Causal processing and schizotypy

Schlottmann and Shanks (1992), using a task based on Michotte (1963) launch events, demonstrated a dissociation in the use of contingency and contiguity cues in making causal decisions; specifically that judgements of necessity showed a greater influence of contingency cues, while perceived causality ratings were influenced solely by contiguity cues. The present study used the same paradigm to test a prediction derived from Hemsley (1994); that schizophrenic subjects, and, following a dimensional approach (Claridge, 1987), highly schizotypal controls, will rely more on moment-by-moment perceptions (contiguity) than learnt regularity (contingency) in causal processing and that this would be manifested as a reduced influence of contingency compared to contiguity (compared to subjects low in schizotypy) on judged necessity ratings. Thirty nonpsychiatric Ss grouped as high or low schizotypy according to a median split of scores on the O–LIFE questionnaire (Mason, Claridge and Jackson, 1995) completed the task. Performance was not in line with prediction, but schizotypy did appear to influence performance on perceived causality ratings; a speculative explanation for this and suggestions for future research are discussed.