Evidence for an illusion of causality when using the Implicit Association Test to measure learning

Our ability to detect causal relations and patterns of covariation is easily biased by a number of well-known factors. For example, people tend to overestimate the strength of the relation between a cue and an outcome if the outcome tends to occur very frequently. During the last years, several accounts have attempted to explain the outcome-density bias. On the one hand, dual-process performance accounts propose that biases are not due to the way associations are encoded, but to the higher-order cognitive processes involved in the retrieval and use of this information. In other words, the outcome-density bias is seen as a performance effect, not a learning effect. From this point of view, it is predicted that the outcome-density bias should be absent in any testing procedure that reduces the motivation or opportunity to engage in higher-order cognitive processes. Contrary to this prediction, but consistent with the most common single-process learning accounts, our results show that the outcome-density effect can be detected when the Implicit Association Test is used to measure the strength of cue-outcome associations.