In April 15, 2013 Dove launched a 3-minute video entitled “Dove Real Beauty Sketches.” The video achieved instant popularity and has been watched millions of times — a successful viral campaign which has been widely talked about. In the video, a small group of women are asked to describe their faces to a person whom they cannot see. The person is a forensic artist who is there to draw pictures of the women based on their verbal descriptions. A curtain separates the artist and the women, and they never see each other. Before all this, each woman is asked to socialize with a stranger, who later separately describes the woman to the forensic artist. In the end, the women are shown the two drawings, one based on their own description, the other based on the stranger’s description. Much to their amazement and delight, the women realize that the drawings based on strangers’ descriptions depict much more beautiful women. The video ends: “You are more beautiful than you think.”

The idea is quite appealing. Perhaps too many women are unhappy with their looks. It would be a big relief if we all suddenly realized, like Christian Andersen’s ugly duckling, that we are in fact beautiful.

However, what Dove is suggesting is not actually true. The evidence from psychological research suggests instead that we tend to think of our appearance in ways that are more flattering than are warranted. This seems to be part of a broader human tendency to see ourselves through rose colored glasses. Most of us think that we are better than we actually are — not just physically, but in every way.

The most direct evidence that the Dove commercial is misleading comes from the work of Nicholas Epley of the University of Chicago and Erin Whitchurch of the University of Virginia. In a series of studies, Epley and Whitchurch showed that we see ourselves as better looking than we actually are. The researchers took pictures of study participants and, using a computerized procedure, produced more attractive and less attractive versions of those pictures. Participants were told that they would be presented with a series of images including their original picture and images modified from that picture. They were then asked to identify the unmodified picture. They tended to select an attractively enhanced one.

Epley and Whitchurch showed that people display this bias for themselves but not for strangers. The same morphing procedure was applied to a picture of a stranger, whom the study participant met three weeks earlier during an unrelated study. Participants tended to select the unmodified picture of the stranger.

People tend to say that an attractively enhanced picture is their own, but Epley and Whitchurch wanted to be sure that people truly believe what they say. People recognize objects more quickly when those objects match their mental representations. Therefore, if people truly believe that an attractively enhanced picture is their own, they should recognize that picture more quickly, which is exactly what the researchers found.

Inflated perceptions of one’s physical appearance is a manifestation of a general phenomenon psychologists call “self-enhancement.” Researchers have shown that people overestimate the likelihood that they would engage in a desirable behavior, but are remarkably accurate when predicting the behavior of a stranger. For example, people overestimate the amount of money they would donate to charity while accurately predicting others’ donations. Similarly, people overestimate their likelihood to vote in an upcoming presidential election, while accurately predicting others’ likelihood to vote.

Most people believe that they are above average, a statistical impossibility. The above average effects, as they are called, are common. For example, 93 percent of drivers rate themselves as better than the median driver. Of college professors, 94 percent say that they do above-average work. People are unrealistically optimistic about their own health risks compared with those of other people. For example, people think that they are less susceptible to the flu than others. Stock pickers think the stocks they buy are more likely to end up winners than those of the average investor. If you think that self-enhancement biases exist in other people and they do not apply to you, you are not alone. Most people state that they are more likely than others to provide accurate self-assessments.

Why do we have positively enhanced self-views? The adaptive nature of self-enhancement might be the answer. Conveying the information that one has desirable characteristics is beneficial in a social environment. People may try to deceive others about their characteristics, but deception has two main disadvantages. First, it is cognitively taxing because the deceiver has to hold two conflicting representations of reality in mind: the true state of affairs and the deception. The resulting cognitive load reduces performance in other cognitive functions. Second, people are good at detecting deception and they show strong negative emotional reactions toward deceivers. Since in self-enhancement people truly believe that they have desirable characteristics, they can promote themselves without having to lie. Self-enhancement also boosts confidence. Researchers have shown that confidence plays a role in determining whom people choose as leaders and romantic partners. Confident people are believed more and their advice is more likely to be followed.

Dove’s premise is wrong. But thinking we are more beautiful than we really are may not be such a bad thing.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.