Neurodevelopmental Changes in Parent and Peer Influence on Risky Decision Making across Adolescence

Parents and peers play an important role in the type of risk attitudes and behaviors that adolescents learn, internalize, and act upon, yet little is known about how these various socialization mechanisms interact and inform risky decision making across development. In this dissertation, I present a program of research investigating neurodevelopmental changes in the value, internalization, and socialization of parents’ and peers’ risk attitudes across adolescence. Study 1 shows that, unlike susceptibility to parent influence, susceptibility to peer influence is sensitive to individual differences in the value associated with peers’ risk attitudes during early adolescence, an effect that went away by mid-adolescence. Study 2 suggests that adolescents consider their own risk attitudes and the internalized risk attitudes of their parents—but not their peers—when constructing their own risk attitudes, particularly in early adolescence. Study 3 demonstrates that adolescents largely stand firm in their own attitudes under conflicting influences and conform to parents and peers selectively based on the type of behavior and influence. These studies provide novel evidence for the role of midline cortical brain regions (e.g., ventromedial and medial prefrontal cortices) in integrating others’ risk attitudes across development and across social contexts. Taken together, this dissertation identifies key neurodevelopmental processes in adolescence that can shift the motivational value away from external influences to individual preferences during risky decision making.Doctor of Philosoph