In this paper, we review and integrate the contemporary literature on the societal effects of income inequality, drawing on social, personality, developmental, and organizational psychology, sociology, political science, economics, and public health. Living in highly unequal regimes is associated with both increased mistrust and increased anxiety about social status; these psychological mechanisms help explain some of the negative outcomes associated with income inequality, such as lower happiness, lower social cohesion, weaker morality, higher mortality, worse health, and weaker governance.