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.…

During adolescence, gender identity (GI) develops through a dialectic process of personal reflection and with input from the social environment. Peers play an important role in the socialization of gendered behavior, but no studies to-date have assessed peer influences on GI. Thus, the goal of the present study was to examine peer influences on…

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…

Social goals are associated with behaviors and adjustment among peers. However, it remains unclear whether goals predict adolescent social development. We examined prospective associations among goals, physical and relational aggression, social preference, and popularity during middle school (N = 384 participants, ages 12-14 years). Agentic…

Prospective longitudinal data from over 14,000 youth residing in 28 communities in the rural United States were analyzed to examine the emergence of mixed-sex friendship groups in early adolescence. Youth were surveyed on 5 occasions between fall of 6th grade and spring of 9th grade. At each assessment, youth reported the names of up to 7…

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…