Nonverbal Synchrony of Facial Movements and Expressions Predict Therapeutic Alliance During a Structured Psychotherapeutic Interview

Nonverbal synchrony (NVS) of a patient’s and therapist’s body parts during a therapy session has been linked with therapeutic alliance. However, the link between NVS of face parts with therapeutic alliance remains unclear. The clarification of this link is important in understanding NVS. Accordingly, we used a video imaging technique to provide quantitative evidence of this link. The 55 participants in this study were the same as in a previous study. Both the participants' and the therapist's faces were video recorded during structured psychotherapeutic interviews. Our machine quantified 500,500 participants’ faces and 500,500 therapists’ faces from the perspectives of facial movements and expressions. Results show that absolute synchrony of happy and scared expressions were positively related to therapeutic alliance. However, symmetrical synchrony of left eye movements negatively predicted therapeutic alliance, although participants’ sex, age, volume of facial movements, and volume of facial expressions were controlled. Absolute synchrony of facial expressions was regarded as emotional interaction within 2 seconds delay, whereas symmetrical synchrony of left eye movements was regarded as a blocker of emotional interaction.

This is a post-peer-review, pre-copyedit version of an article published in Journal of Nonverbal Behavior. The final authenticated version is available online at: https://doi.org/10.1007/s10919-019-00319-w.