The Context of Repetitive and Stereotyped Behaviors in Young Children with Autism Spectrum Disorders: Exploring Functions

Background: Repetitive and stereotyped behaviors (RSB) are frequently interpreted in clinical settings in terms of their apparent functions. However, few studies have systematically examined the functions of RSB in children with ASD. Therefore, there is a clear need to conduct comprehensive studies of the phenomenology of repetitive behaviors seen in ASD (Lewis & Bodfish, 1998) which would have important intervention implications.

Objectives: There were three objectives of this study: 1) to describe the functions underlying RSB in young children with ASD;  2) to compare the functions demonstrated by  children with ASD to children with developmental delays (DD) and typical development (TD); and 3) to examine the relationship between the functions and social and symbolic behaviors and autism symptoms.

Methods: Communication and Symbolic Behavior Scales (CSBS; Wetherby and Prizant, 2002) behavior samples were videotaped as a part of an ongoing longitudinal study of the FIRST WORDS^® Project. Using Noldus Pro Observer^® video software version XT, five object placement triggers, a dichotomous regulation measure, and nine function categories were created and measured within each RSB episode demonstrated during the CSBS behavior sample. Children between 18-24 months of age who displayed 3 or more RSB were selected. The 161 participants included children with ASD (n = 55), DD in which ASD had been ruled out (n = 22), TD matched on chronological age (TDCA; n = 37), and TD matched on mental age (TDMA; n = 47). Group differences between object placement, emotional regulation, and functions of RSB were examined. In addition, concurrent correlations between functions and social and symbolic behavior in the 2^nd year and predictive correlations between functions in the 2^nd year and ASD symptoms in the 4^th year were computed.

Results: Although children with ASD showed higher rates of RSB, similar object placement and function profiles were demonstrated across groups, particularly between the ASD and TD groups. Occupying self was the most common function across all groups. Self soothing and intense excitability were the least common. Children with ASD demonstrated more RSB for object focused functions than the TD groups and fewer RSB for functions related to the meaningful use of objects than children in the DD and TDCA groups. Children with ASD also demonstrated significantly lower proportions of well regulated behavior during episodes of RSB with large effect sizes than children with DD, TDCA, and TDMA.

Conclusions: These results support previous conclusions indicating that RSB may not serve a single function (Lewis and Bodfish, 1998; Reese et al., 2003; Turner, 1999) and that RSB demonstratd at this young age may appear similar in children with ASD and TD (Leekam et al., 2007).  These findings offer a systematic framework within which RSB may be functionally assessed and may contribute to intervention decision-making. The findings also provide important details about triggers and functions that broaden our understanding of RSB in young children with ASD.