How Liars Create the Illusion of Truth

Posted on January 3, 2017

The illusion of truth occurs when something is repeated so often that an individual believes it to be true. How does this happen? Experiments testing the effect discovered that participants are more likely to rate a statement as true if they have previously been exposed to it. That is, believing something to be true seems to involve how familiar you are with the statement. The more you hear or see it, the more likely you are to think it's real.

So if everyone tells you that the grass is purple, regardless of what your eyes tell you, does that mean you would start to believe in purple grass? Well, not necessarily! One thing we have to combat against this illusion of truth is our prior knowledge. If you already know that something is false, repetition won't affect your belief. What it will affect is how plausible something seems. Lisa Fazio and her colleagues from Vanderbilt University discovered that repetition can still affect our judgements in situations where we are unsure. That is, if you don't know something then repeating it will sway you to believe that it is true. Overall, repetition can make things seem more believable, even if we know otherwise, but it doesn't over-ride our existing knowledge.

So why do people fall prey to the illusion of truth? Tom Stafford explains that it is because our minds have to make fast judgements without using too much of our resources. To do so we use shortcuts when making decisions. One strategy the brain has to determine if something is true is depends on how often you hear it. Sometimes it works, but sometimes it can be misleading.

Repeating things can cause the line between fact and fiction thin and hard to distinguish. To protect yourself from the illusion of truth, do a little research and find the origin or reference instead of relying on rumor. Think before you repeat!


Source material from Mind Hacks