Non verbal synchrony in psychotherapy: a review

Interactional synchrony plays a central role in building rapport between individuals, co- regulating emotional states, improving social learning, and predicting the responses of others in social interactions. There is evidence of synchronization in bodily movement, voice, language, and physiology during psychotherapy and that these modalities are related to treatment outcomes, relationship quality, and empathy. The aim of this dissertation is to delve into the topic of nonverbal communication and to highlight how it is central to every psychotherapy session. Specifically, the purpose of this work is to provide an overview of the role of nonverbal behavior in patient- therapist interaction, as well as an understanding of the role of nonverbal synchrony in the context of psychotherapy. A systematic literature review was conducted, to select the most relevant articles concerning nonverbal synchrony in psychotherapeutic interactions. Of particular interest were studies investigating synchrony between patients and therapists conducted in different modalities (e.g., movement coordination, physiological measures, and linguistic coordination). In particular, three studies have been thoroughly analyzed to highlight how nonverbal synchrony can be beneficial for the patient-therapist relationship. Results showed that, in the context of psychotherapy dyads, stronger synchronization is often associated with fewer symptoms and thus, better treatment success. On the other hand, the results of the studies on the analyses of the association between nonverbal synchrony and therapeutic alliance were heterogeneous. In conclusion, the role of nonverbal behavior is of great relevance for the understanding of mechanisms of interactional synchrony in psychotherapy, as well as treatment success.