Characterizing the fundamental social handicap in autism.

The social impairments of autism, which are especially salient in autism of the Asperger type, have been attributed to a failure of affective processing, and more recently to a failure to develop a "theory of mind". Recent research evidence bearing on these theories is reviewed and a new hypothesis is put forward, based on research in progress, which posits a developmentally earlier abnormality of the "social gaze response": the inherent tendency of the normal infant to focus gaze and attention on social cues and, later, on objects in the environment as indicated by the gesture of gaze of others. Weakness or absence of the social gaze response is enough, it is argued, to account for many of the typical symptoms of autism, including the failure to acquire a theory of mind.