Harms, Madeline2017-10-092017-10-092015-07https://hdl.handle.net/11299/190560University of Minnesota Ph.D. dissertation. July 2015. Major: Child Psychology. Advisor: Kathleen Thomas. 1 computer file (PDF); iv, 132 pages.Adolescence is characterized by a myriad of social, emotional, and cognitive transitions. Most notable are increased risk-taking behavior, thought to result from heightened reward sensitivity, and increased importance of peer relationships, which may be enabled by heightened sensitivity to social information. These factors may converge to increase the risk of anxiety and depression in adolescence. The goal of the current study was to examine risk and reward sensitivity, responses to positive and negative social information, including social ostracism, and symptoms of anxiety in three age groups: children, adolescents, and adults. 158 participants completed a social or nonsocial gambling task, were socially ostracized by peers on the Internet, and then completed the same gambling task to examine changes in risk-taking behavior. Results are discussed in terms of general developmental trends on the social and nonsocial gambling tasks, links between anxiety and risk-taking, and links between emotional sensitivity to ostracism and change in risk-taking in each age group. A number of unique trends were found in the child and/or adolescent age group, including positive correlations between anxiety and risk-taking and sensitivity to ostracism and increased risk-taking. However, adolescents did not show heightened risk-taking or sensitivity to social information in general, relative to children and adults. Findings speak to the importance of testing multiple age groups in studies of adolescent development, and support the notion that interactions between social sensitivity and reward sensitivity may help to explain the risk for internalizing problems in adolescence.enThesis or Dissertation