Esther Mertens

28 | Chapter 2 Besides the student characteristics, we will also study trainer characteristics: Gender, ethnicity, education level, level of self-perceived competence, expertise, and degree of training and supervision. Findings concerning characteristics of professional therapists are inconsistent. Whereas some studies have found significant impact of (one of) these characteristics on treatment outcome (e.g., Anderson, Ogles, Patterson, Lambert, & Vermeersch, 2009; Bryan, Dersch, Shumway, & Arrendondo, 2004; Wheeler, & Richards, 2007), other studies have found no relation (e.g., Huppert et al., 2001; Wampold & Brown, 2005). Characteristics of (non-professional) therapists are often neglected in intervention studies. By studying trainer characteristics of non-professional therapists as moderators we will clarify the role of these characteristics on the effectiveness of R&W. We hypothesize that R&W is more effective when trainers are males, have a Western ethnic background, have a higher education level, have more self-perceived competence, have more expertise, and received more training and supervision. Additionally, we will analyze parental characteristics as moderators: Parental sense of parenting competence and positive parenting (i.e., parental warmth andmonitoring). Parents with a high sense of competence feel capable and adequate in interactions with their child (Deković et al., 2010). It might be that due to this confidence parents are more susceptible for information about the strategies and ‘language’ of R&W and apply these at home. Positive parenting enhances adolescents’ social competence (Taylor, Conger, Robins, & Widaman, 2015) and the parent-child relationship (Pinquart, 2013). It might be that these adolescents feel more competent to incorporate R&W into their daily lives and tell their parents about R&W within that close and trusting relationship. Parents learn more about this intervention which enables them to also apply R&W. Therefore, we hypothesize that R&W is more effective for students with parents with high levels of parental sense of competence and positive parenting. The third aim is to study the working mechanisms of R&W. Self-control, self- reflection, and self-esteem will be examined as mediators of the effect of R&W on students’ socio-emotional adjustment and social safety. Self-control, self-reflection, and self-esteem are theorized as the three pillars through which R&W aims to establish the desired developments (Ykema, 2002). Additionally, emotion regulation will be examined as mediator. According to the theory behind R&W, students will become better aware of the physical representations of their emotions, for instance muscle tensions and a-rhythmic breathing. Raising students’ emotional awareness is expected to facilitate them to perceive their emotions and regulate them. This improvement in emotion regulation would lead to an increase in their socio-emotional adjustment and social safety (Ykema, 2002). Analyzing these mediators enables us to test the theory of R&W. We hypothesize that R&W will increase students’ self-control, self-reflection, self-esteem, and emotion regulation which, in turn, will enhance their socio-emotional adjustment and social safety. Furthermore, deviant and prosocial communication (i.e., verbal and non-verbal) will be analyzed as mediators of the effect of R&W on social safety. Communication is a recurrent theme throughout the intervention. It is proposed in the theory that