Game Theory and the Narrative #2, Prisoner’s Dilemma
I’ve decided to spend some time exploring how game theory can inform an author’s perspective on the narrative. I started this in my discussion of dragon-slaying, and I enjoyed writing that. My intent with these is to learn a bit about human nature and how that can and should impact my writing.
Today, I’m going to focus on one of the best known game theory problems: the prisoner’s dilemma. As Wikipedia tells us a classic example of the prisoner’s dilemma is this:
Two suspects are arrested by the police. The police have insufficient evidence for a conviction, and, having separated the prisoners, visit each of them to offer the same deal. If one testifies for the prosecution against the other (defects) and the other remains silent (cooperates), the defector goes free and the silent accomplice receives the full 10-year sentence. If both remain silent, both prisoners are sentenced to only six months in jail for a minor charge. If each betrays the other, each receives a five-year sentence. Each prisoner must choose to betray the other or to remain silent. Each one is assured that the other would not know about the betrayal before the end of the investigation. How should the prisoners act?
Rational players, in repeated experiments, consistently choose to defect. While being silent and cooperating could have a nice payoff for both, too much trust is required to take that gamble.
What does this mean for the writer? Generally speaking, people will choose some bad over the possibility of a good if they can also defer a greater bad. In the realm of fantasy, we might rephrase the dilemma to this:
Two protagonists are captured by the antagonists and are separated. Each is offered a deal: each can choose to join the forces of darkness. If one defects and join the forces of darkness and the other stays silent, then the silent one will be killed and the defector will remain in place, perhaps to affect the final fate of the world. If both remain silent, the forces of darkness will keep them prisoner, but won’t kill them- the knowledge they have is too valuable. If both defect, the forces of darkness will have all of the knowledge it needs to destroy the world, but they are both still alive and in place with the small hope of affecting the final fate of the world.
As a translation, that’s a bit rough around the edges, perhaps, but it tells us rational protagonists may do things we, emotionally, don’t want them to do on the hope that they can achieve a pyrrhic victory.
Another thing this tells me is this: antagonists are often rational actors, protagonists rarely are. Emotionally, we want to boo the person who makes the rational choice here. Conversely, a fantasy protagonist will often hope and trust beyond reason. This is something we enjoy in them. We respect them for it. Trust and hope in others in the face of betrayal is Christ-like. Christian and non-Christian alike want such in their fantasy protagonists. Which means, in this case, a protagonist will likely short-circuit the prisoner’s dilemma. The best narrative would be to establish such a dilemma and have it seem as if the protagonist will do the rational thing. Then have him do something unexpected and heroic.