Who Am I? A Second-Order Meta-Analytic Review of Correlates of the Self in Childhood and Adolescence.

People's subjective beliefs about themselves affect what people think and, consequently, what they do. Positive self-beliefs are important for many life outcomes, from academic success to well-being, especially during K–12 education as a crucial developmental period. Many empirical studies and meta-analyses have examined correlates of self-beliefs. The present second-order meta-analytic review integrates this large and diverse body of research, addressing two research aims: First, we examined the comparative strength of different variables related to self-beliefs. Second, we provide a methodological review of meta-analyses in this area, thereby facilitating readers' ability to assess the risk of bias when interpreting the results. We summarized 105 first-order meta-analyses published before July 2023 that investigated variables associated with self-beliefs during K–12 education, comprising 493 first-order effect sizes based on more than 8,500 primary studies and more than 16 million children and adolescents. We computed second-order standardized mean differences (SMD) using two-level meta-analyses with robust variance estimation. Personal characteristics (SMD = 0.50) showed stronger relations with self-beliefs than interventions (SMD = 0.27). Achievement (SMD = 0.66) and noncognitive variables (SMD = 0.67) were the personal characteristics most strongly related to self-beliefs compared to cognitive abilities (SMD = 0.30) and background variables (SMD = 0.21). Interventions targeting individual characteristics (SMD = 0.35) and especially self-beliefs (SMD = 0.52) showed larger effect sizes than interventions that focused on improving teaching and classroom structure (SMD = 0.20). Few meta-analyses investigated situational aspects, such as the geographical origin of the sample, in association with children's and adolescents' self-beliefs. Overall, this second-order meta-analytic review provides a comprehensive map of correlates of the self, highlighting pathways for future research. Public Significance Statement: Positive self-beliefs in children and adolescents are crucial for their personal and social well-being, as well as their academic success. This comprehensive review maps out the meta-analytic literature on the correlates of self-beliefs in childhood and adolescence, summarizing which personal characteristics relate to the development of positive self-beliefs during these formative years. The review also highlights the comparative strength of various interventions. Our findings reveal that school achievement and noncognitive psychological variables, such as emotions, motivations, and perceived social support, are strongly related to positive self-beliefs. Interventions that directly target self-beliefs are more effective than those that focus on classroom structures or teaching methods for supporting positive self-beliefs. These insights address the core question of "Who am I?" that every individual asks themselves during the critical phases of childhood and adolescence and support a deeper understanding of one's self-view. For those shaping the contexts of children's and adolescents' lives, these findings point to the most effective strategies for fostering positive self-beliefs, which can lead to healthier, happier, and more successful young individuals. [ABSTRACT FROM AUTHOR]