Robert Axelrod

"The theory of biological evolution is based on the struggle for life and the survival of the fittest. Yet cooperation is common between members of the same species and even between members of differen…"

"In fact, in the Prisoner's Dilemma, the strategy that works best depends directly on what strategy the other player is using and, in particular, on whether this strategy leaves room for the developmen…"

"Four factors are examined which can give rise to interesting types of social structure: labels, reputation, regulation, and territoriality. A label is a fixed characteristic of a player, such as sex o…"

"Thus cooperation can emerge even in a world of unconditional defection. The development cannot take place if it is tried only by scattered individuals who have no chance to interact with each other. B…"

"Just as important as getting cooperation started were the conditions that allowed it to be sustainable. The strategies that could sustain mutual cooperation were the ones which were provocable."

"Proposition 1. If the discount parameter, w, is sufficiently high, there is no best strategy independent of the strategy used by the other player."

"Tournament studies, ecological simulation, and theoretical analysis demonstrate: A generous version of tit for tat is a highly effective strategy when the players it meets have not adapted to noise; I…"

"Once again, there is an important contrast between a zero-sum game like chess and a non-zero-sum game like the iterated Prisoner's Dilemma. In chess, it is useful to keep the other player guessing abo…"