Illusory truth effect
The Illusory Truth Effect (also known as the truth effect or the illusion-of-truth effect) is the tendency to believe information to be correct because we are exposed to it more often. It was first discovered in 1977 at Villanova University and Temple University[1]. We see some misconceptions or exaggerations frequently in our daily lives, and thus have a tendency to believe them to be true because of our recurrent exposure.
History
The effect was first named and defined following the results in a study from 1977.[1] Participants in it were given a list of 60 factoids which were plausible, but they most likely did not know. It consisted of statements like "The first air force base was launched in New Mexico.", "Large migration of Chinese railroad workers began in the 1880s." or "Basketball became an olympic discipline in 1925." They had to grade their belief that a statement was true on a scale from one to seven.
This was repeated in three occasions with two weeks between each. Twenty of the statements (one third) remained throughout all occasions. The rest of the statements were new. Respondents graded for the repeated statements higher in later sessions: 4.2 in the first session, 4.6 in the second session and 4.7 in the last session. However, the grading for the rest of the statements showed no discernible pattern.
Experimental Evidence
An experiment conducted by Lisa Fazio of Vanderbilt University illustrated the illusory truth effect. A group of undergraduate students were asked to read through a list of sentences, some of which were blatantly true, some of which were blatantly false, and others which were more complicated. For example: “North America is a continent.” (True.) “A clementine is a not fully grown orange.” (False.) “Sydney is the capital of Australia.” (False, but maybe not so obvious, depending on one’s knowledge of world capitals.) After, students were given another set of statements, but they were asked to rank each statement on a scale of 1 to 6, with 1 meaning definitely false and 6 meaning definitely true. Finally, the participants answered multiple-choice questions that corresponded to the previous statements they had just read[2].
Results from this study revealed that the ease with which people comprehend statements, also known as processing fluency, underlies the illusory truth effect. The use of repetition makes statements easier to process, compared to new statements, which leads people to the false conclusion that the repeated statements are more truthful[2].
Effect on Young vs. Old
The illusory truth effect has diverse effects on young versus old people. Older individuals are less likely to be subject to the illusory truth effect because they have impairments of experiential memory, but not in knowledge memory. Therefore, older adults will be less likely to believe a false knowledge-based fact than would a younger individual, because older adults tend to have more stored knowledge.[3]
Criminal Justice System
Eyewitness Testimony
The Illusory Truth Effect plays into false accusations. Eyewitnesses are frequently shown line-ups when they witness crimes, however, before the physical lineup they are usually exposed to picture lineups. The more frequently that you are shown someone’s face the more likely to you are to pick them out – so over-exposure to suspects could lead to false accusations and false convictions. [4]
Courtroom Settings
Illusory Truth Effect also appears in the criminal justice system in the courtroom. In courtrooms lawyers sometimes say things that they aren’t meant to, and if the opposing side objects to this then the judge can strike it from the record and tell the jurors to forget what they heard. However, it might be easy to erase a sentence from a transcript, but not so easy to erase if from a jurors mind. Thus, sometimes, the opposing side will not object to leading statements so as to not call the jurors attention to it. They hope that the jurors will skate over the unwanted comment, and not dwell on it during deliberation. If the defense objects to something the prosecutors say then this may lead to an illusory truth effect – causing the jurors to remember this fact more than others and thus consider it more highly when deciding on a verdict. [4]
References
- ^ a b Hasher, Goldstein, and Toppino (1977)
- ^ a b "Even People Who Know Better Fall for Lies If They Hear Them Enough". Science of Us. Retrieved 2016-04-22.
- ^ Gallo, David (2013-05-13). Associative Illusions of Memory: False Memory Research in DRM and Related Tasks. Psychology Press. ISBN 1134606761.
- ^ a b Bless, Herbert; Forgas, Joseph P. (2000-01-01). The Message Within: The Role of Subjective Experience in Social Cognition and Behavior. Psychology Press. ISBN 9781841690209.