Prisoner’s Dilemma-Explained by 22-Year Old Me

For some reason, I’ve been thinking a lot about Prisoner’s Dilemma lately. Maybe it’s because of all this talk about the threats from North Korea (although, we cannot assume little Kim Jong-un is rational), or maybe it is simply because I really miss my political theory and philosophy classes and discussions. Either way, I dug up one of my final exam responses to a question about Prisoner’s Dilemma. I will post it as today’s entry. Consider this your political theory lesson for the week.

            The original Prisoners’ Dilemma presents a game to be played between two parties who try to figure out outcomes when given certain alternatives from which to choose.  These agents are rational, and are choosing among alternatives that each have different outcomes. Each player gets a payoff depending on what the other one chooses.  Of course, each agent wants to select an outcome that has the highest utility for himself, while trying to figure out what the other will pick. Suppose these prisoners cannot speak to each other, and must make a decision based upon the alternatives without knowing ahead of time what the other will choose. Because each agent does not know what alternative the other will decide upon, he must make a rational decision based on what he thinks would be the best outcome if the other chooses one particular alternative over another. For example, if both prisoner A and B choose option 1, then A gets 3 years in prison and so does B. If A chooses option 1 and B chooses option 2, then A gets one year in prison and B gets four. If A chooses option 2 and B choose option 1, A gets 4 years in prison, and B gets one. Finally, if both prisoners choose option 2, then they both get 2 years in prison.  If both prisoners are being rational, they will end up with a sub-optimal outcome, because they will be attempting to avoid the worst possible outcome for themselves. Rational agents would both choose option 2, where they each get 2 years in prison. If A chooses 1, which would be the best outcome for him if B chooses 2, B might choose 1, and then they will both have 3 years in prison. Whereas, if B chooses 1, which would be the best outcome for him if A picks 2, but A picks 1 instead, then B has four years in prison.  Therefore, each will select option 2, for fear of getting the bad end of the deal. In the original Prisoners’ Dilemma, one must choose an exploited outcome, or lose.

            The rationality involved with Prisoners’ Dilemma is deeply contextual. One’s choice may vary with context and talent in the area of conflict.  With this game, people must learn to win while others are trying to win. Rational decisions depend heavily on what others choose as well.  This concept is very important in liberal political theory because of the emphasis on the individual, and the egoist tendencies that go along with rational individuals. Because theorists such as Hobbes start to recognize individuals as separate from the group, it is important in order to survive to understand what each separate, self-interested person is choosing as their alternative. People can better plan and work together if they are basing their decisions off of what they think others might do.  In order to derive political institutions from very different individuals, who may conceal their true thoughts, one must be aware of all the alternatives and their outcomes.  Reason is the basis for installing conditions of order and security in a modern liberal political society, therefore, when making decisions for the group, it is important to choose rationally. This rational choice may cause a sub-optimal outcome for the group, but if both parties in the conflict use rationality, then the worst possible outcome can be avoided.

            Within political structures, there can be several types of conditions that people are working with. There can be conditions of certainty, where an alternative will cause a certain outcome with the probability of one. There are conditions of risk, where a particular alternative can have various outcomes with probabilities between zero and one. Or there can be conditions of uncertainty, where an alternative can have various outcomes with no probabilities. With conditions of certainty it is rational to choose the alternative that produces the best outcome. In conditions of risk, one should combine the expected values with probabilities to get the maximum utility. However, conditions of uncertainty are trickier and call for three different rules. The rule of dominance calls for selecting an alternative if all its outcomes are better than all the outcomes from any other alternative. The rule of maximax says to choose the alternative with the best best outcome, and the rule of maximin says to select the alternative with the best worst outcome. It is important to use these rules in modern societies when dealing with people of all different backgrounds and moral standards. Most decisions are not in conditions of certainty, especially when dealing with distinct individuals or foreign governments. Depending on the situation, one should employ these rules to ensure the best outcome for the circumstances. The outcome actually achieved may not be the preferred one by each party, but it would not be the worst outcome for both parties. If both parties would cooperate fully with each other, the best outcome could be achieved for both. However, oftentimes, individuals or governments are unwilling to cooperate with each other, and therefore, each party must come to a decision on his own.  In the pluralistic society that exists today, there may be those who are disinclined to working with the liberal system. Thus, the question arises of how to deal with these individuals. Using the idea of rationality in decision-making presented by the Prisoners’ Dilemma, liberal societies can better make decisions involving these individuals, assuming they are rational as well.  This goes for dealing with foreign governments also.  Certain conflicts such as an arms race may call for rational decision-making while considering what the other side is planning. Without the certainty of knowing exactly what the other player in the game might do, as in a liberal political society, it is absolutely necessary to choose an alternative based on rational decision-making as shown by the example of the Prisoners’ Dilemma. 

Jacqueline Coleman

University of Miami

2007 or 2008 (I really can’t remember)

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