Predicting expressive language abilities from early intentional communication in younger siblings of children with autism spectrum disorder

Abstract

This paper examines the relation between intentional communication (i.e., declaratives, imperatives) observed at 12-19 months and expressive language abilities observed one year subsequently, comparing younger siblings of children with autism spectrum disorder to younger siblings of typically developing children. For this study I use an observational coding system to quantify expressive language, adapted from a coding system devised by Professor Yoder. This study found that younger siblings of children of typically developing children were significantly better at initiating declarative intentional communication than were younger siblings of children with autism. Furthermore, results reveal a positive predictive relation between declaratives and later expressive language in younger siblings of children with ASD as well as in typically developing children. The study also shows that declaratives predict later expressive language over and above imperatives in both groups. The importance of the predictive relation between declaratives and later expressive language in this group lies in the possibility of pinpointing early markers of increased risk for ASD and autism symptamology, allowing for earlier identification as well as targets of early intervention.