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]
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.