The face you saw in the mirror this morning was not the face anyone else saw when they looked at you over breakfast. The two are related but not identical. Most human faces are slightly asymmetric — the eyes are at slightly different heights, the smile pulls more strongly on one side than the other, the hair parts on one side, freckles sit in specific positions that do not perfectly mirror across the vertical axis. When you look in a mirror, you see one version of your face, with left and right reversed relative to what other people see. When other people look at you, they see the opposite. You have, over the course of your life, become deeply familiar with one of these two versions. They have become familiar with the other. Neither version is wrong. Both are, however, surprisingly different from each other in ways that affect how each party perceives the same underlying face.
According to a 1977 paper by Theodore Mita, Marshall Dermer, and Jeffrey Knight published in the Journal of Personality and Social Psychology, the experimental setup that established this phenomenon was straightforward. The researchers took a frontal photograph of each of 37 women — undergraduate psychology students at the University of Wisconsin-Milwaukee — and printed each photograph twice: once as a true image (showing the face as a camera or another person would see it), and once as a mirror-flipped image (showing the face as the subject herself would see it in a bathroom mirror). The subjects were then shown the two versions side by side and asked which they preferred. The same pairs were shown to the subjects’ friends and lovers, who were asked the same question. The results, in both Study 1 and a subsequent Study 2, were striking and consistent. The subjects themselves preferred the mirror-flipped version of their own face. Their friends and lovers preferred the true version.
Why this happens
The mechanism underlying the effect is one of the better-established findings in social psychology: the mere-exposure effect, first proposed by the University of Michigan psychologist Robert Zajonc in 1968. As described in Gizmodo’s coverage of the mere-exposure mechanism behind the mirror preference, the mere-exposure effect is the phenomenon by which repeated exposure to a stimulus increases a person’s preference for that stimulus. The more often you encounter something, the more comfortable you become with it, and the more positively you evaluate it on subsequent encounters. The effect operates across an enormous range of contexts. People develop preferences for songs they have heard repeatedly, for faces they have seen frequently in public, for words that appear often in their reading, for foods they have eaten before. It does not require any explicit reasoning or evaluation; it works at the level of automatic familiarity processing.
The mirror-image preference is a particularly clean demonstration of the effect because the two stimuli being compared — the true image and the mirror image of the same person’s face — are objectively almost identical. The asymmetries are small. The lighting is the same. The expression is the same. The only difference is which side of the face is on which side of the photograph. The subject has, over the course of her life, spent many thousands of hours looking at one specific version. Her friends and lovers have spent many thousands of hours looking at the opposite version. When the two parties are then asked which version “looks more like” the person in question, or which version is more attractive, each party prefers the version they have been seeing all along. Neither is wrong. Each is simply applying the mere-exposure effect to the version of the face they have the most experience with.
What this implies about self-perception
Per the Mita et al. paper’s broader theoretical discussion, the finding has implications that extend well beyond the specific experimental setup. The general principle is that the version of yourself that you have internalised as canonical — the face you recognise as belonging to you, the face you adjust before going out, the face whose minor blemishes and asymmetries you have catalogued in detail — is a version that essentially nobody else has ever seen. Every photograph anyone else has ever taken of you. Every memory anyone else has formed of your face. Every impression you have made on a stranger across a room. All of these have been based on the opposite version of the face from the one you have been carrying around in your own head.
This is the underlying psychological mechanism behind the common experience of looking at a photograph of yourself and finding it subtly wrong. The face in the photograph is the true image — the version other people have been seeing all along — but it does not match the mirror image you have spent your life looking at. The mismatch produces the small but real sense of discomfort that most people experience when seeing themselves in photographs, particularly photographs they did not pose for and in which they had no opportunity to adjust their expression before the shutter clicked. The photographs are not unflattering. The photographs are accurate. Your face is mirroring back at you, several centimetres off from where you expected it to be.
The selfie problem
The modern environment has complicated the picture in ways that the Mita team could not have anticipated in 1977. As covered by Goody Feed’s analysis of how mirror-image preferences apply to selfie photography, most smartphone cameras now display selfies in the front-facing camera as a mirror image of the user — because that is what the user is accustomed to seeing — and then save the resulting photograph in one of two ways, depending on the phone model and the specific app being used. Some phones save the mirror-flipped version (the version the user saw in the viewfinder). Others save the true version (the version other people would see). The user is, accordingly, receiving inconsistent feedback about which version of their face is “really” them. A selfie that looked fine in the camera viewfinder may appear subtly wrong when reviewed afterwards, because the photo has been flipped to the true orientation. The same selfie viewed by a friend may look slightly strange to the user but entirely normal to the friend, who has been seeing that orientation of the face all along.
The broader implication, beyond the specific case of selfies, is that nearly every modern human is now navigating a world in which both versions of their own face are routinely available — the mirror version every morning in the bathroom, the true version in every photograph, video, and reflective non-mirror surface. The two versions are different enough that the brain registers the discrepancy. The version each person has learned to recognise as their own is, by all available evidence, the one that other people have not seen, except in the rare case of looking at the person directly while standing on the opposite side of a mirror. Everyone else has been seeing the other one. Your face, the one in your head, is essentially the reverse of the one the world has been looking at for as long as you have had it.
