Prisoner's dilemma

The prisoner's dilemma is a standard example of a game analyzed in game theory that shows why two completely "rational" individuals might not cooperate, even if it appears that it is in their best interests to do so. It was originally framed by Merrill Flood and Melvin Dresher working at RAND in 1950. Albert W. Tucker formalized the game with prison sentence rewards and named it, "prisoner's dilemma."

Quotes

• The two-person iterated Prisoner’s Dilemma is the E. coli of the social sciences, allowing a very large variety of studies to be undertaken in a common framework.
  • Robert Axelrod, The Complexity of Cooperation (1997), Preface

• I will argue that group selection is important, contrary to the prevailing dogma among biologists.  If group selection is important, Prisoner's Dilemma is not a good model for evolution. It is still an amusing toy for mathematicians and game-theorists to play with.
  • Freeman Dyson, "The Prisoner's Dilemma: Is it a model for the evolution of cooperation in the real world, or is it only a mathematical toy?" (2012).

• I do not believe the fashionable dogma.  Here is my argument to show that group selection is important.  Imagine Alice and Bob to be two dodoes on the island of Mauritius before the arrival of human predators.  Alice has superior individual fitness and has produced many grandchildren.  Bob is individually unfit and unfertile.  Then the predators arrive with their guns and massacre the progeny indiscriminately.  The fitness of Alice and Bob is reduced to zero because their species made a bad choice long ago, putting on weight and forgetting how to fly.  I do not take the Prisoner’s Dilemma seriously as a model of evolution of cooperation, because I consider it likely that groups lacking cooperation are like dodoes, losing the battle for survival collectively rather than individually.
  • Freeman Dyson, "The Prisoner's Dilemma" (2012).