Relative wealth and inequality associate with health in a small-scale subsistence society

In high-income countries, relative wealth and inequality affect health by causing psychosocial stress. We test this hypothesis in a small-scale subsistence society, the Tsimane. We associated relative household wealth (n=1003) and community-level wealth inequality (n=35, Gini = 0.15 - 0.43) with a range of psychosocial and health outcomes (depressive symptoms [n=663], social conflicts [n=393], non-social problems [n=390], social support [n=392], cortisol [n=828], BMI [n=9378], blood pressure [n=1614]), self-rated health [n=809], morbidities [n=3140]) controlling for absolute wealth, age, sex, community size, distance to town and relevant random effects. Relative wealth and inequality were associated with self-rated health and morbidity, especially respiratory disease, the leading cause of mortality in the Tsimane. Inequality was also associated with higher blood pressure. However, psychosocial stress did not mediate these associations, suggesting other mechanisms. These findings are consistent with socio-economic hierarchies affecting some health outcomes in any society, while others might be exacerbated in high-income countries.