The Real-Life Prisoner’s Dilemma (Blog Post III)

In my last post, I talked about how game theory could be applied to video games. While it was an easy to way introduce how it’s applied in a straightforward, easy-to-quantify way, it doesn’t really show how game theory is applied in real life, or in a way that actually matters to the rest of us.

A really popular topic in game theory is the concept of the Prisoner’s Dilemma. This is a situation usually described by the following scenario:

  1. Two prisoners are arrested and imprisoned. Each prisoner is separated from the other such that they cannot communicate with each other.
  2. The prosecutors, with a lack of evidence to convict either prisoner, interrogate each prisoner with hope of receiving a confession.
  3. The prosecutor offers a bargain to the prisoners. The prisoners each have the opportunity to betray the other prisoner by testifying that they committed the crime, or to cooperate with the other prisoner and remain silent. The offer goes as follows:
  • If prisoner A and prisoner B betray each other, they both serve two years.
  • If prisoner A betrays but prisoner B remains silent, prisoner A will not get jail time but prisoner B will get 3 years.
  • If both remain silent, both prisoners get only one year in prison.
Prisoner’s Dilemma Payoff Table

The prisoner’s dilemma is basically a scenario where two completely rational players may not cooperate with one another; it just makes more sense to betray the other guy to stay safe.

So, when do we see this happen in real life, outside of county jails? One example that we should all know about is the nuclear arms race that the United States had with the Soviet Union during the Cold War. See, both nations had the opportunity to either dismantle their nuclear weapons or to keep developing them. Both would benefit from dismantling the nukes, but could either nation really trust the other to follow through with that? If one nation, say the US, dismantled their nuclear weapons and the Soviets decided to keep theirs, the US would find itself extremely disadvantaged. So it makes sense that both countries kept the nukes.

We also see the prisoner’s dilemma take place in sports, specifically steroid use. Let’s say we have two baseball players who will be competing on opposing teams. If they both decide to not take steroids, they’ll be safe and both receive the most overall “benefit.” However, each player can’t trust that the other won’t be ‘roided up by the next game, since if they refrain and the opponent take the steroids, they would be at a pretty big disadvantage. Then, if they both take the ‘riods, they would even out but while accepting the risks of taking the steroids in a professional setting. This explains why steroid use can been rampant at some points in many sports.

The final place I’ll mention where the prisoner’s dilemma can be found is probably more relatable to a group of college students. Tinder is a dating app that allows the user to sift though potential “matches” by swiping left (rejecting) or swiping right (accepting) on the displayed user. If both parties swipe right, then they “match” and are able to start messaging each other. Now, let’s make a distinction about two different kinds of people who use Tinder. There is the honest swiper, who swipes right or left on the other user depending on their genuine interest in said user. Then, there’s the guy who swipes right on literally every user that comes up to get as many matches as possible. This is a prisoner’s dilemma because, if both players are honest swipers, then they both benefit from the genuine interest from the other user (mutual cooperation) upon matching. However, if one user is an honest swiper and the other is the “dishonest” swiper, it gives the dishonest swiper the advantage as he is able to decide whether or not he is interested after matching, while the honest swiper was likely interest in the other player from the start (betrayal). Then, there’s the case where both players are dishonest swipers, where neither player truly wins since both weren’t all that interested in the other user to begin with.

That wraps up this post, and I’ll see where I go from here for my next one. There’s not that much to write about game theory.