Consuming Issues: Hey big spender, it's all down to your genes

If you love chocolate, like me, you may be able to blame something other than considerable greed if you no longer fit into your jeans: your genes. Research is shedding light on the reasons we sometimes like things, or engage in risky behaviour.

We already know that genes decide what we look like, and can predispose us to getting illnesses such as heart disease, cancer, and even attention deficit disorder (though in most cases lifestyle appears to be a more important factor).

But until now relatively little research has been done into how genes affect our behaviour in the shops. A fascinating new academic study suggests that many decisions we have hitherto assumed were down to our free will alone are influenced by our genetic make-up.

Whether we like chocolate and how reckless we are may all have a significant heritable element, according to the authors Itamar Simonson, of Stanford University and Aner Sala, of Florida University, in the US. They reviewed existing scientific papers on genes and personality and also tested 360 twins. Of these, there were 110 pairs of monoxygotic (identical) twins and 60 pairs of dizygotic (non-identical) twins.

By using twins, who share the same family background, the researchers hoped to screen out the impact of 'nurture' while identifying the "nature" influencing genetically identical twins but missing from genetically dissimilar twins.

What they found was strong evidence that "prudence" – an individual's balance of risk and caution – is strongly heritable. When presented with a "vice or virtue" choice, having chocolate (pleasurable) or batteries (useful), identical twins were much more likely to share their twin's choice of utilitarian/non-utilitarian options. Similar but less strong similarities were noticed in another "vice or virtue" test, whether to buy groceries (boring but useful) or have a massage (enjoyable but less useful).

Strong genetic responses were also identified in tests on risk-taking behaviour and delayed gratification.

The study, published in the Journal of Consumer Research, went further than these personality tests and ascertained both types of twins' liking for a wide range of consumer products. Genes seem to play a particularly important role in influencing an individual preference for mustard, dark chocolate, hybrid cars, opera and science fiction. Less strong genetic similarities were detected for milk chocolate and jazz.

Conversely, there seems to be no genetic influence on our liking for many other products and activities: abstract art, body-piercing, tattoos, heavy metal, roller-coasters, coriander, coffee, tomato ketchup, liquorice, iPhones, and even Facebook. We like those purely because we like them.

The authors speculated that in future businesses may be able to market certain products, such as chocolate, at specific members of the public whose genetic information is available, perhaps through voluntary genetic testing. Perhaps in the 22nd century, instead of the police identifying criminals before they do anything wrong – the far-fetched plot of the Tom Cruise film Minority Report – corporations may be able to identify customers before they buy anything.

A more prosaic way of looking at the research is to consider that if you're in debt, hanker for 70 per cent cocoa chocolate, or adore Bizet, you may merely be following a secret dance programmed for you at birth. The authors write of prudence: "Some people may be born with a tendency to be 'in the mainstream' whereas others tend to 'live on the edge'."

"My genes made me splurge on credit cards" – now that's an excuse the bank manager may not have heard before ...

Heroes and villains: Co-op wins readers' voteon animal welfare

Hero: The Co-op

This week the grocery chain won the People's Choice award at the RSPCA Good Business awards in London. Among its achievements, the Co-op sells only Freedom Food, free range or organic eggs, and its own-brand beef comes from cattle reared outdoors. Almost 15,000 voted in the award, sponsored by The Independent. Thank you.

Villian: Daily Express

The Express keeps running dodgy readers' offers. This week the Advertising Standards Authority banned its £20.70 "buy one get one free" offer for an "Alpine Army" watch. It turned out the watch normally costs £9.95 plus post and packing. The Express blamed a production error. Funny how often things seem to go wrong there.

m.hickman@independent.co.uk