Who are the skilled therapists? Associations between personal characteristics and interpersonal skills of future psychotherapists

Objective Facilitative interpersonal skills (FIS) are a promising variable to explain the so-called therapist effect. We aimed to investigate associations between observer-rated interpersonal skills and self-reported personal characteristics of future therapists. Method In this cross-sectional observational study, psychology students and trainee therapists completed self-report personality and sociodemographic questionnaires as well as the FIS Performance Task (German version, observer-rated). Mixed multilevel model analysis was conducted with FIS total mean score (mean value of 312 individual ratings [13 video-clips, 8 FIS-items, 3 raters]) as dependent variable, therapist ID and FIS clip ID as random effects and 15 therapist variables as fixed effects. Results In the present sample consisting of 177 participants (age: M= 29.8 years (SD = 7.3), [18,59]; 79.1% female, 20.9% male) greater therapists' experience level, male gender and lower levels of alexithymia were predictive for higher FIS score when statistically controlling for other therapist variables in the model. Age, self-reported childhood maltreatment, attachment style, emotion regulation and self-concept variables turned out to be unrelated. Conclusion The results can inform psychotherapy training programs. They specifically support the importance of addressing therapists' potential difficulties in recognizing and verbalizing emotions. This is in line with theoretical literature on alliance ruptures and premises of the Alliance-focused training.