Memory & Cognition 2005, 33 (3), 418-429 Wishful thinking and source monitoring RUTHANNA GORDON Illinois Institute of Technology, Chicago, Illinois and NANCY FRANKLIN and JENNIFER BECK State University of New York, Stony Brook, New York Memory distortions sometimes serve a purpose: It may be in our interest to misremember some de- tails of an event or to forget others altogether. The present work examines whether a similar phenom- enon occurs for source attribution. Given that the source of a memory provides information about the accuracy of its content, people may be biased toward source attributions that are consistent with de- sired accuracy. In Experiment 1, participants read desirable and undesirable predictions made by sources differing in their a priori reliability and showed a wishful thinking bias—that is, a bias to at- tribute desirable predictions to the reliable source and undesirable predictions to the unreliable source. Experiment 2 showed that this wishful thinking effect depends on retrieval processes. Experiment 3 showed that under some circumstances, wishes concerning one event can produce systematic source memory errors for others. The origin of a message—hence, the origin of one’s to be designed to operate in a sensible manner, by relying memory for it—is often diagnostic of how trustworthy on features with values empirically correlated with the the message’s content is. Information about the reliabil- various candidate sources (e.g., Intraub & Hoffman, 1992; ity of a new car deserves different treatment if read in a Johnson, Foley, & Leach, 1988). Consumer Reports article than if read in a magazine ad However, source monitoring doesn’t always produce ac- or an e-mail from a friend. According to the source mon- curate attributions. Previous work has shown that cases of itoring framework of Johnson and colleagues (Johnson, inaccuracy typically derive from the use of otherwise ap- Hashtroudi, & Lindsay, 1993; Johnson & Raye, 1981), propriate heuristics on anomalous items, such as particu- memories typically are not explicitly tagged with source larly vivid mental images (Johnson & Raye, 1981), invalid information. Rather, cues intrinsic to the memory are schematic information (Sherman & Bessenoff, 1999), or used to reconstruct its source. A memory of reading large guessing errors. Even a system that is designed to make ra- print with lots of exclamation points would, for example, tional decisions sometimes produces errors. The present be a cue that the information about the car had come work addresses one way in which source attributions may from a magazine ad. be influenced by goals other than accuracy. That is, we Several types of cues are used to identify a memory’s have identified a factor that systematically contributes to source, such as perceptual details about the remembered the decision despite being uncorrelated with source. event and information about the cognitive processes that Consider again that you are trying to identify the source occurred when the memory was created (Johnson, Foley, of your memory for information about a car. It may be that Suengas, & Raye, 1988). For the most part, people at- you encountered this information as a casual reader and tribute memories to the source for which the qualities of have no vested interest in the car’s quality. In that case, you the memory’s features (e.g., vividness) are most charac- would probably use intrinsic characteristics of the mem- teristic (see Johnson et al., 1993, for a review). Although ory, as described above, to make a source attribution. source monitoring can occasionally be inaccurate, it seems Alternatively, you may have a vested interest in the car’s quality (for example, because you’ve just bought one). If source monitoring is affected by a wishful think- ing bias, your desire to own a good car might lead you to We thank Glenda Villareal for her help with stimulus construction; attribute the rave review to a reliable source, like a Con- Dan Bashari, Camilla Lo, Frank Yao, Mat Williams, and Sheila Her- manowski for their assistance in running the studies; and Larry Jacoby, sumer Reports article. Similarly, and for the same rea- Colleen Kelley, Richard Gerrig, Susan Brennan, Mara Mather, and three son, you might be biased to attribute a negative review to anonymous reviewers for their helpful comments on this article. Corre- an ad from a competing company. spondence relating to this article can be sent to R. Gordon, Institute of Certainly, accuracy in source monitoring serves peo- Psychology, Illinois Institute of Technology, 3101 South Dearborn, Suite 252, Chicago, IL 60616-3793, or to N. Franklin, Department of ple’s best interests. Even if accurate source decisions Psychology, State University of New York, Stony Brook, NY 11794-2500 have unpleasant implications, they generally can guide (e-mail: [email protected] or [email protected]). our beliefs and actions most appropriately. However, we Copyright 2005 Psychonomic Society, Inc. 418 WISHFUL THINKING AND SOURCE