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. (PsycInfo Database Record (c) 2024 APA, all rights reserved).