JB is a 31-year-old man who has been described as having borderline intelligence/mild learning disability. (His overall IQ is difficult to assess, but has been estimated as around 70, or above.) Over the period of his childhood, he was assessed by numerous child psychiatrists and psychologists, all of whom agreed that he had a diagnosis of autism or some related pervasive developmental disorder, although his presentation was always described as ‘atypical’. The cause of his developmental disorder has never been established, despite the conventional extensive biological, genetic and other physical investigations (Gillberg, 1990).