Belief in a Just World Promotes Youth Intergenerational Altruism by Increasing Subjective Well‐Being: Authenticity Makes a Difference

Promoting intergenerational altruism among the current youth generation is crucial, and belief in a just world (BJW) may be a protective factor for intergenerational altruism. Inspired by the broaden-and-build theory of positive emotion, our research aims to investigate the relationship between BJW and intergenerational altruism among youths as well as to explore the mediating role of subjective well-being and the moderating role of authenticity in the focal relationship. Three empirical sub-studies with cross-sectional, experimental, and longitudinal designs were performed. Study 1 (N = 3398) employed a set of scales to preliminarily explore the relationships among BJW, subjective well-being, intergenerational altruism, and authenticity. Study 2 (N = 82) used a between-subjects experimental design to further test hypotheses by manipulating BJW. In Study 3 (N = 1365), a three-wave longitudinal survey was conducted to validate the moderated mediation model obtained in Studies 1 and 2. These studies converged to confirm that youths with a high BJW are more inclined to exhibit greater intergenerational altruism due to their enhanced subjective well-being. Notably, this mediation effect-along with the direct effect of subjective well-being on intergenerational altruism-was much stronger among youths with higher levels of authenticity. This work not only corroborates the significance of BJW in facilitating youth intergenerational altruism but also introduces a novel lens through which to enhance such altruistic behaviors by focusing on interventions targeting subjective well-being and authenticity.