Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population's long-run steady-state level of inequality depends on the...

Experimental behavioral scientists have found consistent deviations from the predictions of the canonical model of self-interest in over a hundred experiments from around the world. Prior research cannot determine whether this uniformity results from universal patterns of behavior, or from the...