The effects of belief in a just world on third-party punishment: A three-level meta-analysis

Abstract: See injustice and draw your sword against it. Since its proposal, the just world theory has focused on the phenomenon, yet its theoretical hypotheses and empirical findings remain inconsistent. To resolve this controversy and uncover the reasons for the divergent results, we conducted a three-level meta-analysis to systematically examine the effects between belief in a just world and third-party punishment and the moderating variables in the relationship. Through literature search and screening, a total of 46 research papers with 93 effect sizes were included, and the total sample size was 15,772 participants. The main effect analyses revealed a significant but weak positive correlation between belief in a just world and third-party punishment (r = 0.08, 95% CI = [0.03, 0.14]). Moderator analyses indicated that the effect was moderated by the self-other dimension of BJW, the form of third-party punishment behavior (social punishment vs. material punishment), cultural background, the violation scenario and sample type but was not by observers' gender, observers' age group, the explicit−implicit dimension of BJW, the type of third-party punishment (punishment behavior vs. punishment willingness) and research method. These findings contribute to addressing the competing hypotheses of the just world theory and specifying its boundary conditions, offering valuable insights for future theoretical development and empirical research.