A Developmental Approach to Sibling Relationships: Disaggregating the Components of Sibling Relationship Quality over Time for Siblings of Individuals with Intellectual Disability

Siblings can serve as significant companions and caregivers for individuals with ID throughout the lifespan. Yet, the developmental course of sibling relationships for siblings of individuals with ID has not been well addressed in the current literature. Thus, the current study examined change over time in four dimensions of relationship quality (power, intimacy, conflict, and rivalry) as well as how the constellation variables of sex, birth order, and age differences affected the development of relationship quality. Sibling relationships were found to have a stable power structure, with the nondisabled sibling reporting higher levels of power in the relationship. Developmental trajectories indicated that these relationships grew in positive regard while levels of conflict decreased over time. Yet, behaviors characterizing intimate relationships did not show similar increases. Constellation variables were found to have effects on specific relationship dimensions, including conflict and intimate behaviors