Interpersonal coordination in couple therapy: Investigating posture and movement matching and nonverbal synchrony between participants

In the field of psychotherapy, research on the interpersonal coordination of movements, e.g., nonverbal synchrony, is a growing area of interest. It has been related to both therapy outcome and therapeutic alliance in individual psychotherapy; however, research in the context of couple therapy is lacking. In this thesis, the interpersonal coordination of nonverbal behavior was examined in couple therapy using data collected in the Relational Mind research project. The data comprised couple therapy sessions from 12 couples. All sessions included four participants: the spouses and two co-therapists. Interpersonal coordination can be divided into two categories: matching, which occurs when two people implicitly (unconsciously) imitate each other’s postures and movements, and interpersonal synchrony, which refers to the dynamic coupling of two or more signals such as movement energy. Both kinds of interpersonal coordination were studied in this thesis. A new coding scheme was developed in Study I for observing matching between participants in couple therapy. Two categories were found: posture matching and movement matching. The relationship between nonverbal matching patterns and therapeutic alliance was qualitatively inspected in one therapy process. The patterns were found to be complex and varied from one participant to another. Intriguingly, after a session in which the alliance was evaluated as weaker, there was more matching between the co-therapists. The coding scheme was used in a multimodal microanalytic study, Study II, which concentrated on four significant moments of one couple therapy session. The aim was to integrate information from the dialogue, the participants’ sympathetic arousal levels, and nonverbal matching behavior. The study revealed the context dependency and individuality of the embodied reactions; the different modalities told their own stories about the couple therapy situations. The final study was a quantitative study of 29 sessions in which interpersonal synchrony of movements, e.g., nonverbal synchrony, was obtained using a frame-differencing method and a synchrony calculation algorithm. Significant synchrony was found in all sessions. The co-therapists’ synchrony differed from synchrony in other dyads in that it was always in-phase; this probably reflected the co-therapists’ professional role. Body synchrony among all participants was significant in relation to all participants’ alliance evaluations, while head synchrony was significant only to the therapists’ alliance evaluations. Interesting patterns were found in the multiperson context: for the clients, alliance was related to synchrony in opposite-gender dyads, whereas for the therapists, synchrony in same-gender dyads was significant. The results from the three research designs gave a broad picture of the interpersonal coordination of nonverbal behavior in couple therapy and to what it was related. In couple therapy, it could be considered a marker of the therapeutic alliance; however, the patterns were more multifaceted in couple therapy than in individual psychotherapy. Keywords: couple therapy, interpersonal coordination, nonverbal synchrony, posture and movement matching, therapeutic alliance, therapy outcome, multimodality, and embodiment