Repetitive and Stereotyped Behaviors From Age 2 to Age 4: A Look at the Development of High- and Low-Level Behaviors

Background:  

Restricted, repetitive, and stereotyped patterns of behaviors, interests, or activities are core features in autism spectrum disorder (ASD).  These patterns of behavior are wide ranging and include motor stereotypies, circumscribed interests, compulsions, and insistence on sameness.  Previous literature has subdivided repetitive and stereotyped behaviors (RSB) into two categories: low- and high-level behaviors.  Lower-level behaviors are characterized by repetition of movement, such as stereotyped movements, repetitive use of objects, and dyskinesias. Furthermore, this pattern of behavior is hypothesized to be associated with lower developmental levels.  Higher-level behaviors are thought to require higher cognitive abilities, and include insistence on sameness, adherence to a routine, and circumscribed interests.  There is conflicting evidence regarding the relationship between early RSB and later developmental outcomes.

Objectives:

To examine developmental differences associated with high- and low- level repetitive and stereotyped behaviors in young children diagnosed with an ASD.

Methods:

Participants were evaluated after screening positive on the Modified Checklist for Autism (M-CHAT), a developmental screener designed to identify children at risk for ASD between the ages of 16 and 30 months and receiving a developmental/diagnostic evaluation.  Participants then received a follow-up evaluation between the ages of 41 and 69 months.  Follow-up data from the ADI-R was used to categorize children as having high- and low-level RSB.  Children in the low-level group displayed repetitive motor movements (hand and finger mannerisms or stereotyped body movements) in the absence of any high-level behaviors.  Those in the high-level group displayed one or more of the following: unusual preoccupations, circumscribed interests, compulsions or rituals, or difficulty with changes in their routine or environment, without any low-level RSB.  Measures of cognitive functioning and social-communicative development were examined between the two groups at age 2.

Results:

Preliminary analyses yielded significant differences in cognitive functioning, as measured by the Mullen Scales of Early Learning, where individuals with low-level behaviors display lower standard scores on the Early Learning Composite.  Significant differences were also obtained when comparing early social skills, with parental report suggesting lower levels of social competence in individuals with low-level behaviors.

Conclusions:

The present study suggests that the development of low-level repetitive behaviors is associated with lower levels of cognitive functioning, which may interfere with social and communicative development in young children with ASD.