In the present study, two cognitive phenomena until now treated apart were compared to each other: hindsight bias and misinformation effect. Both phenomena result from the same basic retroactive-interference procedure focussing on how memory of originally encoded material is distorted by the encoding of subsequent, conflicting information. The results showed that subjects' recollections of the original information were similarly distorted under both conditions, that is, the amount of hindsight bias was as large as the misinformation effect. More fine-grained analyses, however, revealed important differences. With the additional results of a probability mixture model it was found that only hindsight subjects suffered from memory impairment and that, moreover, their recollections included genuine blends. The misinformation effect, on the other hand, turned out to be an artifact of averaging across two different sets of recollections. These results represent compelling data with respect to the ongoing discussion about the existence of genuine memory blends.

In hindsight, people often claim to have known more in foresight than they actually did. For example, the confidence for one of several possible outcomes is larger when it is known that this particular outcome occurred. A widespread explanation of hindsight bias assumes that the feedback serves as an anchor. How precisely this anchor takes effect and why it leads to a bias towards the anchor value has not been satisfactorily answered yet. One possible mechanism to explain hindsight bias assumes that the encoding of the feedback leads to a selective activation of the item-specific knowledge base. As a result, specific information units are strengthened and are thus more likely to be recalled when a person tries to reconstruct his or her original judgment. We tested the effect of selective activation in two hindsight experiments. The results showed a clear hindsight bias in that the recalled confidence ratings were distorted towards the feedback. Moreover, the consequences of selective activation were evident in that more information favoring the feedback was recalled.