BBC Column: political genes

Here’s my BBC Future column from last week. The original is here. The story here isn’t just about politics, although that’s an important example of capture by genetic reductionists. The real moral is about how the things that we measure are built into our brains by evolution: usually they aren’t written in directly, but as emergent outcomes..

There’s growing evidence to suggest that our political views can be inherited. But before we decide to ditch the ballot box for a DNA test, Tom Stafford explains why knowing our genes doesn’t automatically reveal how our minds work.

There are many factors that shape and influence our political views; our upbringing, career, perhaps our friends and partners. But for a few years there’s been growing body of evidence to suggest that there could be a more fundamental factor behind our choices: political views could be influenced by our genes.

The idea that political views have a genetic component is now widely accepted – or at least widely accepted enough to become a field of study with its own name: genopolitics. This began with a pivotal study, which showed that identical twins shared more similar political opinions than fraternal twins. It suggested that political opinion isn’t just influenced by dinner table conversation (which both kinds of twins share), but through parents’ genes (which identical twins have more in common than fraternal twins). The strongest finding from this field is that the position people occupy on a scale from liberal to conservative is heritable. The finding is surprisingly strong, allowing us to use genetic information to predict variations in political opinion on this scale more reliably than we can use genetic information to predict, say, longevity, or alcoholism.

Does this mean we can give up on elections soon, and just have people send in their saliva samples? Not quite, and this highlights a more general issue with regards to seeking genetic roots behind every aspect of our minds and bodies.

Since we first saw the map of the human genome over ten years ago, it might have seemed like we were poised to decode everything about human life. And through military-grade statistics and massive studies of how traits are shared between relatives, biologists are finding more and more genetic markers for our appearance, health and our personalities.

But there’s a problem – there simply isn’t enough information in the human genome to tell us everything. An individual human has only around 20,000 genes, slightly less than wild rice. This means there is about the same amount of information in your DNA as there is in eight tracks on your mp3 player. What forms the rest of your body and behaviour is the result of a complex unfolding of interactions among your genes, the proteins they create, and the environment.

In other words, when we talk about genes predicting political opinion, it doesn’t mean we can find a gene for voting behaviour – nor one for something like dyslexia or any other behaviour, for that matter. Leaving aside the fact that the studies measured “political beliefs” using an extremely simple scale, one that will give people with very different beliefs the same score, let’s focus on what it really means to say that genes can predict scoring on this scale.

Getting emotional

Obviously there isn’t a gene controlling how people answer questions about their political belief. That would be ridiculous, and require us to assume that somewhere, lurking in the genome, was a gene that lay dormant for millions of years until political scientists invented questionnaire studies. Extremely unlikely.

But let’s not stop there. It isn’t really any more plausible to imagine a gene for voting for liberal rather than conservative political candidates. How could such a gene evolve before the invention of democracy? What would it do before voting became a common behaviour?

The limited amount of information in the genome means that it will be rare to talk of “genes for X”, where X is a specific, complex outcome. Yes, some simple traits – like eye colour – are directly controlled by a small number of genes. But most things we’re interested in measuring about everyday life – for instance, political opinions, other personality traits or common health conditions – have no sole genetic cause. The strength of the link between genetics and the liberal-conservative scale suggests that something more fundamental is being influenced by the genes, something that in turn influences political beliefs.

One candidate could be brain systems controlling our emotional responses. For instance, a study showed that American volunteers who started to sweat most when they heard a sudden noise were also more likely to support capital punishment and the Iraq War. This implies that people whose basic emotional responses to threats are more pronounced end up developing a constellation of more right-wing political opinions. Another study, this time in Britain, showed differences in brain structure between liberals and conservatives – with the amygdala, a part of the brain that learns emotional responses, being larger in conservatives. Again, this suggests that differences in political beliefs might arise from differences in emotional processes.

But notice that there isn’t any suggestion that the political opinions are directly controlled by biology. Rather, the political opinions are believed to develop differently in people with different basic biology. Something like the size of a particular brain area is influenced by our genes, but the pathway from our DNA to an apparently simple variation in a brain region is one with many twists, turns and opportunities for other genes and accidents of history to intervene on.

