Stress as adaptation? A test of the adaptive boost hypothesis among Batswana men

Mental health research in Botswana: a semi-systematic scoping review

Mental and substance use disorders are a leading cause of disability worldwide. Despite this, there is a paucity of mental health research in low- and middle-income countries, especially in sub-Saharan Africa. We carried out a semi-systematic scoping review to determine the extent of mental health research in Botswana. Using a predetermined search strategy, we searched the databases Web of Science, PubMed, and EBSCOhost (Academic Search Complete, CINAHL with Full Text, MEDLINE, MEDLINE with Full Text, MLA International Bibliography, Open Dissertations) for articles written in English from inception to June 2020. We identified 58 studies for inclusion. The most researched subject was mental health aspects of HIV/AIDS, followed by research on neurotic and stress-related disorders. Most studies were cross-sectional and the earliest published study was from 1983. The majority of the studies were carried out by researchers affiliated to the University of Botswana, followed by academic institutions in the USA. There seems to be limited mental health research in Botswana, and there is a need to increase research capacity.

Political influence associates with cortisol and health among egalitarian forager-farmers

BACKGROUND AND OBJECTIVES

Low social status increases risk of disease due, in part, to the psychosocial stress that accompanies feeling subordinate or poor. Previous studies report that chronic stress and chronically elevated cortisol can impair cardiovascular and immune function. We test whether lower status is more benign in small-scale, relatively egalitarian societies, where leaders lack coercive authority and there is minimal material wealth to contest.

METHODOLOGY

Among Tsimane' forager-horticulturalists of lowland Bolivia, we compare informal political influence among men with urinary cortisol, immune activation (innate and acquired), and morbidity as assessed during routine medical exams.

RESULTS

After controlling for potential confounds, we find that politically influential men have lower cortisol, and that this association is partly attributable to access to social support. Cortisol is positively associated with men's income, which may reflect chronic psychosocial stress from market involvement. Greater influence is also associated with lower probability of respiratory infection, which is a frequent source of morbidity among Tsimane'. Among men who lost influence over a 4-year period, cortisol and probability of respiratory infection were higher the greater the decline in influence.

CONCLUSIONS AND IMPLICATIONS

Deleterious effects of low status on health are not merely 'diseases of civilization' but may result from how (even subtle) status differences structure human behavior.

Night Owl Women are Similar to Men in Their Relationship Orientation, Risk-taking Propensities, and Cortisol Levels: Implications for the Adaptive Significance and Evolution of Eveningness

Individual differences in morningness/eveningness are relatively stable over time and, in part, genetically based. The night-owl pattern is more prevalent in men than in women, particularly after puberty and before women reach menopause. It has been suggested that eveningness evolved relatively recently in human evolutionary history and that this trait may be advantageous to individuals pursuing short-term mating strategies. Consistent with this hypothesis, eveningness is associated with extraversion, novelty-seeking, and in males, with a higher number of sexual partners. In this study, I investigated whether eveningness is associated with short-term relationship orientation, higher risk-taking, and higher testosterone or cortisol. Both female and male night-owls were more likely to be single than in long-term relationships than early morning individuals. Eveningness was associated with higher risk-taking in women but not in men; this association was not testosterone-dependent but mediated by cortisol. Female night-owls had average cortisol profiles and risk-taking tendencies more similar to those of males than to those of early-morning females. Taken together, these findings provide some support to the hypothesis that eveningness is associated with psychological and behavioral traits that are instrumental in short-term mating strategies, with the evidence being stronger for women than for men.

Beyond allostatic load: Rethinking the role of stress in regulating human development

How do exposures to stress affect biobehavioral development and, through it, psychiatric and biomedical disorder? In the health sciences, the allostatic load model provides a widely accepted answer to this question: stress responses, while essential for survival, have negative long-term effects that promote illness. Thus, the benefits of mounting repeated biological responses to threat are traded off against costs to mental and physical health. The adaptive calibration model, an evolutionary–developmental theory of stress–health relations, extends this logic by conceptualizing these trade-offs as decision nodes in allocation of resources. Each decision node influences the next in a chain of resource allocations that become instantiated in the regulatory parameters of stress response systems. Over development, these parameters filter and embed information about key dimensions of environmental stress and support, mediating the organism's openness to environmental inputs, and function to regulate life history strategies to match those dimensions. Drawing on the adaptive calibration model, we propose that consideration of biological fitness trade-offs, as delineated by life history theory, is needed to more fully explain the complex relations between developmental exposures to stress, stress responsivity, behavioral strategies, and health. We conclude that the adaptive calibration model and allostatic load model are only partially complementary and, in some cases, support different approaches to intervention. In the long run, the field may be better served by a model informed by life history theory that addresses the adaptive role of stress response systems in regulating alternative developmental pathways.