A standardised clinical examination which focused on neurological soft signs (NSS) was used by a neurologist blind to diagnosis to assess the presence of neurological soft signs. A comparison of NSS score was made among three groups of subjects consisting of 58 DSM-III schizophrenics, 31 of their healthy first-degree relatives and 38 normal controls. The schizophrenic group had significantly higher NSS total scores than normal controls but did not differ significantly from their first-degree relatives' group. The relatives' group showed higher NSS total scores than did normal controls although to a lesser extent than schizophrenics.

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Background: Deficits in theory of mind have frequently been observed in people affected by illnesses characterized by disrupted social behaviour like autism and psychoses. In schizophrenia, a pragmatic deficit in expressive language can also be observed. The present study was designed in order to assess the suitability of theory of mind and pragmatic conversation abilities as possible cognitive endophenotypes of schizophrenia. Methods: First- and second-order false belief tasks and pragmatic deficits in expressive language were examined in 38 patients with schizophrenia, in 34 non-psychotic relatives and in 44 healthy controls. An extensive clinical and neuropsychological assessment was also conducted. Results: Schizophrenic people and their first-degree relatives performedworse than the normal control subjects in false belief and pragmatic conversation tasks. General cognitive ability and neuropsychological measures of executive functions were not related to social cognition tasks. Conclusions: Theory of mind disorders and failing to understand the gricean conversational maxims are associated with schizophrenia liability.

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