What is "superrationality"

n. A kind of rational decision-making, different from the widely-accepted game-theoretical one. A player whose opponent is also superrational will cooperate in the (w: Prisoner's dilemma) problem, whereas a game-theoretically rational player will defect.

In economics and game theory, a participant is considered to have superrationality (or renormalized rationality) if they have perfect rationality (and thus maximize their own utility) but assume that all other players are superrational too and that a superrational individual will always come up with the same strategy as any other superrational thinker when facing the same problem. Applying this definition, a superrational player playing against a superrational opponent in a prisoner's dilemma will cooperate while a rationally self-interested player would defect.

This decision rule is not a mainstream model within 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.

Note that contrary to the Homo reciprocan, the superrational thinker will not always play the equilibrium that maximizes the total social utility, and is thus not a philanthropist.