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.