do not reflect normal development, and are only superficially comparable diseases. It’s just that normal development is so much more subtle: when I needed a crass example that spelled things out, this was the first that came to mind.

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