A Fair Society Many of the social interactions of everyday life, especially those involving economic exchange, take place between individuals who are unrelated to each other and often do not know each other. Countless laboratory experiments have documented the propensity of subjects to behave fairly in these interactions and to punish those participants deemed to have behaved unfairly. Henrich et al. (p. 1480 , see the Perspective by Hoff ) measured fairness in thousands of individuals from 15 contemporary, small-scale societies to gain an understanding of the evolution of trustworthy exchange among human societies. Fairness was quantitated using three economic games. Various societal parameters, such as the extent to which food was purchased versus produced, were also collected. Institutions, as represented by markets, community size, and adherence to a world religion all predict a greater exercise of fairness in social exchange.