It can't be a lie, right?

Last summer, my friend and I have been walking through London, searching for a beauty salon. Soon we encountered something resembling a beauty store with some makeup counters. We were pleased because in this kind of stores, the makeup application is usually a part of product demonstration and hence it is free or inexpensive. Little did we know that we would be walking out of this very store with £200 worth of skincare products, proving the store's persuasive techniques to be effective.

We walked in, and in a brief moment, a man approached us introducing himself as a manager of the store that has decided to take us under his expert wing. We explained we were only looking to get some quick makeup done, but he would soon charmingly move the conversation into telling us about this 'miracle cream' that is supposedly the store's bestseller and the stars' favorite; while he would rub scented products on our hands and telling us about how amazing our skin would look in just three weeks. But moreover, throughout the whole hour and a half long demonstration, he would keep bringing up the same statement: 'Our miracle cream is the best on the market', and he'd accompany this speech with giving demonstrations and showing us glowing reviews.

In his article 'Making a Message Memorable and Persuasive', James Maclachlan introduces twelve persuasive techniques shown to be effective in wide varieties of contexts. One of these techniques is the technique of repeating key points. By increasing the number of times material is presented, it is better remembered. Moreover, the repeated ideas are judged to be more true, even when they are false (MacLachlan, p.54).

Goldstein, Hasher and Toppino have conducted a study in which their forty subjects have rated their certainty about the truth or falsity of 60 statements. The subjects were students and the statements were sampled from areas such as politics, government and medicine; plausibly but unlikely known by the students. Some of those statements were either repeated or not repeated on the list. The subjects were to rate each statement's validity on a 7-point scale, with four indicating 'uncertain', five indicating 'possibly true', six indicating 'probably true' and seven 'definitely true'. Twenty of the first sixty statements were selected as critical items and occurred on each of the three presentations. All other items were new. Validity ratings of the 20 repeated assertions were compared with those for nonrepeated statements. Crossed with the repeated and nonrepeated variable and the sessions variable, was a third variable, the actual truth or falsity of the assertion.

This research has demonstrated that the repetition of a plausible statement increases a person's belief in its truth.

The table above shows how the average rating assigned to repeated statements increased across successive sessions, while the rating assigned to nonrepeated statements diminished slightly.
Moreover, validity ratings assigned to repeated items increased across successive tests, while the validity ratings assigned to nonrepeated statements did not change.


MacLachlan, J. 1983. 'Making a Message Memorable and Persuasive'. Journal of Advertising Research. Dec83/Jan84, Vol. 23 Issue 6, p51. 9p.

Goldstein, D., Hasher, L., Toppino, T. 1977. 'Frequency and the Conference of Referential Validity'. Journal of verbal learning and verbal behavior,16, 107-112.