Sydney, Dec 15 (IANS): Older adults are less inclined to take risks, like participating in a lottery, but this may be linked to changes in brain anatomy rather than age, a study has found.

It showed that risk aversion is better explained by changes in grey matter volume in an area in the brain's right posterior parietal cortex, rather than by age itself.

"We know that as people age, they tend to become more averse to taking risks," said Agnieszka Tymula from University of Sydney in Australia.

"Our research suggests the speed at which our brain's structure changes has a greater impact on our tolerance of risk than chronological age," Tymula added.

For the study, the research team presented a series of choices to 52 study participants, aged 18 to 88 years. Participants could either receive $5 or take their chances with a lottery of varying amounts and probabilities.

For example, a participant could choose the certain gain of $5 or opt for a 25 per cent chance of getting $20. Participants were each assigned a number denoting their level of risk tolerance based on their choices.

After analysing the risk choices and MRI measurements, the researchers confirmed that age-related decline in risk tolerance correlates more with changes in brain anatomy than with age. Older participants preferred the guaranteed option, compared to younger participants.

"We found that if we use both the gray matter volume and age together as predictors of risk attitudes, the gray matter volume is significant, while age is not," explained Ifat Levy, associate professor at Yale University in Connecticut, US.

"This means that gray matter volume accounts for age-related changes in risk attitude more than age itself," Levy said.

The finding provides new insight into neurological factors that affect risk preferences and decision making among older adults. It may also lead to strategies for modifying decision making.

The study was published in the journal Nature Communications.