The relationship between cortisol and social stress in late adolescent girls' friendships

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on November 26, 2007)Vita.Thesis (Ph. D.) University of Missouri-Columbia 2007.The potential mechanisms linking early experience and temperament to coping with common peer dynamics and the stress hormone cortisol were explored for young women in two studies. Girls and women typically use friendships, specifically dyadic self-disclosure, as one means to cope with social stressors. As with any coping mechanism, self disclosure can have a range of effectiveness, with extremes resulting in maladaptive coping and increased, rather than decreased stress responses. Interactions at the extreme end of dyadic self-disclosure are characterized by the construct co-rumination, which refers to repeatedly discussing and rehashing problems, speculating about the causes and consequences of the problems, focusing on negative affect, and mutual encouragement of problem discussion (Rose, 2002). In study 1, two hundred six college women completed a series of questionnaires on their friendship, temperament, and relationship with their father. In study 2, a sub-sample was randomly assigned to tasks that involve discussing a problem with their friend (problem-talk group) or performing a non-social task (control group). Study 1 results confirmed that temperament traits such as high sociability, negative affect, and attention to affective changes increase the likelihood of adopting a co-ruminative social style within friendships, but the relation with father variables was weak. Study 2 results indicated dyads whose conversations were characterized by co-rumination, particularly dwelling on negative affect, had higher cortisol levels after their conversations compared with dyads lower on these constructs and dyads in the control group. These results suggest some aspects of temperament may place some girls at risk for excess co-rumination and engagement in this level of co- rumination can lead to a short-term spike in cortisol levels. Finally, the majority of the content of these conversations revolved around developmentally contingent issues such as male choice and same-sex friendships.Includes bibliographical reference

Rapid Cortisol and Testosterone Responses to Sex-Linked Stressors: Implications for the Tend-and-Befriend Hypothesis

Current evolutionary theories regarding the nature of hormonal responses to a variety of salient social stimuli are incomplete in yielding evidentiary support for their assertions. This study offers more nuanced evidence for the Tend-and- Befriend model of sex differences in responses to social stimuli. Participants were randomly assigned to a mortality salience prime or a control condition prior to viewing a video of an out-group threat or a video of infants crying. Cortisol and testosterone responses were assessed. The results showed that in mortality salience conditions, females showed significantly higher cortisol responses to infants crying compared to males. Further, in both mortality salience and control conditions, females showed significantly higher testosterone responses to the crying infants than males. Males showed a greater testosterone response to viewing an out-group threat. Mortality salience prime did not impact testosterone responses in either sex. Results point to a more nuanced representation of hormonal responses to social stimuli and the need for multisystem measurement

Rapid Cortisol and Testosterone Responses to Sex-Linked Stressors: Implications for the Tend-and-Befriend Hypothesis

Current evolutionary theories regarding the nature of hormonal responses to a variety of salient social stimuli are incomplete in yielding evidentiary support for their assertions. This study offers more nuanced evidence for the Tend-and- Befriend model of sex differences in responses to social stimuli. Participants were randomly assigned to a mortality salience prime or a control condition prior to viewing a video of an out-group threat or a video of infants crying. Cortisol and testosterone responses were assessed. The results showed that in mortality salience conditions, females showed significantly higher cortisol responses to infants crying compared to males. Further, in both mortality salience and control conditions, females showed significantly higher testosterone responses to the crying infants than males. Males showed a greater testosterone response to viewing an out-group threat. Mortality salience prime did not impact testosterone responses in either sex. Results point to a more nuanced representation of hormonal responses to social stimuli and the need for multisystem measurement

Adrenocortical attunement, reactivity, and potential genetic correlates among parent–daughter dyads from low-income families

Examining the multitude of influences on the development of adolescent stress responses, especially among low-income families, is a critical and understudied topic in the field. The current study examined cortisol attunement between adolescent girls and parents (mostly mothers) from predominantly low-income, single parent, ethnic minority families before and after an in-laboratory disagreement discussion task. The sample consisted of 118 adolescents (Mage = 13.79 years, 76.3% ethnic minorities, 23.7% European Americans) and primary caregivers (Mage = 40.62 years; Mdn yearly income = $24,000; 43.2% single parents; 50% living below poverty line). We investigated oxytocin receptor (OXTR rs53576) gene variations as a potential contributor to attunement within the dyad. Results showed that parents and adolescents showed stress system attunement across the disagreement task, but that parent and adolescent oxytocin receptor genotype did not impact attunement. Future studies should detail biological factors that contribute to the calibration of stress response systems of adolescents across a variety of samples, particularly those experiencing a combination of stressors

