Superrationality

In economics and game theory, a participant has superrationality (or renormalized rationality) if the participant is perfectly rational (maximizes utility) but assumes that all other participants are also superrational, and that any superrational participant will always come up with the same strategy as any other superrational participant when facing the same problem. Applying this definition, a superrational player in a two player prisoner's dilemma will cooperate while a rationally self-interested player would defect.

This decision rule is not a mainstream model in game theory and was suggested by Douglas Hofstadter in his article, series, and book Metamagical Themas as an alternative type of rational decision making different from the widely accepted game-theoretic one. Hofstadter provided this definition: "Superrational thinkers, by recursive definition, include in their calculations the fact that they are in a group of superrational thinkers."

Unlike the supposed "reciprocating human", the superrational thinker will not always play the equilibrium that maximizes the total social utility and is thus not a philanthropist.