Objective Within-family concordance in physiology may have implications for family system functioning and for individual health outcomes. Here, we examine patterns of association in cortisol within family triads. Methods A total of 103 adolescents and their parents sampled saliva at multiple timepoints before and after a conflict discussion task. We explored whether within-family associations existed and were moderated by stepparent presence and youth gender, and whether within-family patterns of influence correlated with individuals’ aggregate cortisol. Results Across the laboratory visit, the cortisol levels of fathers, mothers, and youth were positively associated. In time-lagged models, mothers’ cortisol predicted fathers’ cortisol levels sampled at the following timepoint, whereas fathers’ predicted youths’ and youths’ predicted mothers’ cortisol. These patterns appeared stronger in families not including stepparents. Youth gender moderated some associations: in the aggregate, youth were more strongly linked with their same-gender parent. In time-lagged models, girls were more closely linked to their mothers than boys, and both parents were more linked to girls. Youth showed higher aggregate cortisol output if they were more linked with their mothers, and lower output if more linked with their fathers; parents had higher output if they were more linked with their spouses and lower output if more linked with their children. Conclusions These results suggest that family members’ physiological activation may be linked during shared interaction, and that these patterns may be affected by family role and by youth gender. Our findings identify specific patterns of physiological influence within families that may inform family systems theories.

This longitudinal study investigated how past versus current life stresses relate to adolescents' cortisol awakening response (CAR), an index of hypothalamic-pituitary-adrenal activity. Ninety-nine adolescents reported previous year life stress at ages 12 and 18. At the second assessment, participants also provided self-reports of parent and peer attachment and 3 days of cortisol samples. Current stress was associated with heightened CAR for both males and females, whereas past stress was associated with attenuated CAR for males. Attachment to peers buffered the relationship between past stress and attenuated CAR for all adolescents; attachment to parents was a buffer for male adolescents only. Results demonstrate the protective roles of adolescent relationships and highlight sex differences in biopsychosocial development across adolescence.

Purpose To assess short-term effects of daily worries on hypothalamic-pituitary-adrenal (HPA) axis activity and later implications for adolescents’ health symptoms. We hypothesized that heightened worry would be associated with stronger next-morning cortisol awakening response (CAR) to prepare the body for the demands of the upcoming day. Guided by biological adaptation to stress theories, we also hypothesized that dysregulated CAR would heighten associations between worries and later health symptoms, while also testing direct associations between worries and dysregulated CAR and health. Methods Ninety-nine late adolescents during Waves 5 and 6 of a longitudinal study reported on 26 worries for 10 days. On three of the 10 days, participants also provided morning saliva samples that were assayed for cortisol to capture the CAR. At both waves, participants reported on 22 common health symptoms. Results Multilevel models showed significant within-person associations between high daily worries and next-morning heightened CAR for females. Contrary to expectation, worries were inversely related to concurrent health symptoms. For the whole sample, CAR moderated the effect of worries on later health symptoms: Worries were positively associated with health symptoms in adolescents with high CAR and inversely associated with health symptoms for those with low CAR. Conclusions In this sample of typically developing adolescents, worries alone do not increase the risk for common health complaints and may be somewhat protective in the short run. However, high worries in the context of high CAR appear to increase the risk for health symptoms.

This study investigates bidirectional associations between adolescents’ daily experiences of victimization and aggression perpetration within friendships. We investigated (a) across‐day associations between victimization and aggression perpetration; (b) morning cortisol activity as a moderator of cross‐day victimization and aggression links; and (c) potential sex differences in these patterns. For 4 consecutive days, 99 adolescents (Mage = 18.06, SD = 1.09, 46 females) reported whether they were victimized by or aggressive toward their friends. On three of these days, adolescents provided three morning saliva samples. Multilevel path analyses showed that across days, victimization and aggression were bidirectionally linked, but only for male adolescents. Additionally, for male adolescents, morning cortisol output (but not morning cortisol increase) moderated the association between victimization and next‐day aggression; victimization predicted greater next‐day aggression for boys with low, but not high, morning cortisol output. Findings implicate a physiological factor that may modify daily links between victimization and aggression in male adolescent friendships.