You may have heard someone say something you heard from someone else before, and you assumed it to be true.
The Repetition Effect
It has a certain truthiness to it, as Stephen Colbert might put it. This is the essence of the “Repetition Effect”, which is when we hear the same thing over and over again. We tend to believe it’s true. These “facts” are an example.
The full moon causes people to act in unusual ways
Most people use only 10% of their brains
These statements are false. However, in today’s information-driven world, who has the time to verify everything? There are many social media channels that allow us to share a lot of information. This “sounds true” issue makes it difficult to know what is true.
A Class Demonstration Of The Repetition Effect
This demonstration was created by Professors Unkelbach and Koch, as well as Garcia-Marques. Essentially:
Present 8 statements to students (e.g. “The People’s Republic of China was established in 1947” and “It takes twice the force to move one ton of freight by rail than by truck.”
Ask students to rate each statement using a 1-to-7 scale. This scale will indicate how true the statement is.
Give yourself some time for the class to pass, or wait until the next class period.
Ask students to rate the truth of 20 statements. Eight of these statements were taken from the previous test. These 8 statements are false.
Have students calculate their truth estimates for these 8 statements.
Students will notice that 8 statements have risen in truth scores when they are asked to average their scores from the first and second readings. This is because they are familiar with them.
Unkelbach, Koch, and Garcia-Marques have provided a link to the PowerPoint deck that contains the statements in their article “Repeating Is Believing.” We bet it will spark a lively discussion about fake news with your students.
Resources:
Unkelbach, C., Koch, A., Silva, R., & Garcia-Marques, T. (2019). Truth by repetition: Explanations, implications. Current Directions in Psychological Science 28, 247-253. doi: 10.1177/0963721419827854
The Repetition-Induced Truth Effect: What is it like to Believe?
I’ve heard it before, so it must be true