Jealousy Links Comparisons with Siblings to Adjustment among Emerging Adults

Objective To explore the correlates and implications of sibling jealousy during emerging adulthood. Background Rooted in research and theory on parental differential treatment (PDT) and social comparisons, we expected that more frequent social comparisons between siblings—specifically, PDT as well as upward comparisons (“my sibling is better off than I am”) and downward comparisons (“I am better off than my sibling”)—are positively linked to sibling jealousy, which, in turn, is positively related individual and relational maladjustment. Method Participants included 454 young adults (M = 22.44, SD = 1.50 years of age) who participated in Internet‐based surveys recruited via Amazon Mechanical Turk. Results Social comparisons between siblings generally predicted feelings of sibling jealousy, which, in turn, were positively related to young adults' depressive symptoms and sibling conflict. Although PDT was salient in the lives of these emerging adults, siblings' other social comparisons were more strongly linked to their internalizing symptoms and sibling relationship qualities. Conclusion These findings fill a gap in knowledge about the nature and implications of sibling relationships during emerging adulthood and clarify the links between young adults' cognitions (PDT, social comparisons), affective states (jealousy), and behaviors (depressive symptoms, sibling relationship qualities). Implications Sibling relationships should be reflected on more broadly across the life course because family and sibling processes permeate the lives of individuals well after moving away from their family of origin. In particular, it is important for those who work with young adults, including practitioners, to consider the implications sibling relationships have for individual and relational adjustment during emerging adulthood. This includes focusing on mitigating the negative implications of sibling comparisons and sibling jealousy, which continue into emerging adulthood, and ultimately may enhance young adults' emotional and behavioral well‐being.