One of the major questions I’ve spent the better part of the last few years trying to work up an answer to is the matter of why – in the adaptive sense – people punish others as third parties moralistically. That is to ask why people condemn and punish others for engaging in behavior perceived to be “wrong”. This is not the same question as why people take revenge on others for their behavior; that kind of punishment isn’t terribly mysterious. Chimps, for instance, will punish those who cheated them, but they seem fairly uninterested in punishing those who cheated others (Riedl, Jensen, Call, & Tomasello, 2012). Humans are a bit different in that regard: not only do we involve ourselves in the disputes of others, but we do so on behalf of people who aren’t kin or even social allies. This is rather strange behavior, even though we do not usually perceive it to be so. I’m not the only one who has attempted an evolutionary explanation for moralistic punishment, of course; in my hubris, however, I do feel that the explanation I ended up floating tends to fit the existing data better than other, contemporary theories. Today, I wanted to try and demonstrate that fit by considering some relative-recent empirical research.

“I don’t know, man; I think it might be a little baggy. Try a size down”

The paper in question (Kurzban, DeScioli, & O’Brien, 2007) concerns audience effects on punishment. Specifically, it addresses the following question: do people punish others more (as third parties) when they are being watched and their decisions are being made public, relative to when they’re anonymous? The question was examined across two experiments. In the first of these, 43 participants viewed the outcome of a previous trust game in which one player had the choice between two different outcomes: $39 for himself and $1 for the other player, or $20 for both. In this case, the player had selected the former, selfish option. The participants in question were provided with $7 and told they could spend any amount of that money – from $0 to $7 – to deduct from the selfish player. For each dollar they spent on deductions, the selfish player would lose $3. Importantly, the participants were either doing so in conditions under which their spending would be unknown to anyone but themselves (n = 24), or conditions where the experimenter would known how much each particular participant spent (n = 19). In the anonymous condition, 38% of participants spent at least some money on punishment, whereas in the public condition, 47% opted to punish something. Importantly, however, the amount punished varied between these conditions. Those in the public condition tended to spend more on punishment than those in the anonymous condition when they did. For instance, though precise numbers are not reported, approximately 20% of the participants in the public condition paid the full $7 to punish the selfish player, as compared with 0% in the private condition.

The second experiment examined peoples’ responses to a different kind of economic game – a prisoner’s dilemma – where one player attempted to cooperate with their partner, but was met with defection. In terms of the outcome, this means that rather than both players getting $25 (if both had cooperated), the cooperative partner got $0 while the defector got $30. The participants in this experiment were shown this outcome and given $10. As before, the participants could spend any amount of this $10 to deduct from the defecting player at the 3-to-1 rate. In this case, the punishment decisions would either be known by (a) no one else but the participant (n = 31), (b) the experimenter alone (n = 26), or (c) the entire group of participants (n = 30). Again, fewer participants opted to punish at all when punishment was anonymous (42%) relative to when punishment was known to either the experimenter (65%) or the whole group (67%); the amount spent on punishment increased as well (Ms = $1.06, $2.54, and $3.17, respectively). Further, those in the public conditions also tended to display more anger, disgust, and contempt at the cheating, suggesting that they were more upset by the transgression when other people were watching (or they were at least pretending to be).

The existence of audiences seemed to have an important impact on determining moralistic punishment: not only did the presence of other people affect the percent of third parties willing to punish at all, but it also positively influenced how much they did punish. In a sentence, we could say that the presence of observers was being used as an input by the cognitive systems determining moralistic sentiments. While this may sound like a result that could have been derived without needing to run the experiments, the simplicity and predictability of these findings by no means makes them trivial on a theoretical level when it comes to answering the question, “what is the adaptive value of punishment?” Any theory seeking to explain morality in general – and moral punishment in particular – needs to be able to present a plausible explanation for why cues to anonymity (or lack thereof) are being used as inputs by our moral systems. What benefits arise from public punishment that fail to materialize in anonymous cases?

