How Rational is Popper's Rationality Principle?

This paper shows the relevance of Popper's Rationality Principle (RP) for the appraisal of the impressive mass work emerging, in recent years, in the fields of rationality, learning, evolutionary games and behavioral economic theory. In contradistinction to the well-known rigid criteria of the falsacionist Popper, the RP covers a large and diverse spectrum of behaviors compatible with the minimal idea of 'acting in accordance with the situation'. Its relevance to understand the formation of social conventions or how agents learn 'to play Nash equilibrium' is argued at length here