Illusory Correlations: Explicating and Stimulating Their Apparent and Less Apparent Origins

Subjective correlation judgments that exaggerate or distort the objectively presented contingency between two variables in a series of stimulus observations are usually referred to as illusory correlations (IC). An empirical review reveals many different variants of ICs in diverse paradigms. Two basic Gestalt principles, consistency and distinctiveness, are used in most theoretical explanations. Consistency accounts for ICs between meaningfully related attributes, whereas the notion of distinctiveness explains ICs between outstanding, salient stimulus aspects. A theoretical conflict arises from the opposite processing implications of these two theory heuristics. The consistency principle implies a processing advantage for expected stimuli, whereas distinctiveness accounts assume enhanced processing of unexpected events. This apparent conflict is resolved, and an integrative account of most types of Ics is given using a simple connectionist model (BIAS) of correlation assessment. Within this framework, different origins of ICs can be distinguished precisely and previously neglected factors can be identified. An important theoretical insight is that no biased processes are necessary to explain biased correlation judgments.