Sibling Relationships in Adulthood: Research Findings and New Frontiers

Sibling relationships, the longest‐lasting relationships in most people's lives, have been understudied compared to other family relationships. The goal of this review is to increase understanding of sibling relationships from midlife to older adulthood by integrating aspects of psychological and sociological theories, including social exchange, family systems, and life course perspectives, to better understand the structure, function, processes, and meaning of sibling relationships in middle and later life. This theoretical integration promotes a comprehensive study of sibling relationships by considering individual and family characteristics as well as the broader social and cultural contexts in which sibling ties are situated. Further, this integration facilitates the study of sibling relationships across time. In addition to reviewing current knowledge about sibling relationships in adulthood, we discuss directions for future research, the methodological practices necessary to advance this research, and the translational significance of research on adult sibling relationships for aging populations.