The research behind the Mere Exposure Effect
A song you initially find unremarkable starts sounding better after you have heard it several times. A fashion trend that looked strange six months ago eventually looks completely normal. You repeatedly see the same person at a café or in a class and, without knowing much more about them, they begin to feel familiar.
We usually assume that liking something tells us something about the thing itself. Perhaps the song is good, the style suits us or the person seems appealing. But psychologists have found that our preferences can also be influenced by something much simpler: how often we have encountered something before.
This phenomenon is known as the Mere Exposure Effect. Psychologist Robert Zajonc helped establish it experimentally in the 1960s, showing that repeated exposure to an initially unfamiliar stimulus could increase people's positive evaluations of it even when the repetition provided no meaningful new information.
Familiarity, in other words, can affect preference on its own.
THE RESEARCH
In a widely cited 1968 paper, Zajonc brought together a series of experiments examining the relationship between repeated exposure and liking.
The stimuli were deliberately chosen so that participants would have little or no existing relationship with them. In different experiments, people encountered things such as unfamiliar symbols, nonsense words and photographs of faces. Some stimuli were presented repeatedly while others appeared much less frequently.
Participants were later asked to evaluate them.
Across the experiments, a consistent pattern emerged: stimuli that had been presented more frequently tended to receive more positive evaluations.
One experiment used unfamiliar Chinese-like characters for participants who did not know their meaning. The characters appeared at different frequencies. Participants were later told that the symbols represented adjectives and were asked to guess whether each one had a positive or negative meaning.
Characters they had seen more frequently were more likely to be judged positively.
Nothing about the meaning of the characters had changed. Participants had not been given additional evidence that the frequently presented symbols represented better concepts.
The primary difference was familiarity.
Zajonc argued that repeated exposure itself could therefore be sufficient under certain conditions to change our attitude towards something.
THE FINDING
The Mere Exposure Effect challenged the idea that preferences must always develop because we acquire new information about an object.
Sometimes we do learn more and then reasonably change our minds. You may like a person more after discovering that they are funny or generous. You may enjoy a food more after trying a better version of it. You may come to appreciate a piece of music because you begin to understand its structure.
Mere exposure is different because the repetition itself can influence evaluation.
Later research replicated the general effect across many kinds of stimuli, including images, sounds, words, shapes and people. Meta-analytic work has also supported the existence of a reliable relationship between repeated exposure and increased liking, while showing that the size of the effect depends on factors such as the type of stimulus, number of exposures and the way preference is measured.
The effect also tends to be particularly relevant when the stimulus is initially unfamiliar or relatively neutral.
This makes intuitive sense. If you already have an extremely strong opinion about something, simply seeing it again may not substantially change that opinion. Familiarity has more room to influence evaluation when your initial judgment is weak or uncertain.
THE THEORY
Why would familiarity make something feel better?
Researchers have proposed several explanations, and the mechanism is not reducible to a single process. One influential account involves processing fluency, or the ease with which the brain processes information.
When you encounter something for the first time, it requires more processing. The pattern is unfamiliar. You do not yet know what to expect from it.
After repeated exposure, processing becomes easier.
That ease can itself influence judgment. Information that is easier to process may feel more comfortable, less uncertain or more positive. Importantly, we do not necessarily recognize that familiarity is contributing to the feeling.
Another explanation involves uncertainty and safety. Novel stimuli can carry ambiguity simply because we do not know what they are. Repeated exposure without negative consequences provides information, even if only implicitly, that the stimulus is probably not threatening.
These explanations are not mutually exclusive. Familiarity can affect perception through several pathways and the exact mechanism may depend on what is being encountered and under what conditions.
The larger point is that our reaction to something can change even when the thing itself has not.
NOT THE SAME THING
Familiarity is not the same as quality
The Mere Exposure Effect does not mean that your preferences are arbitrary or that you only like things because you have seen them repeatedly.
There are countless reasons to prefer one person, place, object, idea or piece of music over another. Quality, personal values, associations, usefulness, aesthetics and previous experiences all contribute.
Repeated exposure is simply another influence.
There are also limits to the effect. Repetition does not guarantee increasing preference forever. At high levels of exposure, people can become bored or irritated. A song you initially grow to like can eventually become the song you cannot stand hearing again.
Initial reactions matter as well. If something is strongly unpleasant, threatening or irritating, repeated exposure does not necessarily transform it into something appealing. Under some conditions, repetition can reinforce the negative reaction.
The Mere Exposure Effect is therefore not a rule that familiarity always produces liking. It describes a tendency for repeated exposure, particularly to initially neutral or unfamiliar stimuli, to shift evaluations in a more positive direction.
WHY IT MATTERS
The effect becomes particularly interesting when we think about where preferences come from.
We tend to experience taste as something deeply personal. You like certain music, clothing, interiors, foods, neighborhoods and people because they feel like you.
And they may genuinely reflect you.
But your preferences also develop inside an environment.
You have been exposed to some kinds of music thousands of times and others almost never. Certain styles of clothing appear repeatedly in the places you live, the media you consume and the social groups around you. Some cuisines are familiar from childhood while others first appear in adulthood. Certain ways of living seem normal because you have repeatedly watched people live that way.
Familiarity does not completely determine preference, but it can help shape the field from which preferences develop.
This is particularly relevant in environments built around repeated exposure. Advertising has long relied on repetition. Social media adds another layer because algorithms can repeatedly place the same aesthetics, products, people and ideas in front of us.
Something can gradually move from unfamiliar, to recognizable, to normal, to appealing without a clear moment when we consciously decided that we liked it.
This doesn't mean the resulting preference is somehow fake. Preferences are influenced by experience. Familiarity is part of experience.
But it does complicate the assumption that everything that immediately feels right or attractive must reflect an independent preference that existed before we encountered it.
Sometimes taste is discovered.
Sometimes it is developed.
TRY THIS
Think of something you like now that you did not immediately like when you first encountered it. It could be a type of music, a food, a style of clothing, an artist, a neighborhood or an aesthetic.
Try to remember what your original reaction actually was.
Then consider what happened between that first encounter and your current preference. Did you learn something new that changed your evaluation? Did the thing itself improve? Did your circumstances change?
Or did you simply encounter it repeatedly until it stopped feeling unfamiliar?
You do not need to conclude that your current preference is somehow less genuine because familiarity helped create it. The more interesting point is that taste is not always fixed before experience begins.
It can develop through experience itself.
That is also worth remembering when something new doesn't immediately appeal to you. A first reaction provides information, but it isn't necessarily a final verdict. Sometimes what changes our relationship with something is not discovering a persuasive reason to like it.
Sometimes we simply get to know it.
References
Bornstein, R. F. (1989). Exposure and affect: Overview and meta-analysis of research, 1968-1987. Psychological Bulletin, 106(2), 265-289.
Montoya, R. M., Horton, R. S., Vevea, J. L., Citkowicz, M., & Lauber, E. A. (2017). A re-examination of the mere exposure effect: The influence of repeated exposure on recognition, familiarity, and liking. Psychological Bulletin, 143(5), 459-498.
Zajonc, R. B. (1968). Attitudinal effects of mere exposure. Journal of Personality and Social Psychology, 9(2, Pt. 2), 1-27.