stressors, and has been implicated in child and adult manifestations of externalizing psychopathology (McBurnett et al., 1991; Hawes, Brennan, & Dadds, 2009; Lopez-Duran et al., 2009; Savitz, Lucki, & Drevets, 2009; Stadler, Poustka, & Sterzer, 2010; van Zuiden et al., 2011; Fardet, Petersen, & Nazareth, 2012). Particularly relevant to the current study is evidence that children exhibiting low cortisol reactivity to experimental challenge respond less favorably than high cortisol-reactive children to an intervention designed to reduce disruptive behavior (van de Wiel et al., 2004).