“…The release of cortisol is one of many ways by which the organism prepares itself to deal with physical or psychological challenges (Sapolsky, Romero, & Munck, 2000). Interestingly, both high and low levels of circulating cortisol have been associated with nonoptimal adult outcomes (Hsu, Garside, Massey, McAllister, & Williams, 2003;Lupien, Gillin, & Hauger, 1999;Young, Sahakian, Robbins, & Cowen, 1999), thus creating a U-shaped function relating cortisol levels to behavioral risk (see Aardal-Eriksson, Eriksson, & Thorell, 2001;Kristenson, Eriksen, Sluiter, Starke, & Ursin, 2004;Mason et al, 2001;Yehuda, Boisoneau, Lowy, & Giller, 1995).…”