Razionalità e motivazioni affettive: nuove idee dalla neurobiologia e psichiatria per la teoria economica?

Psychology has recently attracted renewed attention from economists, since the classical theory of rational choice seems unable to explain various “anomalies” usually observed in human behaviour. In the attempt to depart from Homo Economicus and achieve a more realistic representation of human behaviour, ‘behavioural economics’ proposes the conservative integration of the classical theory with inductive hypotheses drawn from psychology. Also ‘bounded rationality economics’ draws from psychology, but to model a new concept of rationality. Both proposals have yielded several results, but the research is still in a fluid state. This paper takes the research a step further, because it explores the literature in neurobiology and psychiatry, besides that in psychology. The intuition is that these disciplines suggest a more radical reconsideration of the role of rationality in human behaviour because of other fundamental motivations. The results of the literature in these disciplines are not well established, and they will therefore be organised as working hypotheses of specific interest to economists. A selection of the literature has been inevitable, since some results are still debated in the specialised journals, and different schools of thought persist. On the basis of some authoritative works in neurobiology, complemented by various strands of analysis in psychology, it can be argued that human behaviour is largely explained by affective motivations arising from the mental image of our bodily reactions (emotions) to perceptions of external or internal stimuli, and which are largely unconscious. First, affective motivations are necessary for rational thought and decision-making, since they provide the information with which to define “preferences”, and drive for decisions. Secondly, they constitute autonomous motive forces for hedonistic behaviour which are different from the more basic instinctive reactions, and which may instead complement rational thought in many domains of human behaviour. Thirdly, they crucially contribute to forming an individual’s specific identity as a state variable in the choice. A self-confident identity both relies more upon, and is strengthened by, the affective motivations. If identity neglects affective motivations, the individual is left to decide mainly on impersonal rational bases, and under the influence of instinctual drives. This latter case is assumed as the standard problematic case by behavioural economics, as exemplified by addiction. A recent strand of analysis in psychology further shows a striking result for the economists: that motivation for wealth and financial success leads the individuals to less well-being than motivation for self-actualisation and interpersonal relationships, that is, affective motivations. This literature in neurobiology and psychology, however, does not adequately answer the question of how affective motivations and rationality can develop in a balanced way throughout the human life, rather than leading to materialism and addiction. The answer can be found in psychiatry. From birth and infancy onwards, individuals need not only material things but also, and especially, human relationships. In fact, if these are not satisfactory, the attachment will be diverted to things, so that affects are ignored and a vicious circle triggered. Motivations become both more rational to buy things and more instinctual to need them, while the unconscious ability to enjoy human relationships diminishes. Unfortunately, economics usually takes human relationships as a mean and things as an end, rather than the other way around.