A Longitudinal Study of Parent Gestures, Infant Responsiveness, and Vocabulary Development in Infants at Risk for Autism Spectrum Disorder.

We investigated gestures that parents used with 12-, 18-, and 24-month-old infants at high or low risk for autism spectrum disorder (ASD; high-risk diagnosed with ASD: n = 21; high-risk classified as no ASD: n = 34; low-risk classified as no ASD: n = 34). We also examined infant responses to parent gestures and assessed the extent to which parent gesture relates to vocabulary development. Parents of three groups gestured in similar frequencies and proportions. Infants, in turn, responded similarly to parent gestures regardless of the infant's ASD risk and later diagnosis. Finally, parents who gestured more at 12 months had children with better vocabulary at 36 months than parents who gestured less. These findings highlight the importance of examining parent gestures when predicting language development.