Paranoid schizophrenics, non-paranoid schizophrenics and normals were assessed on tasks designed to demonstrate their tendency to perceive illusory correlations. It was hypothesized that paranoids would show stronger illusory correlations than normals due to the predominance of their schemata when processing information, and that non-paranoids would show weaker correlations than normals because of their impaired ability to establish conceptual categories. Results were broadly consistent with predictions.