Abstract
PURPOSE: Verb production in childhood predicts language outcomes in adulthood for individuals on the autism spectrum, but few studies have investigated early verb production in ASD, and methodological differences have led to conflicting results. Thus, the purpose of this study was to explore development of verb production in children with autism spectrum disorder (ASD) and typically developing (TD) children. METHODS: We analyzed verb production via language samples from 67 children (N(ASD) = 32; N(TD) = 35) during parent-child play. RESULTS: We found that verb production increased over time in both the ASD and TD groups, but the TD group increased at a faster rate. However, latent class analysis of verb trajectories yielded three profiles of verb development, the lowest of which consisted entirely of children with ASD and was driving the group difference. We also found that longitudinal analysis can contribute to our understanding of verb development: our latent class analysis of trajectories revealed more nuance than a single-datapoint clustering method, and early verb vocabulary growth predicted later language outcomes for children with ASD. CONCLUSION: Our results suggest that while some children with ASD experience persistent challenges in verb vocabulary growth, others demonstrate similar verb growth to their TD peers. Future work will investigate early factors that differentiate children whose verb production progresses from children whose verb production stays constant over time.