The pervasiveness of social dilemmas has repeatedly been recognized in the great books of political philosophy. Hobbes described such a setting as a “war of all against all.” Rousseau used a stag hunt to illustrate the problem of a group needing to all work together to hunt a large animal but facing the temptation to break up into separate groups when small animals appeared on the scene that were easy to catch. A small group could catch a rabbit, but ruined the chance for the group to obtain a large animal.