Although the early behaviors associated with autism spectrum disorder have been well characterized, many behaviors are also commonly observed in young children with other developmental delays and even in those with typical development. Therefore, consideration must be given to whether a child demonstrates sufficient autism spectrum disorder…

This prospective study of the FIRST WORDS® Project examined restricted and repetitive behaviors in a sample of 55 toddlers at a mean age of 20 months who were later diagnosed with autism spectrum disorder. Restricted and repetitive behaviors were coded using the Repetitive Movement and Restricted Interest Scales in two video-recorded observation…