Gene for-tigue
March 9th, 2010
Scientists have found the gene for hat-wearing. They hope the discovery will help people with cocklaphobia – a fear of hats, by explaining why some people are drawn to donning headgear while others shun the habit. The researchers, from the University of Sans Fez in the US, studied 200 Asian and white men and women. They discovered that more Asian women carried the gene, which may explain why headwear is less popular in the West.
Ok, I made that one up. But it isn’t that far fetched, surely? After all, we’ve had a premature ejaculation gene, a gene for ear wax, a left-handedness gene, a Peter Pan gene for eternal youth and even a commitment-phobic gene. Nearly a decade after humans decoded their DNA, there’s an insatiable public desire to discover whether curls or cheating on our partners can be blamed on our genes. Which is why it’s a shame that this ‘gene for’ business is, in most cases, a pile of bunkum.
It makes sense when you think about it. Humans have around 20,000 genes. Now list all the health problems or personality traits people can have in alphabetical order. You’ll run out of genes long before the sporty gene or even the music gene. So the ‘gene for’ isn’t a gene at all. At best, it’s one short section of genetic code that affects whether we have, say, blue or brown eyes. And, in most cases, it isn’t even that.
Take, for example, the ‘gene for genius’. As Robert Plomin of London’s Institute of Psychiatry said: “this is not a genius gene. It is not even the gene for general intelligence; at most it is one of many”. With a moment’s thought, this too makes sense.
Intelligence isn’t a single, well-defined thing like the number three. We often imagine geniuses to be people wearing glasses who use big words and are good at tests. But passing tests needs several skills. For example, a good memory to remember our revision, motivation to revise and not watch TV, and an understanding of our revision. We might have to recognise shapes, add up or write about Shakespeare, depending on the test. Kim Peek, inspiration for the film Rainman, shows remembering facts isn’t the same skill as reasoning through problems. Born with brain abnormalities which hindered his reasoning, he nonetheless had an awe-inspiring memory. If intelligence needs several skills, why should it be affected by just one gene?
Intelligence or weight (the fat gene) are affected by many different genes, each with a small influence. For example, the ‘genius gene’ only accounted for 4 IQ points and the average person has an IQ of 100. As you might have guessed, genes don’t affect only one trait like intelligence. So the ‘genius gene’ might have more effect on something else that scientists haven’t studied yet (like risk of a cancer) than it does on brain power.
Imagine if the press reported: ‘Woman kills husband because he left toilet seat up’ and then further down the story: ’leaving the toilet seat up 4% of the reason why Mrs Smith stabbed her husband in brutal attack. But raised toilet seat 15% behind death of Smiths’ son in freak accident’. You’d feel disappointed and mislead – you might feel angry at the writer behind the story. So you should be with the ‘genius gene’.
But, if we found all the genes affecting weight, surely we’d know 100% of the reasons why people are fat? Then we’d know who is fat without looking. Wrong. We all know diet and exercise affect weight too – genes don’t determine what we do. They only affect likelihoods. If you have lots of ‘fat genes’, you might find it harder to lose weight than other people, but you’re not doomed to be fat. So commitment phobics and cheating hearts – genes are no excuse, but you could be more tempted than most.
Genes are sections of DNA that carry out a set of similar tasks. In some ways, they’re like household electricals. On a mobile phone you can make calls, keep a calendar and play a game. But you need a different device to make Welsh rarebit and a Sunday roast. The cooker and mobile phone are like two genes. This shows why a ‘gene for’ is absurd. You wouldn’t say ‘I have an appliance for coffee ice cream in my kitchen’ – fridges do lots of other things too.
If we download or delete ring tones, music or software for our phone, it differs slightly from the next person’s. Similar differences in our DNA – genetic variants – explain why why we vary in eye or skin colour. And genetic diseases like cystic fibrosis happen when there’s an error in our DNA. Just like a malfunctioning phone - sometimes there’s only one possible cause of the fault. But, other times, a repairman might spend time working out which component(s) have gone wrong. In the press, this is invariably reported as ‘a gene for cystic fibrosis’, even though 1000s of errors could cause the disease. It’s like writing ‘faulty screen causes mobile phone blackout’ – the more common cause is a flat battery.
If you’ve made it this far – to the end – you’ll know ‘gene for’ stories are the scientific equivalent of reports of celebrity love affairs. They’re usually inaccurate and not always as interesting as they sound. Do we need the stories reporting better? Or are genetic variants with 0.01% influence on X not news? Are the public gagging for this stuff? Or are ‘genes for’ now stories becoming as tiresome as Lady GaGa’s endless costume changes? Do we – scientists and the public – have gene for-tigue?
Scientists have discovered the gene for shyness – it was hiding behind a bunch of other genes
Categories: Short walks
Yes.
There is so much vacuous science reporting. And why? What is the cause? Is there a gene for it?