Why is it that older people seem to have more trouble making decisions? New research suggests that dementia and cognitive decline are not the only reasons, as with age comes trouble evaluating risk and making rational choices, Time magazine reports.

In the latest study on the subject, published in the Proceedings of the National Academy of Sciences, 135 people ranging from ages 12 to 90 were asked to make 320 decisions under a variety of scenarios with different levels of risk involving monetary gains and losses.

Participants over the age of 65 were more likely to be inconsistent in making their decisions, even when there was only one possible and obviously correct answer to a financial problem. For instance, when asked to choose between a definite win of $5 or "a lottery with indefinite odds of winning the same amount," their answers varied much more than their younger peers.

"We found it surprising and stunning," study co-author Ifat Levy, assistant professor of comparative medicine and neurobiology at Yale University, told Time magazine. "These are highly functional older people, and they still got it wrong more often than younger people did." 

All of the older participants were tested for dementia, and all were found to be well, having done fine on multiple cognitive tests. The pressure of choosing an answer quickly was also not a factor either. Why was it that many older participants chose wrong?

Previous studies have revealed that most people are willing to take bigger risks when there's the possibility of gaining money involved, as opposed to when there's a chance of them losing their money. However, for the elderly participants, research revealed it can often be the opposite.

"I think maybe they think that they have less to lose as they are approaching an old age or the end of life," Levy said. "It's definitely a big part of why they may get taken advantage of. At the policy level, this is [maybe] something that should be taken into account in planning retirement and health options that are offered."

Other studies on the impairments in the decisionmaking of the eldery suggest that this factor extends to other facets of life, such as driving, as many older people are unwilling to give up their licenses even if their being on the road poses a risk for others.

"Although this may be a unique study of age and preference on this scale, it is important to recognize that it is in fact a very small study, conducted in two cities in the northeastern United States," the researchers wrote conclusively. "This study should not be taken as offering any final characterization of decision making across the lifespan in the human population."