MedicalResearch.com: What are the main findings of the study?
Answer: We found that individual risk preferences as well as consistency and rationality in choice change with age. Just like cognitive abilities, the ability to make consistent and rational decisions considerably declines in older adulthood. Tolerance to risk in the domain of gains follows an inverted U-shaped pattern along the life span, with older adults (65+ y. o.) and adolescents being more risk averse than young or midlife adults. Interestingly, in the domain of losses, older adults are willing to accept significantly more risks than adolescents, young and midlife adults.
MedicalResearch.com: Were any of the findings unexpected?
Answer: Yes, definitely. We were stunned by the frequency of inconsistent and irrational choices among the older participants in our study. They were all healthy and had IQ scores significantly above the average. The fact that these highly functioning older adults showed a significant decline in choice consistency and rationality is really worrying and suggests that the problem may be even more serious in general population.
Another thing that surprised us is that older adults, who are usually considered as very cautious, were the most risk-seeking group when the decisions they made considered loss outcomes.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: Both clinicians and patients should be aware that individual preferences for risk as well as the ability to make rational and consistent decisions changes with age. Clinicians should know that older adults are at a higher risk of making erroneous decisions that may adversely impact their health and welfare. It is also important to bear in mind that older adults may be comfortable with different degree of risk in the medical treatments than younger adults. Paying attention to individual preferences and decision-making abilities will ensure that patient’s welfare is maximized.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: There are still a lot of unknowns regarding decision making across the lifespan. For example, we would like to understand what biological changes lead to the increased rate of choice inconsistencies and irrationalities in older adults. Such knowledge would help us design treatments that could counteract these adverse effects. Ideally, we would like to follow a very large sample of people throughout their whole lives to precisely identify when changes in decision-making occur and identify risk factors.
Like cognitive function, decision making across the life span shows profound age-related changes
Agnieszka Tymula, Lior A. Rosenberg Belmaker, Lital Ruderman, Paul W. Glimcher, and Ifat Levy
PNAS 2013 ; published ahead of print September 30, 2013, doi:10.1073/pnas.1309909110