Game theory for Christians

The “prisoner’s dilemma” shows why it is essential for Christians to hang together

A visual representation of the prisoner’s dilemma. If this means nothing to you, don’t worry—the explanation in the text should be clearer.

I have no one else like [Timothy], who takes a genuine interest in your welfare. For everyone looks out for his own interests, not those of Jesus Christ. —Philippians 2:20–21

Recent political events have shown the relevance of game theory to politics. Christians should pay attention, as we often face similar situations.

(If you already know the prisoner’s dilemma, you can skip three paragraphs while I explain it to other readers.)

The classic version of the prisoner’s dilemma, a famous example of game theory, is as follows. Two people have been arrested and charged with a crime. They are being held separately and cannot communicate with each other. Each one is asked to testify against the other. If both remain silent, each one will get a year of jail time. If both testify against each other, they get three years each. If one remains silent and one testifies, the tattler goes free but the one who did not tattle gets a five-year sentence.

What should the prisoners do? If they could communicate with each other (and knew that their colleague would remain true to their word), they could agree to remain silent and get the best cumulative result, a total of two years in jail (one year each). But for each individual, testifying is the better option regardless of what the other suspect does.

The prisoner’s dilemma shows why group members who could obtain the overall best result by working together fail to achieve that result due to a primary focus on their own self-interest. In the simulation, the prisoners have no chance to cooperate. However, the same dynamic frequently prevails in situations where people do have a chance to cooperate but choose not to.

This year, the Trump administration has accused dozens of universities of discriminatory behavior and threatened to withhold federal funding from them. After one of them, Columbia University, agreed to pay a $200 million fine, a prominent commentator expressed amazement that the universities were not banding together in a coalition to resist the threat.

That commentator doesn’t understand game theory well enough. Sure, the universities would do best as a group if all of them resisted. But as game theory demonstrates, since they can’t trust their peers to stand firm, each individual university is tempted to take the best deal they can get. Once Columbia makes a deal, it becomes harder for other institutions, such as Harvard, to maintain their determination to fight.

Similarly, the world’s nations might gain long-term benefit if they all agreed not to negotiate with the US until it returned to a predictable, collaborative trade policy. But when a country prioritizes its own economic self-interest, game theory suggests that its best strategy is to negotiate a good deal quickly, before other countries negotiate their own deals and weaken the holdouts’ position further.

When do Christians encounter the awkwardness of the prisoner’s dilemma?

In China, some churches are registered and some are unregistered. That bifurcation is arguably good at this point, as it provides ways to follow Christ for people with different views of the government. But if the state began cracking down harshly on house churches, continued subservience to the government by registered churches could isolate and worsen the plight of their unregistered fellow Christians.

In Venezuela, the oppressive government of Nicolas Maduro gives grants to churches that remain submissive to the government. Accepting these grants may help a particular congregation, but at the expense of abandoning Christian solidarity with others undergoing persecution by the government.

Church growth efforts can mimic the prisoner’s dilemma too, if we seek to build our own congregation or mission project by criticizing and poaching others rather than making overall strengthening of the body of Christ our priority.

If this dynamic sounds familiar to you, please share your examples for a future reader response section. Have a great week!