Family and Peer Stress During Early Adolescence: Phenotypic and Genetic Moderation of Pubertal Development, Sleep and Internalizing Symptomatology

Various physical and psychological forms of development take place during the transition from childhood to adolescence, including the onset of puberty, delayed sleep-wake behavior patterns, and increases in internalizing symptomatology. Theory suggests that pubertal processes influence the onset of internalizing symptoms, and this association may differ between boys and girls. The contextual amplification hypothesis suggests that pubertal development interacts with contextual or dispositional factors to impact risk for psychopathology. Family stress and peer stress are two critical factors during early adolescence that have potential moderating effects on the association between pubertal development and internalizing symptoms. In line with the biopsychosocial framework, the current study examined various psychosocial (e.g., family stress, peer stress) and biological (e.g., sleep, genetics) factors that may have effects on the puberty-internalizing relation. Participants were a racially/ethnically and socioeconomically diverse sample of twins who were part of an ongoing longitudinal study (N=818 children; Arizona Twin Project; Lemery-Chalfant et al. 2019). The current study examined the association between puberty and internalizing symptoms, with stress (i.e., family, peer) as potential moderators, and sleep indicators (i.e., objective and self-reported sleep) as potential mediators. Behavior genetic analyses explored the moderated heritability of family stress on internalizing symptoms. Findings revealed that greater pubertal development predicted higher internalizing symptoms in boys, but not girls. For girls, peer stress interacted with pubertal development to predict internalizing symptoms, but simple slopes were not significant. Sleep indicators were not significant mediators between pubertal development and internalizing symptoms for boys or girls. Univariate twin models revealed environmental influences on internalizing symptoms, and both genetic and environmental influences on peer stress. Family stress did not significantly moderate the genetic and environmental influences of internalizing symptoms.