I Feel You … or Do I? An Investigation of Therapist Presence and Partner Effects Via Physiological Synchrony in Couple Therapy.

This study investigated whether therapists' physiological regulation influences clients' autonomic responses during the first session of couple therapy and whether couples' physiology influences each other's. Drawing on polyvagal, attachment, and interpersonal neurobiology theories, we examined physiological linkages in therapy triads. Thirty-three heterosexual married couples participated in a 50-min session, during which respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), and pre-ejection period (PEP) were recorded from both partners and their therapist. Using dynamic structural equation modeling within an actor-partner interdependence framework, analyses focused on lagged effects across the session's beginning, middle, and end. Results showed clients exhibited strong physiological inertia across all measures, suggesting autonomic rigidity in early therapy. Therapist EDA predicted husbands' EDA early in the session, while wives' EDA predicted husbands' EDA later in the session. No directional effects were found for RSA or PEP. Clinical implications of these subtle therapist and spousal influences on physiological arousal are discussed.