Expectation-based and data-based illusory correlation: the effects of confirming versus disconfirming evidence

Examined the effects of expectations and stimulus information on the perception of illusory correlation. Expectation was manipulated by telling 154 psychology students that group B behaved more negatively than group A vs by providing no expectation. Ss were also provided with information contained in a statement-rating task that allowed for the confirmation and disconfirmation of the prior expectations. Ss then rated the desirability of these behaviors and performed the standard illusory correlation tasks. In the absence of prior expectations, completing the rating task before the illusory correlation tasks produced stronger illusory correlation than the reverse order. However, in the presence of prior expectations, the rating task undermined illusory correlation, because the information obtained in this task disconfirmed prior expectations."