Abstract: The relationship between socioeconomic status (SES) and belief in a just world (BJW) has long been contested, with two competing theoretical frameworks offering opposing predictions. The just-world hypothesis suggests that disadvantaged groups develop stronger BJW as a palliative coping mechanism, whereas the just-capital perspective posits that privileged positions afford greater exposure to fair and predictable outcomes, thereby fostering stronger BJW. Existing empirical evidence remains fragmented and contradictory, leaving the direction, magnitude, and boundary conditions of this association unresolved. The present study addresses these controversies through a comprehensive three-level meta-analysis that simultaneously tests these competing hypotheses and systematically maps the moderating architecture underlying the SES-BJW link.
We synthesized data from 58 independent studies comprising 106,585 participants and 113 effect sizes—the largest and most diverse evidence base on this topic to date. Crucially, we adopted a three-level meta-analytic model that explicitly accounts for non-independence among multiple effect sizes nested within the same study, a statistical refinement that yields more accurate standard errors and reduces false-positive rates compared to conventional meta-analytic approaches that either ignore dependency or adopt overly conservative corrections.
Our primary finding reveals a small but statistically significant positive association between SES and BJW (r = 0.12, p < 0.001), unambiguously favoring the just-capital framework over the compensatory just-world hypothesis across the full dataset. This overall effect, however, obscures substantial heterogeneity that is systematically explained by three classes of moderators operating at macro-structural, measurement, and conceptual levels—a tripartite moderation framework that constitutes the principal theoretical contribution of this work.
At the macro-structural level, we identified national income inequality, operationalized by the Gini coefficient, as a powerful contextual moderator. The positive SES-BJW association progressively weakened as inequality intensified and, notably, reversed in direction under highly unequal conditions (e.g., Gini > 0.45). This crossover pattern demonstrates that macroeconomic environments do not merely attenuate or amplify the relationship but fundamentally alter its valence—a finding that reconciles prior contradictory reports by showing that both theoretical predictions are conditionally valid depending on the broader distributive context. In egalitarian societies, the just-capital logic prevails, whereas in severely stratified contexts, the compensatory mechanism hypothesized by just-world theory surfaces among lower-SES groups. To our knowledge, this is the first meta-analytic evidence documenting a regime-switching effect of inequality on the SES-BJW association.
At the measurement level, we found that the association was significantly stronger for subjective SES (assessed via perceived social standing) than for objective SES (indexed by income, education, or occupation). This divergence implies that individuals' phenomenological experience of their social position exerts greater psychological weight than objective resource possession in shaping justice beliefs, suggesting that interventions targeting status perception may be more efficacious than those attempting to alter structural indicators in the short term.
At the conceptual level, SES demonstrated a markedly stronger relationship with personal BJW (beliefs about justice toward oneself) than with general BJW (beliefs about justice in the broader world). This dimension-specific effect indicates that justice beliefs are not monolithic but are differentially anchored to self-relevant versus societal-level experiences, with personal BJW being more directly calibrated to one's own socioeconomic trajectory and thus more sensitive to SES variations.
Collectively, these moderating patterns advance a contextualized understanding of BJW that transcends the static dispositional view prevalent in earlier research. BJW emerges not as a stable personality trait but as a dynamically constructed belief system shaped by the interplay of structural opportunities, perceived social standing, and the referential scope of justice judgments. Importantly, the three-level meta-analytic framework we employed enables simultaneous estimation of within-study, between-study, and sampling variance components, providing more precise moderator tests and more reliable heterogeneity quantification than two-level alternatives.
Theoretically, our findings integrate competing accounts by specifying their respective domains of applicability, thereby moving beyond the either/or debate toward a conditional model of justice belief formation. Practically, the results carry clear policy implications: reducing macroeconomic inequality through institutional mechanisms—such as expanding legal aid accessibility, transparentizing educational and employment selection procedures, and ensuring procedural fairness in public service delivery—can narrow the "just-capital gap" between SES strata by enabling lower-SES individuals to accumulate positive experiences of institutional responsiveness. Furthermore, when structural change is not immediately feasible, framing public messaging to enhance perceived personal justice (rather than abstract general justice) may more effectively sustain BJW among disadvantaged populations, thereby preserving the adaptive functions of BJW for psychological well-being and social cohesion.
We acknowledge certain limitations, including the predominance of cross-sectional designs precluding causal inferences, the geographic concentration of samples in Western and East Asian contexts, and the absence of longitudinal data to examine temporal dynamics. Future research should prioritize experimental and panel studies to establish causality and track within-individual changes in BJW as a function of shifting socioeconomic conditions. Despite these constraints, this meta-analysis provides the most comprehensive empirical synthesis to date, establishing SES as a robust albeit conditional predictor of BJW and charting a nuanced agenda for theory development and policy design in justice motivation research.

Key words: socioeconomic status, belief in a just world, three-level meta-analysis