CAREER: Psychological and Neurodevelopmental Mechanisms of Social Influence on Adolescent Decision-Making

Harvard University, Cambridge MA

Investigators

Abstract

During adolescence, individuals begin to make increasingly independent decisions that involve weighing the potential risks and benefits of their actions. Although the decisions adolescents and adults make are similar in many situations, there are certain contexts that lead to more risky decisions by adolescents. This is the case in social contexts: adolescents (but not adults) tend to make riskier choices in the presence of peers. Although peers' influence on adolescent risk-taking is documented in real-world crime statistics, health statistics, and in controlled laboratory experiments, just how peers uniquely influence adolescents remains poorly understood. The overarching goals of this research are threefold: a) to refine understanding of adolescent risky behavior by demonstrating what aspects of decisions are vulnerable to peer influence, b) to identify how the developing brain contributes to peer influence on adolescent risk taking, and c) to evaluate how laboratory measures of peer influence relate to actual risky behavior in daily life. To carry out this work, dyads of adolescents and dyads of young adults will complete a series of decision making-tasks designed to quantify components of risky choices. For instance, mathematical decomposition analyses can isolate how much risk an individual is willing to tolerate in order to obtain a potential reward. Participants complete these tasks in experimental configurations that vary in their degree of social evaluation. Peers are either absent, present and monitoring the participant's level of riskiness, or present but unable to monitor the participant's level of riskiness. These peer configurations build on recent findings by Leah Somerville and others showing that the mere presence of a peer may be sufficient to evoke riskier choices in adolescents. Comparisons of risky choices in these three contexts will disentangle the sources of peer influence that depend on the peer awareness of risky choices, compared to sources of peer influence that are evoked merely by the presence of a peer. In addition, confidential surveys will measure risk-taking in everyday life. They will be used to bridge the laboratory and the real world through analyses that ask what characteristics of the dyads, and what characteristics of individual's riskiness relate to their laboratory-based choices. Functional magnetic resonance imaging (fMRI) is used to measure how the still-developing brain uniquely processes information about social evaluation, and how these processes interact with decision-making processes. This project stands to build foundational knowledge about how neurodevelopment during adolescence shapes the development of complex social behavior. More broadly, this work can be extended to help predict the particular 'ingredients' of a situation that lead adolescents to take unhealthy risks. Further, this project generates key data to address legal-ethical issues of youth culpability for crimes committed with peers.