Theory of Mind, Weak Central Coherence and executive dysfunction, were investigated as a function of behavioural markers of autism. This was irrespective of the presence or absence of a diagnosis of an autistic spectrum disorder. Sixty young people completed the Social Communication Questionnaire (SCQ), false belief tests, the block design test, viewed visual illusions and an ambiguous figure. A logistic regression was performed and it was found that Theory of Mind, central coherence and ambiguous figure variables significantly contributed to prediction of behavioural markers of autism. These findings provide support for the continuum hypothesis of autism. That is, mild autistic behavioural traits are distributed through the population and these behavioural traits may have the same underlying cognitive determinants as autistic disorder.

Difficulties experienced by some young people with mild and borderline intellectual disability are associated with enhanced liability to schizophrenia. Clinical methods can both identify those with this extended phenotype and predict those in whom psychosis will occur.

Cognitive performance and the relationship between theory of mind (TOM), weak central coherence and executive function were investigated in a cohort of young people with additional learning needs. Participants were categorized by social communication questionnaire score into groups of 10 individuals within the autistic spectrum disorder (ASD) range, 14 within the pervasive developmental disorder range and 18 with few autistic traits. The ASD group were significantly poorer than the other groups on a test of cognitive flexibility. In the ASD group only, there was a strong relationship between executive performance and TOM which remained after controlling for IQ. Our findings suggest that the relationship between cognitive traits may more reliably distinguish autism than the presence of individual deficits alone.