Journal of Social and Personal Relationships, Ahead of Print.
Previous research has highlighted the impact of social network partners on individuals’ attitudes and behaviors and the significant role that siblings often play in providing lifelong support, especially in times of important life events. However, a few studies have examined the intragenerational transmission of divorce risks. Given the increasing prevalence of unmarried cohabitation, however, no study has yet unraveled the link between siblings’ relationship breakups in general, and neither has the impact of siblings’ partnership type and demographic characteristics been investigated. This study aims to understand cross-sibling influence on relationship breakup, including both divorce and separation, and whether sibling similarity in partnership type and demographic traits explain the social influence processes. We used longitudinal data from the Belgian population register and family fixed-effects event history analysis. Partnered individuals (N = 67,113) and their siblings were followed between 1998 and 2018. The results revealed that an individual’s likelihood of experiencing a union dissolution was lower following that of a sibling. This was particularly pronounced among siblings belonging to the same partnership type (both married or both cohabiting) and close-in-age siblings. For instance, after a sibling’s separation from a cohabitation, cohabiters were at lower odds of dissolving their union than the married, especially when they had a small age gap. The findings indicate that accounting for the time-constant factors originating from the family context, a sibling’s breakup might have a protective impact on one’s own relationship status and duration. The study contributes to the growing knowledge on intragenerational transmission of partnership dissolution.