The illusory Truth Effect: Why Repetition Makes False Information Seem True

Commercial product advertisements are repeated so often that false messages are perceived as true. In its ads, Coca-Cola portrays healthy, cheerful young people, masking the depressing consequences of diabetes and obesity. Online loans are portrayed as a quick, safe, and convenient solution to financial problems, masking dangerous financial risks that can lead to anxiety and restlessness.

Everyday life is filled with illusory truths. They appear to be true but are actually false. We tend to perceive them as true because repeated exposure increases their familiarity, making them seem more credible. In psychology, this phenomenon is called the illusory truth effect, where repeated information is often perceived as more accurate than new information.

Research on the illusion of truth effect was first conducted by Lynn Hasher, David Goldstein, and Thomas Toppino, reported in their research article, Frequency and the Conference of Referential Validity. In their experiment, participants were presented with a list of 60 plausible statements in 10 fields, including history, geography, and art. Some of these were true, and some were false. For example, two statements in the field of art read as follows:

“Ernest Hemingway received the Pulitzer Prize for his novel The Old Man and the Sea ” (True)

“The largest museum in the world is the Louvre in Paris” (Wrong).

Participants were asked to rate the truth of each statement three consecutive times over a two-week period. However, during the second and third sessions, half of the statements were previously encountered, while the other half were unseen. The results showed that in each subsequent session, participants rated the repeated statements as truer than they had in the previous session. The researchers concluded that the frequency of occurrence of statements was the criterion used by participants in assessing the truth of a statement.

The illusion of truth is a common occurrence in everyday life, including in advertising. One example of the illusion of truth in advertising is presented by historian Yoval Noah Harari in his book, “21 Lessons for the 21st Century .” In the 17th lesson on post-truth , Harari explains that commercial companies rely on the power of fictional stories to brand their products, repeating them repeatedly to be perceived as true. Harari writes,

Branding often involves retelling the same fictional story over and over again, until people believe it’s true. What image comes to mind when you think of Coca-Cola? Do you picture healthy young people exercising and having fun together? Or do you picture an overweight diabetic lying in a hospital bed? Drinking lots of Coca-Cola won’t make you young, it won’t make you healthy, and it won’t make you athletic—in fact, it will increase your risk of obesity and diabetes. Yet for decades, Coca-Cola has invested billions of dollars in associating itself with youth, health, and sports—and billions of people subconsciously believe this association.

If we examine it, there are many illusions of truth that arise from commercial companies attempting to shape and change public attitudes toward their products. This is done solely to profit from positive public attitudes toward the product, ultimately leading to consumer purchase, even though the product actually offers no benefits and may even have negative impacts on consumers.

Here are some of the effects of the illusion of truth:

1. Cigarette advertisements portray men as masculine, successful, loyal, adventurous, full of stamina, energetic, and creative. Yet, cigarette packs clearly warn that smoking can lead to a number of health problems, including mouth and throat cancer, heart attacks, and more.
2. An advertisement for processed nugget food carries the tagline, “So Good is very good .” Are nuggets really that good? Nuggets are a processed product high in fat, preservatives, and low in nutritional content.
3. Beauty products advertise promises of whitening skin instantly. Some brands even advertised black faces instantly turning white after using the product, but the ads were eventually withdrawn after protests for their racist content. However, using whitening products can have side effects, including skin damage and even cancer.
4. The children’s favorite food, Kinderjoy, features an advertisement depicting the joy of a young family returning home, where the mother presents this product as a gift as a token of appreciation for her children’s kindness. How much sugar does this tiny food contain? Of the 20 grams of this product, half (10 grams) is sugar. However, for children, consuming too much sugar-containing food can lead to tooth decay, decreased memory and concentration, obesity, and diabetes.
5. In various versions of its advertisements, Indomie instant noodles display joy, warmth, togetherness, and family. The product is displayed with appetizing illustrations with the tagline “Indomie is my taste.” The advertisements that are repeated continuously build the view in the minds of consumers that when you don’t have an appetite, eat Indomie. When there is no food in the kitchen, cook Indomie. How could it not be delicious, instant noodles contain high levels of MSG and salt that make them delicious and savory on the tongue. Instant noodles are high in carbohydrates and fat but low in protein, vitamins, and minerals . The truth is that consuming too many instant noodles has a number of risks including malnutrition, digestive disorders, kidney problems, and cancer.
6. Energy drinks are advertised as a quick way to boost energy, lift spirits, enhance performance, and achieve dreams. These ads encourage consumers to consume them more frequently, even daily. However, excessive consumption of energy drinks can have adverse health effects, including sleep disturbances, anxiety, kidney and heart problems.
7. Advertisements for (legal) online loans promise to help consumers solve their financial problems quickly. Tunaiku, as I read on the back of a commuter train carriage, has the tagline “safe and comfortable.” AdaKami offers loans that “won’t make your head feel like it’s being struck by lightning.” The truth is, borrowing, even if legal, carries a number of financial risks, such as interest charges and fines upon maturity (the fines can reach 100 percent of the loan!). Another risk is the presence of unexpected visitors ( debt collectors) if you fail to pay. Not to mention, consumers will be charged from all directions. It’s truly unsafe, uncomfortable, and more than a lightning strike! Wait, aren’t consumers helped borrowing online for productive purposes, as business capital? On its website, AdaKami’s product meets “various needs, both productive and consumptive, with a fast and easy application process.” However, most of its advertisements persuade people to act in a consumptive manner. For them, borrowing for productive or consumptive purposes doesn’t matter as long as more consumers borrow money. They pretend to care about our financial problems, but in reality, they don’t.
8. And many more.

Why is false information, when repeatedly exposed, more likely to be judged as true? One of the most popular explanations is the so-called processing fluency account . In their article, The effects of repetition frequency on the illusory truth effect, Aumyo Hassan and Sarah J. Barber explain the following:

Processing fluency refers to the metacognitive experience of ease or difficulty accompanying a mental process. According to the processing fluency explanation, when information is repeated, it is processed more fluently and, consequently, perceived as more believable. This judgment occurs because we have learned over time that fluency can predict truthfulness. Support for the processing fluency explanation comes from other research showing that the illusion of truthfulness can occur even without repetition, such that people judge information presented in an easy-to-read font or easy-to-understand speech as more believable than information presented in a less perceptually fluent format.

How can we avoid the effects of the illusion of truth? Here are two ways.

1. The illusion of truth effect exploits human weaknesses in thinking, which tend to be cognitively miserly through quick, heuristic thinking. Therefore, if we receive information repeatedly, start using slow thinking by questioning and investigating its truth.
2. Because the illusion of truth can lead many people to believe something is true when it’s actually false, we need to suppress our tendency to conform to social pressure. We need to be non-conformist to the views and behaviors built on this illusion of truth. For example, amidst the onslaught of cigarette advertisements portraying smoking as a positive behavior, we can still be proud to be non-smokers and maintain an energetic, creative, and warm personality, even though many people around us smoke.

Cognitive miser is one of the four reasons why people are easily deceived. Personality-wise, humans also have a tendency to be easily persuaded, a trait known as gullibility. People with high gullibility tend to be easily persuaded and insensitive to signs of deception.

This article is an English (Google-translated) version of Efek Ilusi Kebenaran: Mengapa Pengulangan Membuat Informasi Salah Dinilai Benar?