LONDON, June 3 (UPI) -- Many people become less willing to take risks as they age, with or without the chance of gaining a large reward, and researchers think they may have an explanation for why this is.
Declining levels of dopamine in people's brains as they age were linked to less willingness to take risk in a large study involving digital gambling scenarios, researchers at University College London report.
Dopamine levels fall by up to 10 percent with each decade of adult life, which the researchers say matches the steady decline of people's willingness to take bigger risks.
The researchers used a smartphone app to give people an opportunity to choose the type of risk they'd be open to, finding that as the age of participants increased, so did their lack of willingness to take a risk with the potential for a big reward.
Although older people were willing to take a risk to prevent a loss, the potential for a positive outcome was not enough to get them to take a chance, researchers say.
For some people, understanding the amount of risk someone will take means understanding how they think -- with UCL researchers using politics as an example where the negative risk factor has a far greater effect on people's thought processes than a positive one.
"Political campaigners often frame voting decisions negatively, for example saying that UK households would be $6,200 worse off if the UK decides later this month to leave the EU rather than $6,200 better off if the UK decides to remain part of the EU," Dr. Robb Rutledge, a researcher at the Institute of Neurology at University College London, said in a press release. "They already know that negative messaging helps to persuade older people, whereas a more optimistic approach that emphasizes large potential rewards might appeal more to younger people who are less likely to vote. Our new findings offer a potential neuroscientific explanation, suggesting that a natural decline in dopamine with age might make people less receptive to the positive approach than they would have been when they were younger."
For the study, published in the journal Current Biology, researchers recruited 25,189 participants between the ages of 18 and 69 to play a smartphone app called The Great Brain Experiment.
Players started with 500 points and aimed to win as many as possible in 30 rounds of the game, each of which was different. In "gain" trials, players were given a choice between a safe option of guaranteed points or a risky 50-50 chance to win more points or gain nothing. In "loss" trials, players could choose to lose a guaranteed number of points, or risk a 50-50 chance to lose more points or lose nothing. Other rounds contained a risk for both -- with participants choosing between a safe option of zero points or a gamble to either gain or lose points.
Overall, 56 percent of participants chose to gamble in rounds where they could potentially lose, and 67 percent gambled in trials where they could win or lose. In rounds where the gamble was to gain, 72 percent of 18- to 24-year-old participants gambled while 64 percent of those in the 60- to 69-year-old group took the chance.
"As we age, our dopamine levels naturally decline which could explain why we are less likely to seek rewards," Rutledge said. "The effects we saw in the experiment may be due to dopamine decline, since age was associated with only one type of risk taking and mirrored the known effects of dopamine drugs on decision making. Older people were not more risk-averse overall, and they didn't make more mistakes than young people did. Older people were simply less attracted to big rewards and this made them less willing to take risks to try to get them."
