Keywords: cooperation, wisdom, prisoner’s dilemma, defecting, decision-making
The prisoner’s dilemma game has become a standard tool for examining cooperation and decision making in humans.
The prisoner’s dilemma
Two members of a criminal gang are arrested and imprisoned. Each prisoner is in solitary confinement with no means of communicating with the other. The prosecutors lack sufficient evidence to convict the pair for the main crime they are suspected of, but they do have enough to convict both on a lesser charge.
Simultaneously, the prosecutors offer each prisoner a bargain. Each prisoner is given the opportunity either to betray the other by testifying that the other committed the crime, or to cooperate with the other by remaining silent. The offer is:
If A and B each betray each other, each of them serves two years in prison.
If A betrays B but B remains silent, A will be set free and B will serve three years in prison (and vice versa).
If A and B both remain silent, both of them will only serve one year in prison (on the lesser charge).
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