Sex Differences in Salivary Cortisol, Alpha-Amylase, and Psychological Functioning Following Hurricane Katrina Jacob M. Vigil University of New Mexico David C. Geary University of Missouri Douglas A. Granger The Pennsylvania State University Mark V. Flinn University of Missouri The study examines group and individual differences in psychological functioning and hypothalamic–pitui- tary–adrenal and sympathetic nervous system (SNS) activity among adolescents displaced by Hurricane Katrina and living in a U.S. government relocation camp (n = 62, ages 12–19 years) 2 months postdisaster. Levels of salivary cortisol, salivary alpha-amylase, depression, anxiety, distress, aggression, and self-esteem for this group were contrasted with a demographically matched no-trauma control group (n = 53). Results revealed that hurricane exposure and SNS activity moderated the relations between lower cortisol and higher internalizing behaviors. Sex-related differences were observed in behavioral adjustment and stress regulation. Implications of sex differences in biobehavioral adjustment to loss, displacement, and relocation are discussed in relation to evolutionary and developmental theory. In all cultures in which it has been studied, expo- sure to and social and material losses resulting from natural disasters is associated with increased preva- lence of severe psychological distress (e.g., Chae, Kim, Rhee, & Henderson, 2005; Weinstein, Lyon, Rothman, & Cuite, 2000). Patterns of physiological and psychological reactions to natural disasters, however, may vary with the severity and duration of the attendant losses and by normative sex-related differences in biological, social, and behavioral con- comitants of the stress response (Geary & Flinn, 2002; Taylor et al., 2000; Vigil, 2009). In both sexes, short-term physiological responses to acute stres- sors include (a) increased activation of the hypotha- lamic–pituitary–adrenal (HPA) axis, and the synthesis and secretion of glucocorticoids (i.e., corti- sol) and (b) activation of the sympathetic nervous system (SNS) and release of catecholamines (i.e., norepinephrine, epinephrine) into the bloodstream (e.g., Chrousos & Gold, 1992). In contrast, repeated and chronic stress exposure is associated with low or blunted HPA activity (e.g., low cortisol levels or flat-shallow diurnal pattern of cortisol production), potentially reflecting habituation or adaptation to these circumstances and the overall dampening of HPA reactivity (e.g., Burke, Fernald, Gertler, & Adler, 2005; Flinn, Quinlan, Turner, Decker, & Eng- land, 1996; Miller, Chen, & Zhou, 2007). Contemporary theorists speculate that individual differences in HPA axis activity may play a role in why exposure to adverse events results in major psychological disturbances for some individuals but has minimal consequences for others (e.g., Ellis, Jackson, & Boyce, 2006). Individual differences in HPA activity are correlated with internalizing prob- lem behaviors (e.g., low mood), low levels of con- trol-related beliefs, and anxiety during adolescence (e.g., Granger, Weisz, McCracken, Ikeda, & Doug- las, 1996; Klimes-Dougan, Hastings, Granger, Usher, & Zahn-Waxler, 2001). These patterns can sometimes result in prolonged symptoms of post- traumatic stress disorder (PTSD) and major depres- sion disorder, specifically, disassociation, emotional numbness, intrusive and distressful thoughts, and feelings of hopelessness, fatigue, idiopathic (cause unknown) pain, and negative self-evaluations (e.g., Ehlert, Gaab, & Heinrichs, 2001). Repeated activa- tion of HPA and SNS has also been linked to higher morbidity, including changes that may induce We thank Patricia Vigil for her assistance with data collection. Correspondence concerning this article should be addressed to Jacob M. Vigil, Department of Psychology, University of New Mexico, 1 University of New Mexico, MSC03 2220, Albuquerque, NM 87131-1161. Electronic mail may be sent to vigilj@unm.edu. Child Development, July/August 2010, Volume 81, Number 4, Pages 1228–1240 Ó 2010, Copyright the Author(s) Journal Compilation Ó 2010, Society for Research in Child Development, Inc. All rights reserved. 0009-3920/2010/8104-0014