 Another family of findings that is puzzling from the point of view of classical economic rationality shows that individuals will routinely punish others even at a cost to themselves (Fehr &amp; Gachter 2002; J. Henrich, McElreath, et al. 2006). Evidence suggests that this propensity to punish is influenced by norms and other cultural factors as well (Bone, McAuliffe, &amp; Raihani 2016). For example, in public goods games participants are given a non-trivial sum of money and must decide if and how much to contribute to a common pool over the course of several rounds. How much each investment pays off depends on how much everyone collectively contributes that round, so each participant’s decisions should factor in the behavior of every other participant. In some versions, participants can also spend their money to punish others, based on knowledge of the contributions they have made. Results indicate that some participants are willing to incur a cost to themselves to sanction low contributors, but also to punish high contributors, a surprising phenomenon called anti-social punishment. Participants from different cultures exhibit different patterns in their willingness to punish others, including in their enthusiasm for anti-social punishment (Herrman, Thöni, and Gächter 2008). Another noteworthy aspect of punitive behavior revealed by behavioral economic experiments is that humans are willing to punish even when they are mere bystanders to the incident that they are responding to. In such cases of third-party punishment, an individual enforces a norm despite the fact that she is neither the offender who commits the violation and becomes the target of the punishment, nor the offended who was wronged or the victim affected by the transgression (Fehr &amp; Fischbacher 2004; though see Bone, Silva, &amp; Raihani 2014).