A moderated mediation model for predicting acceptance of a sibling with autism or Down Syndrome

Within the family system, the sibling subsystem holds particular importance, especially when there is a family member with a disability. Typically-developing siblings increasingly assume caregiving responsibilities for a brother/sister with a disability, particularly during the life stage of emerging adulthood. A critical factor influencing sibling relations is the acceptance of the sibling with a disability. Guided by the salutogenic approach, which emphasizes factors that promote health and effective coping, this study explored a moderated mediation model to examine the relationships between sense of coherence and emotions (active negative, passive negative, and positive emotions) toward siblings with autism or Down Syndrome, and how these relate to sibling acceptance. The sample included 520 emerging adult siblings (aged 18-27) of individuals with autism or Down Syndrome, who completed four self-report questionnaires. Disability type significantly moderated the indirect effect of the mediation relationship between sense of coherence and acceptance via active negative and positive emotions, but not via passive negative emotions. Specifically, the mediation effect via active negative emotions was significantly stronger for siblings of individuals with autism compared to those with Down Syndrome (b = 0.105), and the mediation effect via positive emotions was significant for siblings of individuals with autism but not for siblings of individuals with Down Syndrome (b = 0.137). The results highlight the role of sense of coherence in fostering sibling acceptance, mediated by emotions, and emphasize the need for community-based programs that enable siblings to process their feelings toward their siblings with autism or Down Syndrome, in order to promote acceptance.