The Illusory Truth Effect is a principal of psychology regarding the fact that when something is repeated often enough, people will believe it’s true even if it is untrue. The Illusory Truth Effect was first identified in 1977 by scientists from Villanova University and Temple University. Since then it has been replicated in many more studies.

We know repetition is used everywhere – advertising, politics and the media. We see ads for the same products over and over again. We see  this technique is a staple of propaganda where politicians and CEO’s are provided  soundbites and slogans to repeat at every opportunity. Politicians repeat the same message they want voters to believe endlessly (even when it has nothing to do with the question they’ve been asked). The result is listeners acceptance of the claims made and that happens even when the claims have clearly been proven untrue.

Some studies have tested how many times the message should be repeated for maximum effect. These studies indicate that generally the message should be repeated 3 to 5 times for maximum impact.

Recent studies have shown that the Illusory Effect is much stronger than previously thought. In a study published in the Journal of Experimental Psychology it was found that the Illusory Truth Effect is effective even with people who really should know better. It turns out that even if a person has prior knowledge disproving the lie being repeated, they will still believe it if repeated often enough.

How do you deal with this psychological fact? One of the things psychologists have learned is that just responding by citing facts to refute a claim often backfires. Doing so causes more attention to the false claim and causes people to become defensive over their existing beliefs making them even more convinced the false claim is true. In addition, it’s been shown that correcting lies by a negative denial while repeating the lie is ineffective. For instance, one study found that a statement: “John is not a criminal” enhances the opposite conclusion because the subconscious mind always ignores the negative part of a statement. That’s why our responses and even our self statements to motivate should be in the positive: “I will speak slowly and loudly” rather than the negative: “I will not talk too fast or too quietly so everyone can hear me.”

UC Berkeley cognitive linguist George Lakoff is the recognized authority on this general subject. He suggests that one should always talk about the truth first, briefly note the lie and conclude with the truth. He sometimes calls this idea a “truth sandwich.” He notes that studies indicate we remember beginnings and endings far better than what is said in the middle, hence his recommended framing.  For example: “The fact is John is a good citizen but some have falsely claimed otherwise. Let’s focus on his many civic accomplishments to know the real truth.” Simply repeating the lie and saying it’s not true has the opposite result then intended. Stating truth as a positive fact with the correct framing is the right approach.

Given the power of repetition trial lawyers should be taking advantage of this psychological phenomenon by the repetition of their case themes, significant issues and compelling facts. At the same time, it behooves us to bear in mind the defendants repetition of misleading or false claims contains the risk of juror acceptance. In both cases, we need to begin practicing the concept in jury selection as well as through opening statement and the entire trial.