The formation of social preferences: some lessons from psychology and biology

The goal of this paper is to draw some lessons for economic theory from research in psychology, social psychology and, more briefly, in biology, which purports to explain the «formation» of social preferences. We elicit the basic mechanisms whereby a variety of social preferences are determined in a variety of social contexts. Biological mechanisms, cultural transmission, learning, and the formation of cognitive and emotional capacities shape social preferences in the long or very long run. In the short run, the built-in capacities are utilized by individuals to construct their own context-dependent social preferences. The full development of social preferences requires consciousness of the individual's similarities and differences with others, and therefore knowledge of self and others. A wide variety of context-dependent social preferences can be generated by just three cognitive processes: identification of self with known others, projection of known self onto partially unknown others, and categorization of others by similarity with self. The self can project onto similar others but is unable to do so onto dissimilar others. The more can the self identify with, or project onto, an other the more generous she will be. Thus the self will find it easier to internalize and predict the behaviour of an in-group than an out-group and will generally like to interact more with the former than with the latter. The main social motivations can be simply organized by reference to social norms of justice of fairness that lead to reciprocal behaviour, some kind of self-anchored altruism that provokes in-group favouritism, and social drives which determine an immediate emotional response to an experienced event like hurting a norm's violator or helping an other in need