12.6 Human Cooperation and Resource Sharing

Human cooperation and resource sharing was able to evolve because of our keen reliance on social networks. As we’ve seen with the Tragedy of the Commons, this can go awry when self-interests override the rules of public good and reciprocal exchange.

To study how various situations impact the resulting distribution of resources, anthropologists turn to Game Theory. These mathematical models provide ways to see, predict, and understand the outcomes of various social interactions. In the end, different material “payoffs” require trade offs for the players to maintain peace within their social groups. Game theory can help us understand how group size and knowledge of available resources can influence those decisions.

In their article, “The evolution of human cooperation,” Coren Apicella and Joan Silk identified four, primary games that help explain human resource sharing. These are:

• The Dictator Game: Here, a single payer is allocated a reward. Let’s say, $100. The payer can then choose whether to keep all the money or share some with the receiver. In most cases, unless closely related to the receiver, the payer will almost always keep all of the reward for themselves.
• The Ultimatum Game: Here again, a single payer is allocated a reward. Again, let’s say $100. To keep the reward, the payer must offer the receiver an amount the receiver is willing to accept. If the receiver rejects the offer, neither gets the reward. In most cases, the payer offers a split of 50/50. In some cases, especially in cultures where sharing and humility are expected norms, they may offer 40/60. And if the payer is feeling particularly plucky, they may extend an offer of 60/40. However, rarely does the payer offer $0 with a favorable outcome.
• Third-Party Punishment Game: Here, both the payer and the receiver are allocated a reward. A third player, is also given a reward and can spend part of their reward to punish the payer. If they choose to do so, the third player must give up an amount equal to the payer’s punishment to “pay” for the punishment to occur. In low cost situations, the third player often ignores the situation. After all, it is no concern of theirs whether the payer holds the door for the receiver. However, in higher stakes situations or where perceived morality is on the line, things change. Now, the third player may be willing to give up their time (and as a result, money) to serve on the jury of an alleged murder. They may also be willing to pay higher prices at the gas pump if there is a perceived economic punishment to an out-group or competitive world power. This is what happened around the United States at the beginning of the 2022 Russian invasion in Ukraine.
• Public Goods Game: Here is where things begin to touch on the Tragedy of the Commons. All players receive an equal reward. They are asked to contribute to a shared fund for the public/group’s benefit. This is not unlike the redistribution of wealth for which taxation is intended. The difference between the Public Goods Game and taxation is that payers get to decide how much to contribute (even if it is $0). The total contributions are then redistributed evenly to all players, even those who contributed $0. A calculated risk between trusting others to pay their fair share and knowing at least one person may try to cheat the system becomes crucial.

Overall, Apicella and Silk found that humans cooperate on a much larger scale than any other species. This may be due to our evolved “cheater detection” or inequity aversion, which can be measured using Game Theory’s tools and allows us to directly manage group norms.

There is one more, incredibly important game to understand if we are to come full circle on the dilemma between sharing and cooperating, or narrowly focusing on self-interests. This is the well-studied “Prisoner’s Dilemma.”