Younger siblings of children with autism spectrum disorders (HR-Sibs) are at elevated risk for social communication deficits and language delays. One way to mitigate this risk early, before these deficits and delays become clear or impairing, may be to equip parents to use the strategies taught through the "Improving Parents as Communication…

We examined differences between children with autism spectrum disorder and typically developing children over an 8-month period in: (a) longitudinal associations between expressive and receptive vocabulary and (b) the extent to which caregiver utterances provided within an "optimal" engagement state mediated the pathway from early…