Card concept and design by Hessa Al-Ali (2018) for Qatar Museums

Climate change is known as a “wicked problem” because it is so complex and difficult to solve! A large part of this complexity is due to collective action problems: when people fail to successfully work together to achieve common goals. I’ve previously discussed the collective action problem known as the tragedy of the commons (using South Park as an example!), when people overuse a common good (such as fish) to the point of destruction. The tragedy of the commons is actually a subtype of a larger collective action problem: the prisoner’s dilemma. In this blog, let’s explore the prisoner’s dilemma, and use a card game to have fun while doing so!

A prisoner’s dilemma is a phrase that captures a difficult situation: when a person’s individual choices conflict with the goals (or best interests) of the group as a whole. A prisoner’s dilemma occurs when individuals decide that even if they support some collective undertaking, they are personally better off pursuing an individual reward—even if it undermines the collective effort! 

If you’ve watched any movies from the film noir genre, you’ve seen the prisoner’s dilemma in action! A classic example of a prisoner’s dilemma is a detective arresting two people (both of whom are involved in a shady situation) and taking them each to separate rooms for interrogation. If they both remain silent, there wouldn’t be enough evidence to convict them of much, thereby allowing them to escape with minimal jail time (say, 1 year). If they both confess, on the other hand, they would each get about 5 years of jail time. But if one of them remains silent and the other one takes a deal and spills the dirt—then the one who remained silent would suffer the full brunt of the law (serving 10 years in jail!) while the one who gave up the information would get off scot-free. The best case scenario for the pair of shady characters as a whole would be to remain silent and serve a relatively short time in jail. But the best case scenario for the individual would be to tell on the other person (while hoping that the other person doesn’t tell on them), which would let that individual avoid all jail time. By confessing to the detective, this course of action also “protects” the individual from suffering in jail alone for an extended period of time, just in case the other person is currently taking a deal too. 

This scenario is a clear example of a group goal conflicting with an individual’s personal interests. Together, if they had enough trust and communication between them, the two would be able to get off with one year of jail time each. But instead, the detective applies psychological pressure through separate interrogations, and eventually both individuals crack under the strain, choosing to take the option of either 5 years in jail (if the other person also confesses) or zero jail time, rather than risk receiving 10 years in jail while the other person gets off. And that’s the prisoner’s dilemma: Even if individuals would benefit from cooperating with each other, there are powerful and sometimes irresistible incentives to break the agreement and exploit the other side for personal advantage. Only when each party is confident that the other will live up to an agreement (through enforceable rules, social trust, and clear communication) can they successfully work to their mutual advantage!   

To help my students understand the prisoner’s dilemma, we play a card game, adapted from Charles Holt and Monica Capra’s 2000 article, “Classroom Games: A Prisoner’s Dilemma” (see ResearchGate for access!). Each student gets an instruction sheet and two playing cards (one black and one red). The instructor also gets a notes sheet to help them run the game! It’s important to make clear from the beginning that all “money earned” is hypothetical (just for fun), except for one person, who will be randomly chosen at the end of the game to receive 10% of their “winnings” as real cash. This stipulation helps the students understand that the point of the game is to maximize their “earnings,” while also saving the instructor from paying out hundreds of actual dollars!  

For five rounds, the students are paired with different people and have to decide whether to play their red or black card, each of which comes with different possible payouts. For example, in the first round, both people playing the same color card results in a positive payout for both ($2 each for red cards and $3 each for black cards). Aha, you say! Playing the black card is a good idea! But if one person plays a red card and the other plays a black card, then the red card player earns $5 while the black card player receives nothing. This round clearly pressures the students to choose to play the red cards, which are not the maximally efficient cards (that would be black) but which still provide a decent non-cooperation payoff and protect the student from non-cooperation on the other side.

With new pairs, the payoff structure changes in the second round, where playing two black cards nets both players $8 each, which is a large increase over the two red cards, which remain at $2 each. This new payoff structure opens the door for increased cooperation, although playing a red card while the other player shows a black card is still the most individually profitable scenario, garnering the red card $10. Finally, the class goes back to the original payoff structure, but this time the new pairs remain together for rounds three through five, which brings in the added elements of social pressure and repeated gameplay. For this last iteration of the game, we would expect to see high levels of maximally efficient cooperation in the first two rounds, ending with less cooperation in the final round as the students are incentivized to focus on private gain. 

Not only is this card game easy and fun, but it provides a great way of connecting the abstract vocabulary words and concepts of collective action to the specific experiences of the game. The wrap-up discussion is always lively and focused on the tensions between the gains from cooperation and the private incentives to “defect.” Social pressure and repetition are important concepts to discuss too, as they are experiential examples of the political science idea of “institutions” that can guide people toward particular choices and behaviors. 

Materials for this activity are the instructor notes sheet and the student instruction sheet, along with any deck of playing cards. Big thanks to Charles Holt and Monica Capra for developing this excellent in-class activity!


Note: Much of this material is originally from my political science lectures from our interdisciplinary “Ways of Knowing: Climate Change” course. I am available (and willing!) to present this material to a public audience!