LAUSR

Negative outcome expectations of psychological treatments predict unfavorable treatment outcomes. Therefore, therapists should approach negative outcome expectations and ideally transform them into more positive outcome expectations. In this study, we investigated the therapist’s interpersonal behavior to optimize the modification of negative outcome expectations. After inducing negative expectations in an online experiment, we presented different videos of therapist–patient interactions to violate the induced negative outcome expectations. We kept the expectation-violating information constant and manipulated the therapist’s warmth and competence. Results confirmed a significant influence of the therapist’s warmth and competence on expectation violation, which led to the most positive outcome expectations when the therapist was both warm and competent. In contrast to former correlational analyses, our experimental study confirms the causal role of the therapist’s interpersonal behavior and its impact on changing patients’ negative outcome expectations. On the basis of these findings, more powerful approaches to optimize critical outcome expectations can be developed.