The Prisoner's Dilemma was created in 1952. It states that two individuals who are imprisoned and both completely rational actors will not cooperate, even if it is in their best interest. In the example, both prisoners are in solitary confinement and may not communicate. There is not enough evidence to get them on the major charge but enough to get each on minor charges. They are given a deal to either testify and betray each other or remain silent and cooperate with one another. Betraying each other gets them both two years. If one betrays the other but the other stays silent, the one who stays silent gets three years while the snitch goes free. If both remain silent, they'll both only serve a year. The idea is that both will betray each other because of the purely rational gain of freedom rather than cooperate even though this dual betrayal ends in a worse outcome. That is the point: that cooperative behavior is not the usual outcome when the actors are purely rational.