Brief report: Repetitive behaviours in Greek individuals with autism spectrum disorder.

The main objective of this study was to examine the factor structure of restricted repetitive behaviours (RRBs) in a sample of 205 Greek individuals with Autism Spectrum Disorder (ASD), using the Repetitive Behavior Scale-Revised (RBS-R). Results show that the structure of RRBs in this Greek sample can be described using a 2-factor solution. The current study provides further, cross-cultural support for the distinction between a "high-order" factor reflecting compulsions, rituals, sameness, and restricted behaviours (CRSRB) and a "low-order" factor reflecting stereotyped movements and self-injurious behaviours (SSIB). These factors are most likely located at the top of the RRB structural hierarchy and represent general, independent constructs of ASD behaviours that can be identified not only across studies but also across cultures.