Cognitive biases
The mere-exposure effect: why we like the familiar more
Every morning on her way to work, Nika rides the bus past a small coffee shop with a green sign. She has never been inside. On Saturday a friend invites her for coffee and suggests two places nearby: this shop and another one on the next street, which Nika knows nothing about. The prices are similar, and so are the reviews. “Let’s go to the one with the green sign,” Nika says. “It just feels nice.” Why it feels nice, she can’t explain.
This is the mere-exposure effect: when we meet something unfamiliar again and again, we usually come to like it more simply because it has become familiar. We have not learned anything good about it. The meetings alone are enough. With very frequent repetition, the effect weakens.
Below, we look at what research has shown, why the familiar feels more pleasant, and when this gets in the way of choosing. In the middle of the article you will ride down the street with Nika and pick the icons you like better.
Contents
In short: how the mere-exposure effect works
What the mere-exposure effect is
“Mere exposure” is what psychologists call it when a person is simply shown something. No explanations, no praise, no reward. The main idea of the effect: sometimes that alone is enough for people to start feeling warmer toward the thing.
The idea was described by the psychologist Robert Zajonc in a 1968 paper. He showed people meaningless words and unfamiliar symbols: some many times, others less often. Then people guessed whether each word and symbol had a good or a bad meaning. The ones shown more often were more likely to be judged good.
What came next was even more surprising. In another experiment, shapes were shown so briefly that people could not recognize them afterward. Still, they liked the shapes that had flashed before better. It later turned out that with such flashes the effect can be even stronger than when the picture is clearly visible. This does not mean that a hidden “25th frame” works in advertising: in these experiments people only said which picture they liked more, and they bought nothing.
How far the effect can be trusted. In a large review of studies from 2017, scientists pooled the results of many papers. For pictures and symbols, the pattern is this: liking grows with the first repetitions and starts to drop when they become very frequent. For sounds, such as melodies, no such pattern was found, so songs may work differently. The authors also write that none of the earlier explanations accounts for all the results. The effect itself holds up, but scientists still argue about why it works this way.
Try it yourself: Nika’s street
The game takes about a minute. Here is what will happen.
Step 1. You ride to work with Nika and look out the window. Signs of unfamiliar cafés flash by. They have no names, only made-up icons. Just watch: there is nothing to press or memorize.
Step 2. In the evening Nika chooses where to go in. She shows you the icons in pairs: six pairs, one at a time. In each pair, tap the icon you like better.
Step 3. At the end we show what came out and reveal the trick.
Why are the icons made up? So that none of them is familiar to you in advance. Which icons appear on the street and in what order is chosen by the computer, and it is different for every player.
What usually happens. In each pair, one icon flashed by on the street 5 times and the other only once. If frequency had no effect, you would pick the familiar icon in about half the pairs: around 3 out of 6. In studies, people on average more often pick what they have seen more often.
What the game can and can’t show. Six pairs are too few to judge one person: a couple of random picks easily shift the result. So your result is a hint, not proof. Besides, you read the start of the article and knew what it was about. In one study, people liked the familiar less when they were given a clue about where the feeling of “familiar” comes from. The same could have happened to you.
When it is not a mistake. If Nika has been to the coffee shop ten times and liked it there, her choice rests on experience. That is not the mere-exposure effect. The familiar is also often more reliable: it has already been tested. It becomes a mistake when we like something we don’t actually know only because it kept catching our eye.
Why the familiar feels more pleasant
The familiar is easier to take in. What we have already seen, the brain recognizes faster and with less effort. Psychologists call this ease fluency. We don’t notice it, but it is pleasant, and we credit that pleasant feeling to the thing itself: “It just seems nice.” Scientists tested this with no repetition at all. They made a picture a little sharper or showed it a little longer, so that it was easier to make out. And people liked it more.
Think of broken-in shoes. They are not prettier than new ones, they are just already comfortable. This is an image, not a precise description of how the brain works. But it conveys the main point: ease is easily mistaken for “I like it.”
We don’t remember where the feeling comes from. Nika did not count how many times she passed the green sign. She did not even pay attention to it. All that was left was the feeling “it’s nice.” This is an everyday observation, but it explains why the effect is so hard to catch in ourselves: the choice just feels like taste.
Where it gets in the way
Shopping. In a store, your hand reaches for a brand you have seen in ads many times, though you have never tried it. The unfamiliar one next to it may be no worse. Advertising often just flashes by again and again, proving nothing. This is an everyday observation.
New things. A new song, a new dish, a new person on the team often feel “off” at the first meeting. Partly just because they are not familiar yet. If we judge by one meeting, it is easy to turn down something we would like later. This is an everyday observation, but it follows directly from the effect.
Your own face in photos. Sometimes we don’t like our own photographs. In one experiment, people were shown two pictures of their face: a regular one and a mirror image. They themselves more often chose the mirror image: that is how they see themselves in the mirror every day. Their friends and loved ones more often chose the regular one: that is how they see this face.
Repetition affects not only what we like but also what seems true. That is covered in the article on the illusory truth effect. And the liking for the usual option we already have is described by status quo bias.
How to tell “I like it” from “I know it”
The mere-exposure effect is one of the biases on the cognitive bias map, in the section on what we notice. Right there is the bandwagon effect: why the popular seems better.
Frequently asked questions
How is this different from the illusory truth effect?
Both effects are about repetition. But the mere-exposure effect is about what we like. The illusory truth effect is about what we believe: a familiar phrase seems truer than a new one.
So the more often, the more we like it?
Not without limit. For pictures and symbols, liking first grows, and with very frequent repetition it starts to drop. That is why advertising shown too often can also become annoying.
Is choosing the familiar always a mistake?
No. If you know the thing from your own experience and it was good, that is a reasonable basis for choosing. The familiar is often more reliable because it has already been tested. The mistake begins when we like something we know nothing about only because it kept turning up.
