clipped from: en.wikipedia.org The Evolution of Cooperation the title of a 1981 article and a related 1984 book by political science professor Robert Axelrod. The nine-page article, co-written with the late evolutionary biologist William D. Hamilton, has garnered over 8000 citations [1].
The article and book explore the conditions under which fundamentally selfish agents will spontaneously cooperate. To perform this study, Axelrod developed a variation of prisoner's dilemma (PD), involving repeated PD interactions between two players (i.e., strategies written as computer programs) in a computerised tournament. This iterated prisoner's dilemma (IPD) format, he found, tends to offer a long-term incentive for cooperation, even though there is a short-term incentive for defection (the opposite of cooperation).