“If you’re good at something, never do it for free…or anonymously”

The first theoretical explanation for morality that these results cut against is the idea that our moral systems evolved to deliver benefits to other per se. One of the common forms of this argument is that our moral systems evolved because they delivered benefits to the wider group (in the form of maintaining beneficial cooperation between members) even if doing so was costly in terms of individual fitness. This argument clearly doesn’t work for explaining the present data, as the potential benefits that could be delivered to others by deterring cheating or selfishness do not (seem to) change contingent on anonymity, yet moral punishment does. 

These results also cut against some aspects of mutualistic theories for morality. This class of theory suggests that, broadly speaking, our moral sense responds primarily to behavior perceived to be costly to the punisher’s personal interests. In short, third parties do not punish perpetrators because they have any interest in the welfare of the victim, but rather because punishers can enforce their own interests through that punishment, however indirectly. To place that idea into a quick example, I might want to see a thief punished not because I care about the people he harmed, but rather because I don’t want to be stolen from and punishing the thief for their behavior reduces that probability for me. Since my interests in deterring certain behaviors do not change contingent on my anonymity, the mutualistic account might feel some degree of threat from the present data. As a rebuttal to that point, the mutualistic theories could make the argument that my punishment being made public would deter others from stealing from me to a greater extent than if they did not know I was the one responsible for punishing. “Because I punished theft in a case where it didn’t effect me,” the rebuttal goes, “this is a good indication I would certainly punish theft which did affect me. Conversely, if I fail to punish transgressions against others, I might not punish them when I’m the victim.” While that argument seems plausible at face value, it’s not bulletproof either. Just because I might fail to go out of my way to punish someone else who was, say, unfaithful in their relationship, that does not necessarily mean I would tolerate infidelity in my own. This rebuttal would require an appreciable correspondence between my willingness to punish those who transgress against others and those who do so against me. As much of the data I’ve seen suggests a weak-to-absent link in both humans and non-humans on that front, that argument might not hold much empirical water.

By contrast, the present evidence is perfectly consistent with the association-management explanation posited in my theory of morality. In brief, this theory suggests that our moral sense helps us navigate the social world, identifying good and bad targets of our limited social investment, and uses punishment to build and break relationships with them. Morality, essentially, is an ingratiation mechanism; it helps us make friends (or, alternatively, not alienate others). Under this perspective, the role of anonymity makes quite a bit of sense: if no one will know how much you punished, or whether you did at all, your ability to use punishment to manage your social associations is effectively compromised. Accordingly, third-party punishment drops off in a big way. On the other hand, when people will know about their punishment, participants become more willing to invest in it in the face of better estimated social return. This social return need not necessarily reside with the actual person being harmed, either (who, in this case, was not present); it can also come from other observers of punishment. The important part is that your value as an associate can be publicly demonstrated to others.

The first step isn’t to generate value; it’s to demonstrate it

The lines between these accounts can seem a bit fuzzy at times: good associates are often ones who share your values, providing some overlap between mutualistic and association accounts. Similarly, punishment, at least from the perspective of the punisher, is altruistic: they are suffering a cost to provide someone else with a benefit. This provides some overlap between the association and altruistic accounts as well. The important point for differentiating these accounts, then, is to look beyond their overlap into domains where they make different predictions in outcomes, or predict the same outcome will obtain, but for different reasons. I feel the results of the present research not only help do that (inconsistent with group selection accounts), but also present opportunities for future research directions as well (such as the search for whether punishment as a third party appreciably predicts revenge).

References: Kurzban, R., DeScioli, P., & O’Brien, E. (2007). Audience effects on moralistic punishment. Evolution & Human Behavior, 28, 75-84.

Riedl, K., Jensen, K., Call, J., & Tomasello, M. (2012). No third-party punishment in chimpanzees. Proceedings of the National Academy of Science, 109, 14824–14829