MONITORING 419 have an additional need for beliefs, perceptions, and this possibility is confounded with another: Participants memories that support an optimistic worldview. Unde- may have a source monitoring heuristic suggesting that sirable but accurate judgments serve our need to form a they usually choose the better of two options. Indeed, correct model of the universe, whereas desirable but in- when the choice between options is made by the experi- accurate judgments serve other needs of mental self- menter rather than the participant, the effect disappears preservation. (Mather, Shafir, & Johnson, 2003). A brief look across different literatures on cognition To illustrate the purpose of the present work and its suggests a broad influence of desire on information pro- potential value better, imagine that you are a cancer pa- cessing. Desire can affect what we remember, as with se- tient and that you have read an article in the National En- lective distortions in memory for poor grades (Bahrick, quirer about a new “miracle cure” that eliminates can- Hall, & Berger, 1996) or choice-supportive effects (Del- cers entirely. You wish the story were true, but you know larosa & Bourne, 1984; Greene, 1981; Mather & John- that the Enquirer is an unreliable source. Later, the de- son, 2000; Mather, Shafir, & Johnson, 2000). In both of sire to believe that the story was accurate may cause you these examples, memory is distorted to make it appear to recall the source as the New York Times. It is under- that past performance or judgment was better than it ac- standable that the need for self-protection and for hope tually was (see also Greenwald, 1980; Ross, McFarland, might lead you to this error. Using much less dramatic & Fletcher, 1981). People are also more likely to retrieve scenarios, Experiment 1 sought to create circumstances accurate information when it is consistent with their in which such a bias might emerge. Experiment 2 ex- wishes and less likely when it is not (Woike & Polo, plored possible loci of the effect at encoding and at re- 2001). Desire also extends to cognitive processes other trieval. Once the basic effect was established in Experi- than memory, including perception (Boon & Davies, ments 1 and 2, Experiment 3 tested how indirectly and 1996), likelihood estimation (Perloff & Fetzer, 1986; how broadly wishful thinking may influence memory. Taylor, 1989; Weinstein & Klein, 1996), and judgment (Ditto, Jemmott, & Darley, 1988; see also Kunda, 1990, EXPERIMENT 1 for a review). Establishing the Effect Thus, wishful thinking in its various forms pervades cognition. It is reasonable, then, to wonder whether desire- Experiment 1 tested for a wishful thinking bias by based distortions affect source memory. A small number using two sources of differing accuracy who made pre- of studies point toward such a possibility. Morrison and dictions that were either desirable, undesirable, or neu- Haddock (1997) have shown a bias to attribute negative tral. After a delay, participants attempted to recall the thoughts to an internal source and positive thoughts to source of each prediction. an external source. It may be in our interest to attribute In order to induce participants to wish that one or the negative messages to private thoughts, whereas positive other source had produced the different predictions, but messages may have more ego-boosting value if remem- also in an effort to equate the two in their global degree bered as originating elsewhere (see also Bentall, 1990). of expertise, we used two fictitious psychics as sources. However, this finding could also reflect a rational heuris- We manipulated their reliability, with one having a high tic: Politeness may bias the statements of those around us and the other a low overall hit rate in their predictions. in a positive direction, but no such filter limits our inter- Wishful thinking would be demonstrated if people were nal monologues. biased to attribute desirable predictions to the reliable More support for the role of wishful thinking in source psychic and undesirable predictions to the unreliable monitoring comes from unconscious plagiarism para- psychic, regardless of the actual source. digms. Participants falsely attribute other people’s ideas to themselves under some circumstances (Marsh, Lan- Method dau, & Hicks, 1997), and this error may arise because Participants. Thirty-six undergraduates at SUNY Stony Brook people want to believe that they and not others were the received course research credit or $7 compensation for participat- source of good ideas. A direct test of this hypothesis, ing in a single 1.5-h session. All were fluent speakers of English. however, would require a comparison of source accuracy Materials and Design. An introductory paragraph, read by all between ideas of varying quality, and to our knowledge participants, described one psychic, Anna Ashland, as highly reli- able (80% correct across her predictions) and another psychic, Candy this factor has not been directly manipulated.