The Role of Learning in Age-Related Differences in Decision Making under Uncertainty

The global population is growing older. In addition to this demographic change, individuals are increasingly being asked to take personal responsibility for their own economic welfare. The confluence of these trends can have profound economic consequences that underscore the importance of understanding decision making in older adults. While the study of decision making and aging has grown in recent years, there have been two important limitations in this work to date. First, researchers often assume that when people make decisions, they calculate the expected value of each option by multiplying the value of each by the probability that it will occur. This overlooks the possibility that people may focus more on value or probability when making decisions. Second, despite the fact that age differences in decision-making have been linked to learning deficits, interpretations in the literature often ignore the influence these deficits have on decisions. To address these limitations, this dissertation focused on the ability of older adults to learn probabilistic relationships, and how this learning influences decision-making behavior. The first study examined learning of stable, or consistent, probabilistic relationships in healthy and young adults. The study revealed age differences in learning, suggesting that young and older adults may use different cognitive systems when learning stable probabilistic relationships. The second study built upon the first by examining age differences in learning both stable and volatile, or unstable, probabilistic relationships. This study revealed that individual differences in learning predict decision-making performance. Specifically, learning stable relationships predicted performance on a stable decision making task while learning volatile relationships predicted performance on a volatile decision making task. Importantly, the converse relationships were not significant, revealing a dissociation between learning of stable and volatile relationships. Collectively, these results support the hypothesis that age-related deficits in learning underlie age differences in decision making and highlight the need to further characterize how learning and decision making interact with the aging process.Degree awarded: Ph.D. Psychology. The Catholic University of Americ