Objective: To investigate the frequency and pattern of a wide range of restricted and repetitive behaviors in the second year of life.
Method: Parents of 139 15-month-old typically developing infants from a community sample completed the Repetitive Behavior Questionnaire-2, giving information on restricted and repetitive behaviors (e.g., stereotyped motor movements, sensory interests, routines and rituals, and preoccupations with restricted interests) seen in their children.
Results: The Repetitive Behavior Questionnaire-2 was found to be a reliable measure of these behaviors at this age and revealed a high frequency of particular types of repetitive motor movements in 15 month olds.
Conclusion: These findings have implications for the early detection of disorders characterized by high levels of restricted and repetitive behaviors, such as autism spectrum disorder.