Early Behavioral and Environmental Predictors of Language Skills in Infants at High and Low Risk for Autism Spectrum Disorder

Abstract

Autism spectrum disorder (ASD) is characterized by deficits in social communication and repetitive and stereotyped behaviors. In addition to having the core features of the disorder, approximately 70% of children with ASD experience language delays and deficits. Language skill is one of the most robust predictors of long-term social and educational outcomes of children. Thus, finding reliable predictors of language skills is important for early identification of children who need language interventions and the development of effective prevention and intervention strategies promoting optimal child language development. Despite recognition of the importance of language skills, our knowledge of the factors that set the foundation for early language learning, especially in infants at risk for ASD, remains limited. This dissertation examines early behavioral and environmental factors associated with language development in infants at high and low familial risk for ASD, using a prospective, longitudinal design. In Study 1, I investigate developmental trajectories of fine motor skills between 6 and 24 months in relation to expressive language skills at 36 months. In Study 2, I examine the extent to which early gesture production at 12 months predicts 24-month receptive language skills and eventual ASD diagnosis. In Study 3, I explore relations between parent input and child language development between 12 and 36 months. Together, these three studies contribute to the field’s effort to identify early emerging factors that predate and predict language skills in ASD high- and low-risk infants.