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.