Examination of the Communicative Deficits Associated with the Broad Phenotype of Autism in Infant Siblings of Children with Autism Spectrum Disorders

by Cassel, Tricia D

Infants with older siblings on the autism spectrum (ASD-sibs) are at risk for socio-emotional difficulties. ASD-sibs were compared to children of typically developing siblings (TD-sibs) in the Face-to-Face/Still-Face (FFSF) at 6 months and the Early Social Communication Scales (ESCS) at 8, 10, 12, 15, and 18 months. ASD-sibs exhibited non-significant trends to smile less and display more neutral affect than TD-sibs during the FFSF. There was a significant status by gender interaction such that male ASD-sibs showed less smiling and lower affective valence compared to male TD-sibs. Additionally, ASD-sibs showed a lack of emotional continuity in the FFSF. ASD-sibs displayed less initiating joint attention, initiating behavioral requesting, and responding to joint attention over time than TD-sibs. Results are discussed with respect to the social orienting model of autism.