Early Developmental Patterns of Repetitive Behavior in Autism Spectrum Disorders

Background: While social and communication impairments have been the focus of a growing amount of research in autism spectrum disorders (ASD), little is known about the phenomenology and development of restricted repetitive behaviors (RRBs) in young children with ASD.  RRBs can cause significant impairment for individuals with ASD and their families; such rituals may consume large amounts of time and interfere with daily activities.  These behaviors may be of particular significance due to research suggesting RRBs interfere with observational learning, play skills, and responses to auditory stimuli.  Previous work has also suggested the more time a child spends engaging in RRBs, the less time he or she spends exploring his or her environment.  Thus, RRBs may replace or prevent normal exploration and experience-dependent learning during critical periods of development.  Lastly, little is known about the relationship between RRBs and problems with mood and behavior (e.g., anxiety and hyperactivity) in ASD.  Parents and caregivers often report that interruption or prevention of certain RRBs can result in increased levels of anxiety or tantrums in some children with ASD, which suggests a possible relationship between these behaviors.  

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, M_age=50.5 m), TYP (n=65, M_age=46.5 m), or DD (n=18, M_age=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.