Is this why you take fewer risks as you get older?

THE young are notoriously impulsive — and with age we become much more risk averse. But don’t flatter yourself that it’s because you’ve become wise over the years. Rather, say researchers at University College London, it’s naturally falling levels of a brain chemical called dopamine that save you from throwing caution to the wind.

As we age, we get less of a thrill from taking risk — so we don’t bother.

Dopamine is one of more than 100 neurotransmitters, chemical messengers that carry signals from the brain to cells in the body. These signals regulate everything from our mood to the speed at which our heart beats.

Dopamine also helps the brain to identify actions that can lead to rewards. Before and after all kinds of pleasurable activities, from eating and drinking to having sex and listening to music, levels of the hormone increase and are ‘felt’ by the brain as pleasure.

Dopamine also plays a key part in addiction, from drug-taking to gambling. The brain learns to identify dopamine-generating activities, causing us to seek them out.

But as we grow older, the amount of dopamine in the brain declines, by up to 10 per cent a year from early adulthood onwards.

This steady loss of the hormone has been linked to a range of conditions associated with ageing, including weight gain, increased tiredness and reduced sex drive.

Now an experiment involving 25,000 people playing games on a specially designed smartphone app shows that declining dopamine may also be the reason why those of a certain age shy away from risky gambles.

It’s well known that most people take fewer risks as they grow older. There are exceptions, of course — think Yuichiro Miura, the Japanese adventurer who defied heart problems to conquer Everest at 70, 75 and, in 2013, 80 years of age.

Until now, it’s been widely thought that the reason we become more risk averse is because we become wiser with age.

With responsibility for families and mortgages, we have more to lose. Not only that, injuries such as fractured limbs will heal less easily and have potentially more serious complications as we grow older.

But the large UCL experiment has shown for the first time that older people don’t automatically shy away from all types of risk.

The surprising conclusion is that they will largely avoid the risks that promise the largest rewards because they are simply not attracted to them — but not those that threaten the greatest loss.

‘A lot of the results from this app show risk aversion and risk seeking are very much in line with what economists have found in other studies,’ says Dr Robb Rutledge, of the Centre for Computational Psychiatry and Ageing Research at University College London (UCL).

‘But we have also found this other component to how people make decisions, and it’s this particular attraction to potential rewards that is affected by dopamine.’

The research comes from The Great Brain Experiment, a smartphone app developed by scientists at the Wellcome Trust Centre for Neuroimaging at UCL.

It allows researchers to gather large amounts of information that previously could be gleaned only in lab experiments.

More than 25,000 people who downloaded the app played a game that involved a series of gambles for points.

The anonymised results were fed back to UCL. Researchers found that players of all ages were equally likely to take risky gambles in an effort to avoid losing points, but 18 to 24-year-olds were more likely than players aged 60 to 69 to take a risk in order to win more points.

However, while a decline in dopamine can lead to caution, excess amounts can have the opposite effect.

ACCoRDING to a paper published in the journal Neurology in 2010, out-ofcontrol gambling and other compulsive activities are side-effects for a small number of patients with Parkinson’s disease whose condition is treated with dopamine (which also plays a role in regulating movement in the body).

The study of 3,000 patients in the U.S. found 13 per cent were suffering from a range of impulse-control disorders, including compulsive spending, gambling, binge-eating and compulsive sexual behaviour. ‘Dopamine has a lot of positive effects for people with Parkinson’s disease,’ says Dr Rutledge.

‘But it can also have these sideeffects because of the other things that dopamine is involved in, including how we make decisions involving risk.’

The authors of the UCL study, published in the journal Current Biology, say their findings offer potential explanation for why ‘negative messaging helps to persuade older people, while a more optimistic approach emphasising large potential rewards might appeal more to younger people’.

They say that has major implications for everyone from companies and governments trying to sell pension provisions to political groups relying on fear tactics to win votes — and, at an outside chance, for bookies laying odds against an Elvis comeback.