“…Autism spectrum disorder (or autism) is associated with a high prevalence of sleep and behavioral difficulties. Prior research indicates that 40-80% of individuals with autism experience problems with sleep [Allik, Larsson, & Smedje, 2008;Anders, Iosif, Schwichtenberg, Tang, & Goodlin-Jones, 2011;Rzepecka, McKenzie, McClure, & Murphy, 2011] and 64-93% exhibit at least one challenging behavior (i.e., behaviors that are physically dangerous or impact learning; e.g., aggression, self-injury, or tantrums) [Hattier, Matson, Belva, & Horovitz, 2011;Matson, Mahan, Hess, Fodstad, & Neal, 2010]. Although the association between sleep and behavior has been investigated in adults and individuals with highfunctioning autism [AlBacker & Bashir, 2017;Fadini et al, 2015;Goldman et al, 2011;Hirata et al, 2016;Hollaway, Aman, & Butter, 2013;Mayes & Calhoun, 2009;Mazurek & Sohl, 2016], these relationships are yet to be studied in individuals with low-functioning autism (i.e., individuals with severe intellectual and social-communication impairment) [Cohen, Conduit, Lockley, Rajaratnam, & Cornish, 2014].…”