Background: Both siblings and parents are important interactional partners for children with ASD, but we know little about whether these interactions differ between these two groups, or between older and younger siblings.

Aims: To gather data about how parents perceive the interactional behaviors displayed by their child with ASD in play with their typically developing siblings and their parents.

Methods and procedures: Parents completed a questionnaire developed for this study about the behaviors their children with ASD demonstrated when interacting with a sibling or parent. Following factor analysis, a 29-item instrument with two factors was revealed. Factors were labelled Prosocial Interaction and Withdrawal/Agonism.

Outcomes and results: In some families, children with ASD were reported to display significantly higher levels of negative interaction when playing with their older siblings in comparison to younger siblings. When playing with their children with ASD, parents reported significantly more negative interactions compared to when their children with ASD played with younger siblings. There were few differences reported for play behaviors with parents versus older siblings.

Conclusions and implications: Children with ASD appear to display different interactional behaviors depending upon their play partners within the family unit. This study could be used to inform researchers of different interaction strategies which may be useful in creating interventions.