 Pro-social behavior, such as cooperation, is challenging to explain. Evolutionary game theory predicts that individuals will forgo a public good and that individual utility maximization will win over collective cooperation. Even though this outcome is often seen in economic experiments, in broader society cooperative behavior is pervasive (Bowles &amp; Gintis 2011). Why? The traditional evolutionary explanations of human cooperation in terms of reputation, reciprocation, and retribution (Trivers 1971; R. Alexander 1987), are unsatisfactory because they do not uniquely explain why cooperation is a stable behavior. If a group punishes individuals for failing to perform a behavior, and the punishment costs exceed the benefit of doing that behavior, then this behavior will become stable regardless of its social benefits. Anti-social norms arguably take root by precisely the same mechanisms (Bicchieri &amp; Muldoon 2014). Although reputation, reciprocation, and retribution may explain how large-scale cooperation is sustained in human societies, it does not explain how the behavior emerged (Boyd &amp; Richerson 2005). Furthermore, cooperation is observed in microorganisms (Damore &amp; Gore 2012), which suggests that much simpler mechanisms are sufficient for the emergence of cooperative behavior.