Many of us are familiar with the quotation, \u201cRepeat a lie often enough and people will eventually come to believe it.\u201d<\/p>\n\n\n\n

Not ironically, the adage \u2014 often attributed to the infamous Nazi Joseph Goebbels \u2014 is true and has been validated by decades of research on what psychology calls the \u201cillusory truth effect.\u201d First described in a 1977 study by Temple University psychologist Dr. Lynn Hasher and her colleagues, the illusory truth effect occurs when repeating a statement increases the belief that it\u2019s true even when the statement is actually false.^{1<\/sup><\/p>\n\n\n\n}

Subsequent research has expanded what we know about the illusory truth effect. For example, the effect doesn\u2019t only occur through repetition but can happen through any process that increases familiarity with a statement or the ease by which it\u2019s processed by the brain (what psychologists in this context refer to as a statement\u2019s \u201cfluency\u201d). For example, the perceived truth of written statements can be increased by presenting them in bold, high-contrast fonts^{2<\/sup>\u00a0or when aphorisms are expressed as a rhyme.3<\/sup><\/p>\n\n\n\n}

According to a 2010 meta-analytic review of the truth effect (which applies to both true and false statements),^{4<\/sup> while the perceived credibility of a statement\u2019s source increases perceptions of truth as we might expect, the truth effect persists even when sources are thought to be unreliable and especially when the source of the statement is unclear. In other words, while we typically evaluate a statement\u2019s truth based on the trustworthiness of the source, repeated exposure to both information and misinformation increases the sense that it\u2019s true, regardless of the source\u2019s credibility.<\/p>\n\n\n\n}

The illusory truth effect tends to be strongest when statements are related to a subject about which we believe ourselves to be knowledgeable,^{5<\/sup> and when statements are ambiguous such that they aren\u2019t obviously true or false at first glance.4 <\/sup>It can also occur with statements (and newspaper headlines) that are framed as questions (e.g. \u201cIs President Obama a Muslim?\u201d), something called the \u201cinnuendo effect.”6<\/sup><\/p>\n\n\n\n}

References<\/p>\n\n\n\n

1. Hasher L, Goldstein D, Topping T. Frequency and the conference of referential validity. Journal of Verbal Learning and Verbal Behavior<\/em> 1977; 16:107-112.<\/p>\n\n\n\n

2. Reber R, Schwarz N. Effects of perceptual fluency on judgments of truth. Consciousness and Cognition: An International Journal<\/em> 1999; 8:338-342.<\/p>\n\n\n\n

3. McGlone MS, Tofighbakhsh J. Birds of a feather flock conjointly (?): Rhyme as reason in aphorisms. Psychological Science<\/em> 2000; 11:424-428.<\/p>\n\n\n\n

4. Dechene A, Stahl C, Hansen J, Wanke M. The truth about the truth: a meta-analytic review of the truth effect. Personality and Social Psychology Review <\/em>2919; 14:238-257.<\/p>\n\n\n\n

5. Arkes HR, Hackett C, Boehm L. The generality of the relation between familiarity and judged validity. Journal of Behavioral Decision Making<\/em> 1989; 2:81-94.<\/p>\n\n\n\n

6. Wegner DM, Wenzlaff R, Kerker RM, Beattie AE. Incrimination through innuendo: can media questions become public answers? Journal of Personality and Social Psychology<\/em> 1981; 40:5:822-832.<\/p>\n\n\n\n

7. Fazio LK, Brashier NM, Payne BK, Marsh EJ. Knowledge does not protect against illusory truth. Journal of Experimental Psychology: General <\/em>2015; 144:993-1002.<\/p>\n\n\n\n

8. Pennycook G, Cannon TD, Rand DG. Prior exposure increases perceived accuracy of fake news. Journal of Experimental Psychology: General<\/em> 2018; 147:1865-1880.<\/p>\n","protected":false},"excerpt":{"rendered":"