Imitation (rather than core language) predicts pragmatic development in young children with ASD: a preliminary longitudinal study using CDI parental reports

Background: Research in the last decades has clearly pointed to the important role of language and communicative level when trying to understand developmental trajectories in children with autism spectrum disorders (ASD). Aims: The purpose of this longitudinal study was to investigate whether (1) core language skills, measured as expressive vocabulary and grammar, and/or (2) pre-linguistic social-communicative skills, including gestures and imitation abilities, drive pragmatic language development in young children with ASD. Methods & Procedures: We examined correlates and longitudinal predictors of pragmatic growth in a sample of 34 children with Autism spectrum disorder (ASD), whose parents were given parts of twoMacArthur Communicative Developmental Inventories (CDI: Words & Gestures and CDI: Words & Sentences) for completion at two time points (at time 1 the mean child age was 41 months, and at time 2 it was 54 months). A novel feature in this study is that the relevant parts from both CDI forms were included at both time points, allowing us to examine whether pre-linguistic social-communication skills (e.g. imitation and gesturing) and/or core language skills (i.e. grammar and vocabulary) predict pragmatic language growth. Outcomes & Results: The results show that basically all pre-linguistic, linguistic and pragmatic skills were associated concurrently. When controlling for possible confounders and for the autoregressive effect, imitation skills predicted pragmatic growth over time, whereas core language did not. This could only have been shown by the use of both CDI forms. Conclusions & Implications: This preliminary study may be of both conceptual and methodological importance for research in the field of language and communication development in ASD. Imitation may play a pivotal role in the development of subsequent conversational pragmatic abilities in young children with ASD. Future research should be directed at unravelling the mechanisms underlying this association