Longitudinal Relations between Social Mindfulness and Social Behavior in Early Adolescence: Disentangling Between- and Within-Person Associations.

Despite evidence indicating that social mindfulness may be a precondition for both prosocial and aggressive behavior, there remains a limited understanding of how the bidirectional dynamics between them unfold over time. Framed in the developmental cascade model, this study examined the longitudinal reciprocal relations between social mindfulness and these two distinct social behaviors among early adolescents by disentangling within-person and between-person effects. A total of 1087 Chinese early adolescents (48.7% girls; M = 11.35 ± 0.49 years at Time 1) participated in a three-wave longitudinal study with about four-month assessment intervals. The random-intercept cross-lagged panel model indicated that, at the within-person level, social mindfulness and prosocial behavior positively predicted each other over time. Furthermore, fluctuations in social mindfulness were found to negatively predict changes in aggressive behavior at subsequent time points, but the reverse was not true, suggesting a unidirectional influence. A similar pattern was found between social mindfulness and reactive aggressive behavior, but no significant bidirectional effects emerged between social mindfulness and proactive aggressive behavior. These findings highlight the role of social mindfulness in shaping early adolescents' social behavior over time, thus providing insights for more targeted and effective interventions to foster prosocial behavior and prevent aggressive behavior.