Relations among restricted and repetitive behaviors, anxiety and sensory features in children with autism spectrum disorders

• Factor analysis using the RBQ-2 resulted in two subtypes of repetitive behavior.
• One subtype, insistence on sameness (IS), was found to be associated to anxiety.
• The association between IS and anxiety was mediated by sensory features.

The purpose of this study was to explore how atypical reactions to sensory stimuli contribute to the relation between restricted and repetitive behaviors and anxiety in children with autism spectrum disorders (ASD). In Study 1, factor analysis of restricted and repetitive behaviors was carried out using the Repetitive Behavior Questionnaire-2 (RBQ-2), completed by 120 parents of 2- to 17-year-olds with ASD. Two subtypes resulted: repetitive sensory and motor behaviors, and insistence on sameness, accounting for 40% of the variance. This two-factor solution was retained even when the sensory items of the RBQ-2 were removed. In Study 2, 49 of the same parents also completed the Spence Anxiety Scales and the Sensory Profile. The insistence on sameness factor was significantly associated with anxiety while the repetitive motor behaviors factor was not. The relation between anxiety and insistence on sameness was mediated by sensory avoiding and to a lesser extent by sensory sensitivity. Implications for arousal explanations of ASD and for clinical practice are discussed.