Uljarević M, Cooper MN, Bebbington K, et al. - Researchers conducted the largest exploration to date of the link between Repetitive Motor Behaviours, Rigidity/Insistence on Sameness and Circumscribed Interests with other individual characteristics in newly diagnosed individuals with autism spectrum disorder (ASD). Using the Western Australian (WA) Register for ASD, they assessed demographic and diagnostic data of newly diagnosed cases of ASD in WA (N = 3,647; 17.7% females; Mage = 6.6 years [SD = 4.7]). The analysis revealed weak associations between restricted and repetitive pattern of behaviors and interests (RRB) domains, indexed by Kendall's Tau, ranging from non-significant for both Circumscribed Interests and Repetitive Motor Behaviours to significant (.20) for Insistence on Sameness and Repetitive Motor Behaviours. They identified a significant link of older age at diagnosis with lower Circumscribed Interests and with higher Insistence on Sameness and Repetitive Motor Behaviours. A significant association of male gender with higher Repetitive Motor Behaviours was observed however, it did not associate with Insistence on Sameness or Circumscribed Interests. These pattern of associations affords intriguing evidence for the distinctiveness of Repetitive Motor Behaviours, Insistence on Sameness and Circumscribed Interests, indicating the probable utility of RRB domains for stratifying the larger ASD population into smaller, more phenotypically homogeneous subgroups that can aid to promote attempts to understand distinct ASD etiology and inform the design of future interventions.