Interpersonal neural synchrony as a potential neural bridge between co- and self-regulation: A Narrative Review

The development of self-regulation is a foundational milestone of early childhood, predicting outcomes from future academic success to mental health throughout the lifespan. Accumulating behavioral research suggests that self-regulation is not innate but socially constructed, originating in "co-regulatory" interactions where caregivers modulate a child's arousal and attention. However, the neural mechanisms supporting the transition from external regulation to internal capacity remain poorly understood. This opinion piece proposes that interpersonal neural synchrony (INS), the temporal alignment of brain activity between interacting partners, serves as a critical biomarker of this transition. We synthesize evidence linking INS to both co-regulation and to self-regulation strategies, arguing that INS may serve as the neural bridge that facilitates the transmission of regulatory competence from dyadic to independent regulation. We identify critical research gaps and propose a framework in which INS is no longer understood solely as a marker of interpersonal dependency, but as a dynamic mechanism supporting the development of autonomy.