RATING CAUSAL RELATIONS - ROLE OF PROBABILITY IN JUDGMENTS OF RESPONSE OUTCOME CONTINGENCY

We investigated the possible role of the conditional probabilities of an outcome given a response P(O\R) and of an outcome given the absence of a response P(O\NoR) in mediating college students' judgments of response-outcome contingency. A total of 150 subjects in three experiments was asked to describe the effect that telegraph key tapping had on the brief illumination of a lamp. Subjects' ratings along a prevent-cause scale closely approximated the scheduled contingencies between response (R = key tap) and outcome (O = lamp illumination), as measured by the delta coefficient DELTAP = P(O\R) - P(O\NoR) (Experiments 1 and 3). Subjects also sensitively rated the conditional probabilities of an outcome when they tapped the key and when they refrained from doing so (Experiments 2 and 3). Nevertheless, the evidence failed to support the hypothesis that causal ratings were mediated by subjective judgments of P(O\R) and P(O\NoR) because the errors made in judging the conditional probabilities were not consistent with the errors made judging DELTAP. We suggest that an associative explanation derived from a model devised by R. A. Rescorla and A. R. Wagner (1972) might account for these and other results.