Several scales are described for measuring aspects of eccentricity and social isolation; in particular, for assessing schizoid and schizotypal personality and for rating abnormal non-verbal expression. The latter is shown to be reliable, and the former to have a measure of validity. There was an association between schizoid personality traits and abnormalities of speech and non-verbal expression. However, abnormal non-verbal expression, but not schizoid personality traits or DSM–III schizotypal personality disorder, was particularly likely to occur in those subjects who had evidence of neurological deficit, and childhood symptoms indicative of developmental disorder. Abnormal non-verbal expression, but not personality disorder, was also associated with other characteristic features of Asperger's syndrome, such as unusual, 'special’ interests. It is suggested that Asperger's syndrome is a distinct syndrome from either schizoid or schizotypal personality disorder, but may be a risk factor for the development of schizoid personality disorder.