In cause-outcome contingency judgement tasks, judgements often reflect the actual contingency but are also influenced by the overall probability of the outcome, P(O). Action-outcome instrumental learning tasks can foster a pattern in which judgements of positive contingencies become less positive as P(O) increases. Variable contiguity between the action and the outcome may produce this bias. Experiment 1 recorded judgements of positive contingencies that were largely uninfluenced by P(O) usin...