The typical prisoner’s dilemma is set up where cooperation and trust wins and blind pursuit of self-interest loses.
Suppose two individuals, A and B, have been arrested on the suspicion that they have committed a serious crime. Although they are guilty, there is not enough evidence for conviction of the serious crime but enough for a lesser one. The accused are separated and not allowed to communicate with each other. The district attorney wants them to confess to the crime that they have committed. Should A and/or B confess or not confess to the district attorney the crimes they have committed
1. If both A and B confess, they will be convicted of the serious offense, but their sentence will be reduced from 10 to 6 years.
2. If A does not confess, but B confesses, A will get a maximum sentence of 10 years, and B will get the minimum sentence of 4 years.
3. If A confesses, but B does not confess, A will get a reduced sentence of 4 years, and B will get the maximum sentence of 10 years.
4. If both A and B hold out and do not confess, they can be convicted only for the lesser offense and sentenced for 2 years.
The matrix presents a dilemma for the prisoners: If each tries to maximize his own gain, he will confess and implicate his confederate. If they both do that they will be worse off than if they both held out and did not confess. Yet, if each one considers what he should do, regardless of what the other does, he should confess. Thus, if B confesses, A is better off if he too confesses; if B does not confess, A is again better off if he confesses. The dilemma can be resolved only if the prisoners trust each other, follow a criminal code of never cooperating with the police, or identify with each other to such a degree that the confederate’s payoff in some degree is his own.
