Game theory, behavior, and the paradox of the Prisoner's Dilemma: three solutions

The Prisoners' Dilemma game is a deceptively simple 2 x 2 matrix game which can be used to illustrate the value and the limitations of game theoretic thinking. Its simplicity makes it most attractive as a paradigm to explain human behavior. Furthermore it is easy to experiment with. The very simplicity of this game is a danger. Analogies between it and human affairs are best employed to study their inadequacies and to pinpoint what has been left out rather than to claim how much of the world can be packed into a 2 x 2 matrix.