Interpersonal Synchrony

Interpersonal synchrony is the coordination in time of behavior or physiological activity between people during interaction. It describes how their activity aligns, rather than simply whether they perform similar actions. Researchers study it in movements, vocal behavior, and bodily processes, with the precise meaning depending on which activity is being measured .¹

Synchrony does not require identical movements. One person's head nods can be coordinated with another person's hand gestures. The important feature is their timing relationship. This distinguishes synchrony from mimicry, which concerns resemblance between behaviors and need not involve close coordination in time. Two people can therefore show synchrony while making different movements, or imitate each other without closely synchronizing .²

Synchrony can be intentional, as when people deliberately coordinate their movements, or emerge spontaneously while they interact. It can involve repeated rhythms or less regularly timed activity, and one person may lead while another follows. These differences are why synchrony is best understood as a family of timing relationships rather than a single all-or-nothing state. Describing it clearly requires specifying what is coordinated and how that coordination unfolds over time .¹