Dalla matematizzazione dell'economia neoclassica alla fisica quantistica nei processi cognitivi. Certezze e crisi dell’idea di razionalità: dall’homo oeconomicus ai modelli quantistici della mente

The origin of the idea of rationality as a fundamental model of human behaviour (the concept of homo oeconomicus) that was introduced during the neoclassical revolution in economics and that implied the mathematization of economics thereby adopting the mathematical scheme of and borrowing some fundamental conception from classical mechanics, as well as the crisis of this rationality model that followed in the latest decades are here discussed. The origin of the least action principle in 18th century is first described. The least action principle was the basis that lead to the development of Lagrangean dynamics in classical mechanics that, on its turn, entered economics in 19th century as a fundamental method to describe the behaviour of a postulated rational agent and was the basis for the development of mainstream economics in 20th century. The epistemologically unjustified transfer of concepts from mechanics, in particular in Walras’ work, is stressed. In the second half of 20th century experimental psychology slowly entered economics and several paradoxes in the real agents’ choices were shown giving strong evidence of rationality’s axioms violation in the real behaviour of people. By mid-20th century, quantum mechanics had already developed a highly effective mathematical apparatus to describe the wave-particle behaviour of quantum objects and in particular the phenomenon of probability interference that is clearly shown in the double-slit experiment with single electrons, as well as with photons. Probability interference is peculiar to quantum mechanics and is extraneous to the Kolmogorov axiomatic theory of classical probability. The recent idea of applying the quantum mechanics concepts and formalism, including quantum probability interference and superposition of states, to the description of mental processes is discussed. The aim of this new field of research, which is developing along the lines of the centuries-old question of the mind-body relation, is to create a general framework where cognition might be modeled. Quantum cognition is therefore introduced as a possible answer to the rationality violation paradoxes shown by experiments on ambiguous figures recognition and on the effects brought about by conjunction and disjunction of concepts.