What role does the environment play in language development? Exploring the associations among socioeconomic status, parent language input, and language skills in school-aged children with autism

Language development in children with autism is influenced by proximal (e.g., parent language input) and distal (e.g., socioeconomic status) environmental constructs. Studies have found that "rich and responsive" parent language input supports autistic children's language development, and recent work has reported positive associations between measures of socioeconomic status (SES) and child language skills. However, little is known about how these proximal and distal environmental constructs interact to shape language development in autism. In a sample of 74 autistic school-aged children, the present study investigated the associations among measures of SES, the quantity and quality of language produced by parents and children during home-based dyadic parent-child interactions, and children's expressive and receptive language skills. Results showed that annual household income was positively associated with parent number of total words (NTW), parent number of different words (NDW), and parent mean length of utterance (MLU), while neither parent education level nor annual household income were significantly associated with measures of child language skills. Parent MLU was positively associated with child MLU and child expressive language skills. Findings suggest that annual household income may influence both the quantity and quality of parent language input, and that parent MLU, a qualitative measure of parent language input, may play a particularly important role in shaping autistic children's expressive language development. Future research should study longitudinal associations among SES, parent language input, and child language skills, as identifying environmental predictors of language skills in autism may facilitate the creation of more effective interventions that support language development.