RESUMO
Individuals interpret themselves as causal agents when executing an action to achieve an outcome, even when action and outcome are independent. How can illusion of control be managed? Once established, does it decay? This study aimed to analyze the effects of valence, probability of the outcome [p(O)] and probability of the actions performed by the participant [p(A)], on the magnitude of judgments of control and corresponding associative measures (including Rescorla-Wagner's, Probabilistic Contrast, and Cheng's Power Probabilistic Contrast models). A traffic light was presented on a computer screen to 81 participants who tried to control the green or red lights by pressing the spacebar, after instructions describing a productive or a preventive scenario. There were 4 blocks of 50 trials under all of 4 different p(O)s in random order (0.10, 0.30, 0.70, and 0.90). Judgments were assessed in a bidimensional scale. The 2 × 4 × 4 mixed experimental design was analyzed through General Linear Models, including factor group (between-subject valence), and block and p(O) (within subjects). There was a small effect of group and a large and direct effect of p(O) on judgments. Illusion was reported by 66% of the sample and was positive in the productive group. The oscillation of p(O) produced stronger illusions; decreasing p(O)s produced nil or negative illusions. Only Rescorla-Wagner's could model causality properly. The reasons why p(A) and the other models could not generate significant results are discussed. The results help to comprehend the importance of keeping moderate illusions in productive and preventive scenarios.