Across small-scale societies, the practice of some males taking multiple wives is thought to be associated with extreme disparities of wealth. But in fact, polygyny has been more common among relatively egalitarian low-tech horticulturalists than in highly unequal, capital-intensive agricultural societies. This surprising fact is known as the polygyny paradox, and a new study from the Santa Fe Institute’s Dynamics of Wealth Inequality Project provides a possible resolution of the puzzle.