Dissociation of two kinds of source attributions.

We examined the relationship between two different source attribution errors. One error found primarily in the cognitive psychology literature is the belief that one is an author of an idea when one is not. The other error, reported in the social psychology literature, occurs when people overestimate how long they have known an idea. Although somewhat different, both errors are a form of misappropriation of ideas to oneself. We investigated both attributions and found that when participants performed a more elaborate encoding task, erroneous claims of authorship were reduced but length-of-knowing judgments increased. The results are discussed in terms of the cognitive processing that is likely to give rise to each source attribution.