Superrationalité

In economics and game theory, a participant is considered to have superrationality (or renormalized rationality) if they have perfect rationality (and thus maximize their 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 the 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. Superrationality is a form of Immanuel Kant's categorical imperative, and is closely related to the concept of Kantian equilibrium proposed by the economist and analytic Marxist John Roemer. Hofstadter provided this definition: "Superrational thinkers, by recursive definition, include in their calculations the fact that they are in a group of superrational thinkers." This is equivalent to reasoning as if everyone in the group obeys Kant's categorical imperative: "one should take those actions and only those actions that one would advocate all others take as well." 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. The idea of superrationality is that two logical thinkers analyzing the same problem will think of the same correct answer. For example, if two people are both good at math and both have been given the same complicated problem to do, both will get the same right answer. In math, knowing that the two answers are going to be the same doesn't change the value of the problem, but in the game theory, knowing that the answer will be the same might change the answer itself.