Early Developmental Patterns of Repetitive Behavior in Autism Spectrum Disorders
Objectives: To describe and compare the phenomenology and development of RRBs in young children with ASD to those that occur in typical development (TYP) and developmental delay (DD), and to identify types of mood and problem behaviors that may be associated.
Methods: The sample included children between the ages of 2 and 5 years, with either ASD (n=62, Mage=50.5 m), TYP (n=65, Mage=46.5 m), or DD (n=18, Mage=49.0 m). A set of standardized, psychometrically-sound parent rating scales were used to measure the domains of interest. The Repetitive Behavior Rating Scale-Revised (RBS-R) is a 43-item rating scale and was used to measure 5 types of repetitive behavior: Stereotyped Behavior, Self-Injurious Behavior, Compulsive Behavior, Ritualistic/Sameness Behavior, and Restricted Behavior. Mood and problem behaviors were assessed using the Nisonger Child Behavior Rating Form (NCBRF), a 70-item questionnaire developed to assess behavior and emotional problems in children, such as anxiety and conduct problems.
Results: Results suggest that a variety of RRBs are more prevalent in children with ASD (all ps < .001) beginning at age 2. Specifically, levels of both Ritualistic/Sameness behavior and Restricted Interests were found to be significantly higher in ASD (p < .01), but did not differ between TYP and DD. Cross-sectional analyses revealed that all types of RRBs increased from age 2 to 5 in the ASD group only (ps < .05). In ASD, anxiety was strongly associated with the presence of “higher level” (e.g., Ritualistic/Sameness) RRBs (p < .001).
Conclusions: Our findings suggest that a variety of repetitive behaviors emerge early in children with ASD, with Ritualistic/Sameness and Restricted Interests behaviors specifically increased in occurrence with respect to ASD. Additionally, the association between RRBs and mood/problem behaviors in ASD indicates these behaviors (particularly anxiety) could play a role in the expression of RRBs.