Special Coverage

Perceived Truth as a Function of the Number and Spacing of Repetitions (SYM10)

Sarah Barber (Georgia State University)

Summary by Taylor Curley, Digital Content Associate Editor

A Roadmap for Misinformation and Perceived Truth

All misinformation attempts – from schoolyard rumors to political fodder – rely on a set of statements being perceived as true, regardless of their actual truth. Previous research shows that repeating statements increases their judged “truthiness” (as Stephen Colbert famously said). These findings are limited to a few repetitions. Whether judgments are strengthened over time is an open question.  

Across three experiments, Sarah Barber measured the effects of repetition and spacing of statements on truthiness to provide a roadmap for the changing perception of truth.

Lesson 1: Repeat Each Statement 9 Times

In Experiments 1 and 2, participants experienced different numbers of repetitions for a given set of statements, ranging from no to 27 repetitions. One week later, they rated the truth of the statements. The aggregated ratings, in the plot below, show that perceived truth increases in a curvilinear fashion over repetitions but plateau at around nine repetitions.

Lesson 2: Space Each Statement, But Not Too Much

In Experiment 3, participants viewed statements in one session and judged their truth in a second session a week later. In this experiment, repetitions of the statements were separated between a range from no lag to 32 (i.e., high lag) items. As shown in the plot below, truth ratings increased as the number of lags between statements increased – to a point. After Lag 16, truth ratings decreased.

So, next time you see a Tweet or Facebook post, remember that perceived truth may be positively related to the number of times you've seen the microblog and the number of items you saw between (to a point).