Purpose: A recent approach to identifying early markers of risk for autism spectrum disorder (ASD) has been to study infants who have an older sibling with ASD. These infants are at heightened risk (HR) for ASD and for other developmental difficulties, and even those who do not receive an eventual ASD diagnosis manifest a high degree of…

Studied across a 16-month period, young children of deaf parents showed accelerated early language development, on the average producing their first recognizable sign at 8.5 months, their tenth sign at 13.2 months, and their first sign combination at 17.0 months. Findings are inconsistent with previously reported patterns of synchrony between…