So the idea that genes can have some influence on political views shouldn’t be shocking – it would be weird if there wasn’t some form of genetic influence. But rather than being the end of the story, it just deepens the mystery of how our biology and our ideas interact.

11 Comments

  1. Posted December 11, 2012 at 3:47 pm | Permalink

    Great article, I particularly appreciate that you went back and gathered some context for the current lins of research.

  2. John Roth
    Posted December 11, 2012 at 7:46 pm | Permalink

    Excellent. Is there any reason why the word “refusing” appears at the end of two paragraphs?

  3. tomstafford
    Posted December 11, 2012 at 10:26 pm | Permalink

    @john, it must have been a copy/paste error when I was posting the article into WordPress. Thanks for pointing it out. And glad you liked the article

  4. Posted December 12, 2012 at 5:07 am | Permalink

    Hmmm I don’t know about this. But the identical twin study does seem to give it some validity. I know that I have shifted my politics through the years but this election have been more close to my roots. But I come from a very political family so there is influence there.

  5. Posted December 13, 2012 at 10:06 am | Permalink

    The assertion that there is simply not enough information in the human genome to “tell us everything” is trivially correct in one sense (in that the organism develops in an interaction with its environment) but quite mistaken in another, if you base it on the fact that we “only” have 20,000 genes, as if that meant there were only 20,000 bits of information in the genome. That’s like saying the works of Shakespeare have only 26 bits of information because they only use the 26 letters of the alphabet. The genetic program for development of an organism includes all the genetically encoded instructions for turning on and off all those 20,000 genes and entails the emergent properties arising from the myriad interactions between them.

    Regarding genetic influences on politics they start to look less outlandish if you think of them as affecting traits like harm avoidance, group loyalty, empathy, etc. You’re right of course that even these traits emerge over development as a person with particular genetics interacts with their social and cultural environment.

  6. Posted December 13, 2012 at 6:24 pm | Permalink

    It actually comes down to two structures in the brain that balance each other and which one is dominant. The amygdala handles threat assessment and has been found to be more developed in people with conservative leanings. The complementary structure is the anterior cingulate circuit, which modulates attention, but also seems to assist in seeing the shades of grey to an issue. This tends to be more developed in liberals. Behaviorally, this can be stregthened with such things as meditation and hypnosis. I’m not sure about strengthening the amygdlala, but there is tremendous plasticity to our brains, so I’m guessing it’s possible. Interestingly, as we age, statistically we become more liberal. This also corresponds to older adults having reduced ability for threat assessment (and becoming happier) with age.

    Of course, there is a genetic component to our brain anatomy, but nothing is fixed.

  7. tomstafford
    Posted December 14, 2012 at 7:34 am | Permalink

    @pause88 you speak about the brain with massively more confidence than is warranted by our current state of knowledge

  8. Raymond Zervaas
    Posted December 18, 2012 at 10:05 am | Permalink

    Well, with a bit of effort this should make a fine new entry in the next version of DSM :
    -POD
    Political Opinion Disorder, a neurobiological disorder (it shows up on fMRI) and genetic ailment, that affects almost 99% of the population. Finally an exciting new oportunity for the pharmaceuticals to develop the blockbusters of the future.

  9. Posted December 18, 2012 at 2:54 pm | Permalink

    wish you had a ‘like’ button – but then i would just wear it out!

  10. jhbombardier
    Posted December 20, 2012 at 7:31 am | Permalink

    Tom Stafford,

    I am writing this comment to you because I wish to communicate with you about a recent article about Hypnic Jerks, I don’t do Twitter and wish to communicate with via email.

    I am a 64 yr. old miracle survivor (am told) of a bicycle/SUV crash where I took the side mirror OFF with the back of my helmeted head at American highway speed 55mph….and am doing amazing well….6.5 years out now.
    That said for the past 19 months, recently mostly resolved, I have been experiencing a full body twitch when I tried to meditate or in some instances just relax. If you think that further information about my experience could be mutually beneficial, please contact me via email.

    Thank you for your consideration.

    James Bombardier

  11. tomstafford
    Posted December 21, 2012 at 11:30 am | Permalink

    James
    I am not a medical professional, and pretty much all I know about hypnic jerks is in the article you read, so for both these reasons, I doubt I can help. Apologies
    Tom


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