Esther Mertens

112 | Chapter 6 Abstract Many universal school-based interventions aim to stimulate students’ intrapersonal (e.g., self-esteem) and interpersonal (e.g., school climate) domains. To improve our understanding of why some of these interventions yield stronger effects than others, we identified intervention components that are related to stronger or weaker intervention effects. We systematically searched four databases (i.e., PsycINFO, PubMed, ERIC, CENTRAL) for controlled evaluations of universal school-based interventions. In total, 104 included studies (529 effect sizes) reported on 99 unique interventions. Interventions showed small positive effects in the intrapersonal ( d = .19) and interpersonal ( d = .15) domains. Focusing on self-awareness and problem solving, using more active learning approaches, and using more extensive interventions predicted stronger intervention effects on aspects of both domains. In contrast, efforts to improve emotion regulation, assertiveness, cognitive coping, and using group discussions predicted weaker intervention effects. Our finding that commonly implemented components did not necessarily predict stronger intervention effects suggests the need to carefully select components for inclusion in interventions. PROSPERO registration number: CRD42019137981 Keywords: Components, School-based intervention, Intrapersonal domain, Interpersonal domain, Students