Academic self-concept and sense of school belonging of adolescent siblings of autistic children

•The school context has often been omitted from research in sibling groups.•Academic self-concept and school belonging are key factors in understanding school experience.•Siblings of autistic children reported poorer academic self-concept and sense of school belonging.•Group differences remained when controlling for potential confounding variables.•We report large variability in sibling outcomes, highlighting the importance of differentiation. Whilst there is a growing body of research on the psychological outcomes for siblings of autistic children (autism siblings), few studies have considered the school context. To explore group differences on two school-related self-reported outcomes for autism siblings and siblings of non-autistic children: sense of school belonging, and academic self-concept. Data on self- and parent/carer-reported behavioural and emotional problems were also collected. 65 autism siblings and a comparison group of 57 siblings of non-autistic children aged 11–16 years completed questionnaires measuring sense of school belonging, academic self concept, and behaviour problems. 73 parents in the autism sibling and 67 parents in the comparison sibling group completed the behaviour problems measure. Autism siblings reported significantly lower school belonging and academic self-concept, and had significantly poorer self- and parent- reported behaviour problems. When controlling for demographic variables and internalising and externalizing behaviour, robust sibling group differences on academic variables remained. Autism siblings reported poorer school-related outcomes and increased behavioural difficulties relative to siblings of non-autistic children. There was wide variation in autism siblings’ outcomes, highlighting the importance of taking an individualised and contextualised approach to understanding the varying needs of autism siblings.