Transitivity Types Predict Communicative Abilities in Infants at Risk of Autism*

To examine predictors of preschool language abilities, thirty-seven infants at high risk for Autism Spectrum Disorder (ASD) were recorded longitudinally from 5-14 months as they interacted with their caregivers and toys at home. Triadic interactions were coded, categorized as transitive, intransitive or vacuously transitive, and then related to the MacArthur Bates Communicative Development Inventory (CDI-III) and the Mullen Scales of Early Learning (MSEL) at 36 months. The results show that prior to 14 months, early transitive interactions correlate positively and intransitive interactions correlate negatively with CDI-III and MSEL scores at 36 months. By categorizing interactions between 5-14 months by transitivity, we have demonstrated that recurring triadic patterns can predict communicative abilities at 36 months.