“…More direct support for the role of competences in psychopathology development comes from results of preventive intervention studies showing that reductions in levels of psychopathology were partially accounted for by improvements in peer relations, such as improved peer acceptance, reduced peer victimization, and reduced affiliation with deviant friends (Bierman et al, 2002; van Lier & Crijnen, 2005; Vitaro, Brendgen, Pagani, Tremblay, & McDuff, 1999; Vuijk, van Lier, Crijnen, & Huizink, 2007; Witvliet, van Lier, Cuijpers, & Koot, 2009). Similarly, in several studies iatrogenic, or unwanted negative effects of intervention were explained by negative peer influences on initially nonaggressive children (Dishion & Dodge, 2005; Dishion, McCord, & Poulin, 1999; Dishion, Poulin, & Burraston, 2001; van Lier, Vitaro, & Eisner, 2007). Other recognition for the entanglement of psychopathology and competences comes from developmental psychopathology, positive psychology, and resilience theory (for an overview, see Masten et al, 2006).…”