Gabriela Airenti

In recent years two trends of research, previously separated have converged on a common topic. On one side there is the work of developmental psychologists interested in explaining how young humans develop an attitude toward intersubjectivity. On the other side there is the work of the researchers who try to understand what makes the difference between humans and nonhuman primates.

This turn of research is due to the work of Tomasello and his collaborators who, after years of investigation with young children and chimpanzees have come to the conclusion that what makes the difference between human and nonhuman primates is precisely the attitude towards shared action which, according to them is typically human (Tomasello and Racoczy, 2003; Tomasello et al., 2005). It must be noted that this result due to years of experimental studies corroborates what in a theoretical way had already been stated by Premack and Premack (1994) who considered sharedness the feature that makes the distinction between humans and other primates as well as the basis for cultural transmission.

To clarify what lies behind the concept of sharedness it is useful to reconstruct how Tomasello and his collaborators have “discovered” shared intentionality. In their quest of what makes the difference between human and nonhuman primates their first candidate has been intentionality. The main hypothesis at that time was that the crucial point is the link between imitation and intentional action. Children since nine months have a comprehension of others as intentional actors. This is at the basis of human cultural transmission from one generation to the other by the so-called ratchet effect. The fact that children since a precocious age are able to understand others as intentional agents allows them to perform imitative learning both regarding object-directed actions and the use of communicative symbols. To see the other as an intentional agent is the first step in the development of the concept of person whose successive developments will be to see others as mental agents and then as reflexive agents (Tomasello, Kruger and Ratner, 1993; Tomasello, 1999). Primates do not acquire the concept of person as an intentional agent and do not perform imitation. This does not allow the transmission of knowledge that is constitutive of societies.