“…In studies with clinical samples, higher perfectionism/certainty beliefs were associated with greater symmetry symptoms (Calamari et al, 2006;Viar, Bilsky, Armstrong, & Olatunji, 2011;Wheaton, Abramowitz, Berman, Riemann, & Hale, 2010), ordering symptoms (Calleo, Hart, Björgvinsson, & Stanley, 2010;Tolin, Brady, & Hannan, 2008), hoarding and obsessing (Tolin et al, 2008), and checking behaviors (Julien, O'Connor, Aardema, & Todorov, 2006). Research using nonclinical samples demonstrated that perfectionism/certainty beliefs were associated with washing, checking, and ordering symptoms (Myers, Fisher, & Wells, 2008;Wu & Cortesi, 2009).…”