Different peers influence different behaviors: Conformity to best friends and status-based norms across the transition into adolescence

Friends and popular peers are important sources of influence across the transition into adolescence. The present study examines the assertion that the magnitude of influence from friends and popularity-based norms varies across behavioral domains. Participants were 543 (268 girls, 275 boys) students from 29 5^th-8^th grade (ages 10 to 14) classrooms in three Lithuanian public middle schools. Most were ethnic Lithuanians. Self-reports of socioemotional adjustment, including emotional problems, lack of emotional clarity, problem behaviors, social media use, and weight concerns, were collected in the fall and winter of a single academic year, approximately three months apart. Popularity and academic achievement were assessed through peer nominations. Top-ranked best friends were identified from outgoing nominations. Status-based norms, calculated separately for each socioemotional adjustment variable in the fall (Time 1), represented popularity-weighted classroom averages. Results from longitudinal Group Actor-Partner Interdependence Model analyses indicated that best friends and status-based norms exerted differing amounts of influence over different behaviors. When both were included in the same model (with shared effects removed), best friends influenced emotional problems, lack of emotional clarity, and problem behaviors. Among older adolescents, best friends also influenced academic achievement. Status-based norms influenced social media use and, among older adolescents, weight concerns.