The ‘‘shared manifold’’ hypothesis: from mirror neurons to empathy

We are social animals. We share this feature with many other species. A complexity and sophistication that we do not observe among ants, bees or wolves, however, characteristically define the social life of primates. This complexity and sophistication is epitomized at its highest level by the social rules our conduct in everyday life is supposed to comply with. Living in a complex society requires individuals to develop cognitive skills enabling them to cope with other individuals’ actions, by recognizing them, understanding them, and reacting appropriately to them. No one doubts that the extant primate ancestors of ours, monkeys and apes, who indeed also live in complex, hierarchically organized societies, are perfectly able to cope with their own social rules. Nevertheless, it is commonly argued that to achieve that goal non-human primates simply rely on behaviour observation. Animals do not represent rules in their minds, and they do not engage in any inference-based reasoning. Accordingly, what non-human primates are lacking would sharply define what is considered to be uniquely human: truly cognitive states, such as intentions, desires and beliefs. In our daily life we are constantly exposed to the actions of the individuals inhabiting our social world. We are not only able to describe these actions, to understand their content, and predict their consequences, but we can also attribute intentions to the agents of the same actions. We can immediately tell whether a given observed act or behaviour is the result of a purposeful attitude or rather the unpredicted consequence of some accidental event, totally unrelated to the agent’s will. In other words, we are able to understand the behaviour of others in terms of their mental states. I will designate this ability as mind-reading. How do we ‘read’ intentions in the mind of other individuals? A common view maintains that all normal humans develop the capacity to represent mental states in others by means of a conceptual system, commonly designated as ‘Theory of Mind’ (TOM, see Premack and Woodruff, 1978). My initial scope will be limited: starting from a neurobiological standpoint, I will analyse how actions are possibly represented and understood. The main aim of my