Short unstructured social interactions between a volunteer interviewer, an adult with autism of Asperger type, and a control subject with a schizoid personality disorder were video-recorded. Asperger subjects tended to look less at the other person, to make more self-stimulatory gestures, and to look at the interviewer significantly less than normal subjects, and substantially less than schizoid subjects, during the periods when the interviewer was vocalizing although there were no such differences when the interviewer was listening. We suggest that the gaze avoidance of autism may in actuality be a lack of expected gaze (e.g., gaze when the other person is talking) rather than an absolute avoidance, and suggest that a lifelong absence of gaze response to social cues including speech could explain a number of the developmental features of autism including lack of joint attention with others, lack of understanding and affective response to others, and poor discrimination of facial expressions.