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

Abstract

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.

Dopamine and stress signalling interplay patterns social organization in mice

“…Higher socio-economic status (SES) has been linked to lower evening glucocorticoid levels (Cohen et al 2006). Studies in military leaders, as well as in influential individuals from a bolivian forager-farmer population, different for individuals with higher SES, showed lower glucocorticoid levels (Sherman et al 2012, von Rueden et al 2014. We studied the social fate of mice deprived of the glucocorticoid receptor gene in dopamine innervated neurons.…”

Leadership solves collective action problems in small-scale societies

“…The ranking method did not differ qualitatively. Rather, in the two smaller villages, individuals were rated fewer times than in the two larger villages [113]. The Gini coefficients in table 2 should be interpreted relative to one another rather than as absolute measures of inequality.…”

“…Men inherit the Gini coefficients, weighted according to the maximum inequality obtainable from the leadership ranking method within each village [113].…”

Child nutritional status among births exceeding ideal family size in a high fertility population

“…The Tsimane (population approximately 16,000) occupy over 90 villages consisting of extended family groups ranging from 30 to 600 people. Villages vary in access to market goods and health care that are largely available in the market town of San Borja (population approximately 25,000 in 2010), by navigating the Maniqui River or seasonal logging roads (von Rueden et al, ). No villages have running water, and only a third contained schools teaching both Tsimane and Spanish during most of the study period.…”