Somit and Peterson seek to explain two apparently contradictory yet well-established political phenomena: First, throughout human history, the vast majority of political societies have been authoritarian. Second, notwithstanding this pattern, from time to time, democracies do emerge and some even have considerable stability. A neo-Darwinian approach can help make sense of these observations. Humans-social primates-have an inborn bias toward authoritarian life, based on their tendency to engage in dominance behavior and the formation of dominance hierarchies. Reinforcing this bias is an impulse toward obedience. These factors are associated with the propensity of humans to accept authoritarian systems.Nonetheless, the authors argue, conditions of material abundance combined with another human characteristic-indoctrinability-can foster the emergence and maintenance of democracies. Somit and Peterson assert that an understanding of human nature from an evolutionary perspective can help to explain how and why political systems have developed. They conclude by pointing to policy implications that might enhance the odds of formation and continuation of democratic forms of government. Students and scholars of political science and philosophy, sociology, and human biology will find this an intriguing study.