Coregulation patterns in emotional sharing dynamics among adolescent friend dyads.

Adolescence is a critical period characterized by heightened emotional intensity and volatility during which peer friendships gradually replace family as the primary source of emotional support. Understanding patterns of emotional interaction between adolescent friends is crucial for promoting their socioemotional development. Guided by the temporal interpersonal emotion systems theory, the present study focused on emotional coregulation-reciprocal emotional linkage in which mutual damping enables dyads to reach dynamic equilibrium. We employed dyadic discussion tasks (negative problem discussion vs. pleasant topic discussion), combined with second-by-second facial expression coding to capture adolescents' emotional expressions. Emotional dynamics were modeled using the coupled oscillator model, and distinct patterns were identified through latent profile analysis. Associations between these patterns and individual traits as well as relational characteristics were also examined. In the negative context, two profiles emerged: "coregulation," marked by mutual emotional convergence and gradually stabilized over time, and "nonregulation," marked by persistent fluctuation without returning to equilibrium. Friendship duration was positively associated with the likelihood of entering the coregulation pattern, whereas perceived problem severity and affective empathy were negatively associated with this pattern. In the positive context, coregulation did not emerge as a typical pattern. Instead, dyads were differentiated by "in-phase" versus "out-of-phase" oscillation, which were not significantly associated with individual or relational factors. The results provide empirical evidence for understanding the emotional dynamics in adolescent close friendships and may help inform peer-oriented approaches aimed at supporting adolescents' socioemotional well-being. (PsycInfo Database Record (c) 2026 APA, all rights reserved).