Methodological considerations when assessing restricted and repetitive behaviors and aggression
A.J. Keefer, L. Kalb, M.O. Mazurek, S.M. Kanne, B. Freedman, R.A. Vasa
Research in Autism Spectrum Disorders
•There is a relationship between repetitive behaviors and aggression in ASD.
•This relationship is influenced by the type of measure and informant.
•Teacher report and broad aggression phenotype yield the strongest relationship.
•Findings are important for researchers studying how ASD relates to aggression.
•Findings are also relevant to assessment and treatment of aggression.
Methodological issues impacting the relationship between aggression and restricted, repetitive, and stereotyped behaviors and interests (RRSBI) were examined in 2648 children and adolescents with autism spectrum disorders (ASD) using a multi-method, multi-informant analysis model to assess the effects of informant, assessment method, and aggression phenotype. Overall, a significant, but small relationship was found between RRSBI and aggression (p < .05). There was significant heterogeneity of estimates with large effect sizes observed when utilizing teacher report and a broad phenotype of aggression. Variance in estimates was attributed to differences in informant and assessment method with two times greater effect attributed to informant. Results suggest strategies to optimize future investigations of the relationship between RRSBI and aggression. Findings also provide the opportunity for the development of targeted interventions for aggression in youth with ASD.