Hostinar, Camelia Elena2014-09-172014-09-172013-08https://hdl.handle.net/11299/165790University of Minnesota Ph.D. dissertation. August 2013. Major:Child Psychology. Advisor:Megan R. Gunnar, Ph.D. 1 computer file (PDF); v, 115 pages.The goal of the present study was to investigate the impacts of social support and early life stress on individual differences in HPA axis reactivity in children (ages 9-10) and adolescents (ages 15-16). The primary aims were: 1) to experimentally manipulate the provision of social support in the laboratory and examine its effect on levels of salivary cortisol in response to the Trier Social Stress Test for Children; 2) to investigate parenting quality variables that may moderate the social buffering effect based on coding of videotaped parent-child interactions; 3) to analyze the role of early life stress (orphanage-rearing versus birth family rearing) and current social network characteristics in predicting the cortisol response; and 4) to explore age and sex differences in stress reactivity and the social buffering of stress. A sample of 162 participants was recruited, roughly equally divided between the two age groups, experimental conditions (half were exposed to a parent support condition before the stress task, whereas half received support from a stranger), early life experience (adopted or non-adopted) and by gender. Analyses of cortisol stress responses revealed that in the non-adopted group parent support provided in the laboratory significantly dampened stress reactivity in children but not in adolescents when compared to the stranger support condition. Additionally, participants reared in orphanages showed atypical patterns of HPA reactivity and of responses to social support provided before the stressor. Implications and future directions are discussed.en-USAdolescenceCortisolEarly adversityHPA axisSocial supportstressThesis or Dissertation