This longitudinal ecological momentary assessment study examined whether adolescents' use of social media to interact with peers relates to their experiences of social connectedness, social craving, and sensation seeking on an hourly level. Further, we investigated whether these associations differ for adolescents who were nominated by their peers…

This study examines developmental change across adolescence in the similarity of friends versus nonfriends. This differential in similarity is a key aspect of the organization of the peer context of development: The stronger the correlation between friends for an attribute, the more the attribute delineates clustering and divisions of friendships.…

Co-rumination is a dyadic process between relationship partners that refers to excessively discussing problems, rehashing problems, speculating about problems, mutual encouragement of problem talk, and dwelling on negative affect. Although studies have addressed youths' "tendency" to co-ruminate, little is known about the nature of…

The self-equilibrium hypothesis underlines the importance of having a strong core self, which is defined as a high and developmentally stable self-concept. This study tested this hypothesis in relation to body image (BI) trajectories in a sample of 1,006 adolescents (M[subscript age] = 12.6, including 541 males and 465 females) across a 4-year…

This longitudinal study of adolescent girls and boys examined the contributions of social (peer appearance context), psychological (internalized appearance ideals and appearance social comparison), and biological (body mass) factors to the development of body dissatisfaction. Students (165 girls and 139 boys) completed questionnaires when they…