Development and validation of the Australian Aboriginal racial identity and self-esteem survey for 8-12 year old children (IRISE-C)

Introduction: In Australia, there is little empirical research of the racial identity of Indigenous children and youth as the majority of the current literature focuses on adults. Furthermore, there are no instruments developed with cultural appropriateness when exploring the identity and self-esteem of the Australian Aboriginal population, especially children. The IRISE-C (Racial Identity and Self-Esteem of children) inventory was developed to explore the elements of racial identity and self-esteem of urban, rural and regional Aboriginal children. This paper describes the development and validation of the IRISE-C instrument with over 250 Aboriginal children aged 8 to 12 years. Methods: A pilot of the IRISE C instrument was combined with individual interviews and was undertaken with 35 urban Aboriginal children aged 8-12 years. An exploratory factor analysis was performed to refine the survey and reduce redundant items in readiness for the main study. In the main study, the IRISE C was employed to 229 Aboriginal children aged 6-13 years across three sites (rural, regional and urban) in Western Australia. An exploratory factor analysis using Principal axis factoring was used to assess the fit of items and survey structure. A confirmatory factor analysis was then employed using LISREL (diagonally weighted least squares) to assess factor structures across domains. Internal consistency and reliability of subscales were assessed using Cronbach's co-efficient alpha. Results: The pilot testing identified two key concepts - children's knowledge of issues related to their racial identity, and the importance, or salience, that they attach to these issues. In the main study, factor analyses showed two clear factors relating to: Aboriginal culture and traditions; and a sense of belonging to an Aboriginal community. Principal Axis Factoring of the Knowledge items supported a 2-factor solution, which explained 38.7 % of variance. Factor One (Aboriginal culture) had a Cronbach's alpha of 0.835; Factor 2 (racial identity) had a Cronbach's alpha of 0.800, thus demonstrating high internal reliability of the scales. Conclusion: The IRISE-C has been shown to be a valid instrument useful of exploring the development of racial identity of Australian Aboriginal children across the 8-12 year old age range and across urban, rural and regional geographical locations

Regulated maturation of malaria merozoite surface protein-1 is essential for parasite growth

The malaria parasite Plasmodium falciparum invades erythrocytes where it replicates to produce invasive merozoites, which eventually egress to repeat the cycle. Merozoite surface protein-1 (MSP1), a prime malaria vaccine candidate and one of the most abundant components of the merozoite surface, is implicated in the ligand–receptor interactions leading to invasion. MSP1 is extensively proteolytically modified, first just before egress and then during invasion. These primary and secondary processing events are mediated respectively, by two parasite subtilisin-like proteases, PfSUB1 and PfSUB2, but the function and biological importance of the processing is unknown. Here, we examine the regulation and significance of MSP1 processing. We show that primary processing is ordered, with the primary processing site closest to the C-terminal end of MSP1 being cleaved last, irrespective of polymorphisms throughout the rest of the molecule. Replacement of the secondary processing site, normally refractory to PfSUB1, with a PfSUB1-sensitive site, is deleterious to parasite growth. Our findings show that correct spatiotemporal regulation of MSP1 maturation is crucial for the function of the protein and for maintenance of the parasite asexual blood-stage life cycle

Lean on me: Effects of social support on low socioeconomic-status pregnant women

This study identified how close relationships are related to low‐income pregnant women\u27s ability to cope and overall health. Previous research has shown that stress during pregnancy is related to long‐term negative physical and psychological health outcomes for both the mother and the infant. Lower socioeconomic status has been related to higher morbidity and mortality across the lifespan. Women typically rely on close relationships for social support to help reduce stress. However, stress levels can be elevated when women engage in co‐rumination. Co‐rumination is defined as excessive problem discussion with negative‐affect focus. Thirty‐one low‐income pregnant women from central Oklahoma, USA, reported their daily stressors, social support, communication habits with friends and family, and general health in a series of questionnaires at a prenatal visit. The results revealed that daily stressors, co‐rumination with friends, and the relationship with the baby\u27s father were related to physical pain and depressive symptoms. The results suggested that specific social support dynamics, such as co‐rumination, during pregnancy have implications for the health of low‐income mothers and their infants