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Cognitive Biases

Illusion of Truth Effect

The illusion of truth effect is a cognitive bias where repeated statements are more likely to be believed as true, regardless of evidence. It explains why advertisements and propaganda rely on repetition to influence judgment.

THE IDEA

Illusion of Truth Effect

The illusion of truth effect is a cognitive bias where we tend to believe information is true simply because we have been exposed to it multiple times, even in the absence of supporting evidence. This effect is closely related to cognitive fluency: repeated messages become familiar and easier to process, leading us to accept them as valid. Advertisements, political slogans, and media can exploit this effect to influence public opinion. Before accepting a familiar claim, check what evidence supports it and consider contrary evidence.

When to use it

  • In marketing: creating brand recognition and trust through repetitive messaging.

  • In politics: spreading campaign messages and influencing voter perceptions.

  • In education: using repetition to reinforce learning, but ensuring facts are accurate.

  • In everyday life: recognizing manipulation when a claim is repeated excessively.

FROM THEORY TO EVERYDAY LIFE

In practice

01

Advertising Repetition

A company runs the same commercial multiple times a day. Over time, viewers start believing the product claims, even if they have no factual basis, simply because they've heard them so often.

02

Political Slogans

A political candidate repeats the same catchphrase in every speech and ad. Voters may come to accept the slogan as truth without questioning its accuracy.

✳

A MOMENT TO REFLECT

Put it to work.

  1. How often do you accept a statement as true simply because you've heard it before?

  2. In what areas of your life might the illusion of truth effect be influencing your beliefs?

  3. How can you verify the truth of commonly repeated statements?

Connected ideas

Another lens can bring the same problem into focus.

CONTINUE THE CONVERSATION

Source texts

  • The 25 Cognitive Biases Uncovering The Myth Of Rational Thinking (Charles Holm)
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