Sibling outcomes and perspectives of their relationship when one child is autistic : an examination of the bidirectional relationships between autistic children and their siblings

Existing research examining the sibling relationship between autistic children and their non-autistic sibling has largely drawn on the perspectives of parents rather than those of their children. Gaining a better understanding of these relationships, from the perspective of the non-autistic sibling and their autistic brother or sister, is important in order to negate the current disparities in research. In Chapter 1 the thesis is introduced, providing an overview of sibling relationships and autism, including the historical context of autism. An introduction to current literature focusses on recent systematic reviews and meta-analyses published in the 2020 to 2023 period and is followed with a review of current empirical research on sibling relationships from the perspective of the autistic child. Chapter 2 utilised data from the Families Study to test a novel methodological approach, exploring the associations between the characteristics of autistic children and the outcomes of their non-autistic siblings (n=168). Using cluster analysis meaningful sub-groups of autistic children were identified. Findings included lower reported conflict between non-autistic siblings and their autistic brothers or sisters in the sub-group of autistic children with complex care needs and, lower sibling internalising and externalising problems. Higher conflict was evident in the relationships of the sub-group where the autistic child displayed high internalising and externalising behaviours and lower autistic traits. Chapter 3 replicated and extended the first study, using latent profile analysis. Data were drawn from the 1,000 Families Study (n=318), using similar multi-dimensionally defined characteristics to compare sibling emotional and behavioural problems and sibling relationship quality. The complex care needs group were again reporting the lowest levels of conflict in the sibling relationship. The highest conflict was reported in the sub-group with mild intellectual disabilities and high levels of externalising and internalising behaviours. Chapters 4 and 5 employed a qualitative methodology to explore the sibling relationship within the context of their autistic brother or sister’s complex care needs. In study 3 (chapter 4) 11 siblings of autistic children were interviewed. Findings suggested an association between spoken language and conflict within the sibling relationships. Study 4 (chapter 5) explored the relationships through interviews with both the autistic child and their non-autistic sibling (n=24). Evidence of disparity between the children’s perception of their relationships were found, with mostly positive accounts from the non-autistic sibling and typically ambivalent accounts from the autistic child. The findings from these four studies cumulatively provide a new understanding of the relationships between autistic children and their non-autistic siblings across three key areas: 1. The identification and relevance of subgroups of autistic children; 2. The role that spoken language plays in the sibling relationship in terms of conflict; and 3. Challenging the notion that complex care needs leads to sibling relationships that are not close.