PROJECT SUMMARY – PROJECT 2 Social connectedness and inclusion are essential for well-being and health, particularly during adolescence, a period characterized by an increased salience placed on peer relationships and experiences. Technology and digital media (TDM), particularly social media, has the affordance of connecting with peers. In fact, TDM has become an increasingly important form of communication for adolescents, 71% of adolescents report using more than one social media site and 92% of adolescents between the ages of 13-17 years old report going online daily. Reviews on TDM use, however, suggest that there is not consensus on the impact of TDM and social media use on well-being and health behaviors among adolescents, finding positive, negative, and null results. They highlight that little evidence exists that examines potential moderating factors between TDM use and well- being and health outcomes, which limits our understanding of what influences outcomes of interest. Thus, there is an urgent need to fill this gap. Effects associated with TDM use may depend on specific ways that adolescents use TDM. For example, if high levels of exposure to certain kinds of TDM, such as social media, sensitize adolescents to other people’s opinions, they may be more reactive to negative experiences such as social exclusion, but may benefit more from experiences of social inclusion. This sensitivity may help explain the mixed findings within the literature. The current study proposes to test this idea by measuring adolescent’s exposure to social media (drawing data from Projects 1 and 3) that have the affordances of social connectedness (i.e., likes, comments, number of friends or followers). Then we will relate these experiences longitudinally to their reactivity to experiences of social inclusion and exclusion to predict health and risk behaviors as well as well-being (drawing data from Projects 1 and 3) and examine how changes in functional reactivity across the social transition period from middle to high school, a period associated with changes in social ties, risk-taking, and challenges to well-being, may influence these relationships. This data will not only examine deficits associated with social media use that lead to poorer well-being and unhealthy behaviors, but will also examine the strengths of social media use and how they relate to better well-being and healthy behaviors. Further, if adolescents are sensitized to social cues, the data can help identify ways to help steer adolescents towards social media engagement that leads to greater well-being and healthier behaviors. This project aligns with the current RFA as it tests how TDM usage affects health behavior. This project specifically aligns with two areas of interest for this RFA: 1) interdisciplinary studies of TDM usage across adolescence employing multi-level assessments of neurodevelopment to examine interrelated developmental changes in brain function and complex behavior, and ...