Play with Me: Sibling Interactions of High-Risk Infants with Their Older Brother or Sister with Autism Spectrum Disorder

Background:

The social experience and social context of infants in their first years of life play an important role in shaping their future social interactions. In infant siblings of children with ASD, who have an increased risk of developing ASD or related social-communicative problems themselves, these social interactions may be even more important. Recently, there is increased attention for parent-child interactions in these high-risk (HR) siblings. Another important aspect of early social experience has however been largely overlooked so far: the interaction with older siblings. In the case of HR siblings, at least one of these older siblings has ASD, which will have an impact on the interaction between both children, and most probably also on the social learning opportunities of the youngest child. Therefore, this study was the first to focus on sibling interactions between HR siblings and their older brother or sister with ASD, in a longitudinal design.

Objectives:

1) To compare sibling interactions of HR siblings and their older sibling with ASD with those of low-risk (LR) control dyads and 2) to explore the possible predictive value of these interactions for the later development of HR infants.

Methods:

28 HR dyads and 34 LR dyads were seen when the youngest sibling was 18, 24 and 36 months old, as part of a larger follow-up study. Sibling interactions were observed during a naturalistic free-play session filmed at home, and positive and negative initiatives and responses of both interaction partners were coded afterwards. At 24 and 36 months, the Mullen Scales of Early Learning and the ADOS-2 were administered.

Results:

At 18 months, HR siblings responded more often in a negative way to the initiatives (both positive and negative) of their interaction partners, and so did their older brother or sister with ASD. There was no difference in the amount of positive initiatives or responses. At 24 months, HR siblings made fewer initiatives, especially positive ones, compared to the LR infants. By 36 months, the number of initiatives did not differ anymore between the groups, but both HR infants and their older sibling with ASD responded less often positive to an initiative of the interaction partner. In general, infants of both groups showed more initiatives at 36 months than at 18 and 24 months. Responsiveness of the HR infants decreased over age, while this was not the case in LR infants.

A lower number of initiatives made by the HR infants (and a lower number of responses by their older sibling with ASD) at 18 months predicted a higher ADOS score at 24 months.

Conclusions:

Sibling interactions of HR infants with their older brother or sister were characterised by more negativity and/or less positivity. In addition, in HR infants there was a decrease in responsivity over time. Sibling interaction at 18 months predicted ADOS scores at 24 months in the HR group. 36-month outcome is currently being collected, and the extent to which this is predicted by peer interaction variables will also be presented at the meeting.