Abstract
The present study examined daytime sleep patterns in 3 groups of preschool-aged children: children with autism, children with developmental delay, and children who were developing typically. Sleep was assessed in 194 children via actigraphy and parent-report sleep diaries for 7 consecutive days on 3 separate occasions over 6 months. Children with autism napped less often and for shorter periods of time than children with developmental disability, with whom they were matched on chronologic age. Children with developmental disabilities napped more like children in the typically developing group, who were, on average, 6 months younger. Each group displayed an expected shift in daytime sleep as more children matured out of their naps.