Proceedings of the Annual Meeting of the Cognitive Science Society

The illusory causation effect describes the tendency to judge an unrelated cue and outcome to be causally related. The standard procedure for assessing the illusion is based on the implicit assumptions that participants start as naïve observers with no prior beliefs about the likely relationship between the cue and outcome, and that learning can be adequately captured as a point-estimate causal rating after null contingency training. Here, we use a novel distributional measure to assess participants’ beliefs over a range of causal relationships prior to, as well as after, exposure to non-contingent cues and outcomes. Across two experiments with different causal scenarios and 50% cue and outcome density, we show that participants have an initial bias towards expecting a causal relationship between the cue and outcome, and that this bias is mostly corrected after exposure to the null contingency. We conclude that distributional measures of causal beliefs can offer novel insights in understanding the illusory causation effect.