Who am I? The question seems so simple, yet it cuts to the heart of everything we do. Without an answer, we lack the inner compass that guides us through life. Decisions become arbitrary. Relationships dangle by a tenuous thread.

Introspection offers partial insight into this nebulous yet vital question. A fuller account, however, emerges from our interactions with the social environment. As we move through the world, certain people, ideas and activities resonate more than others. This mix of allegiances is ultimately what makes you you.

A defining force in the shaping of identity is a person's drive to be different and special. Psychologists define this facet of personality as the need for uniqueness. Their research has revealed that every one of us seeks uniqueness to some degree. Those who have little need for uniqueness tend to find comfort in familiarity. Others strive to be extreme outliers. Most of us fall somewhere in between.

Even for the most exotic among us, the need for uniqueness is counterbalanced by a desire to fit in. Consider, for example, the hypothetical case of a Fortune 500 businesswoman with a thoroughly pierced face and a Mohawk. Most likely she feels very much at home around others with a similar look. In a corporate boardroom, however, she probably feels ill at ease. The reason is context: in the first case, she surrounds herself with like-minded people, a group to which she feels she belongs. Because these two social circles—those who embrace a punk aesthetic and those who sit in boardrooms—rarely overlap, we almost never encounter such edgy executives. Herein lie the yin and yang of uniqueness: somewhat paradoxically, we set ourselves apart by affiliating with groups of people more like us. Uniqueness emerges from the distinct combination of alliances that only you seek out.

The natural drive to be unique has broad effects. It informs purchasing decisions. It affects appearance, for example, through hairstyles and tattoos. And it is an important driver of innovation. Many major discoveries emerged from the minds of scientific outsiders. Think of Albert Einstein, the patent office clerk who chafed under the strictures of academia but thrived once he could pursue his interests in autonomy. Or consider Marie Curie, the first woman to achieve numerous accomplishments in science, culminating in two Nobel Prizes. Had she conformed to the social expectations for her gender, the world would have been deprived of her many contributions. In short, uniqueness enhances creativity. So let your true self shine through—the world might thank you for it.

Fitting in vs. Sticking Out
The idea of a need for uniqueness has a long history in psychology, originating with the study of its counterpart, conformity. Psychologist Solomon Asch attained renown in the 1950s for demonstrating that a person's views are vulnerable to the opinions of the majority. In his now classic experiment, a participant sat in a room with several other people, all of whom had been secretly hired by Asch and his colleagues. The task was to look at a line and then pick which one of three other lines most closely resembled the initial prompt. Given the way the task was designed, identifying the proper line ought to have been exceedingly simple.

But the experimenters set up the situation so that the actors they had hired all responded before the real participant, and they all gave the same wrong answer. When the participants' turn came around, about a third responded just as the actors did—an astounding fraction, given that the correct choice was crystal clear. Later, when they were asked why they gave the wrong answer, the subjects recalled the uncertainty they had felt at the time. Although they had initially arrived at the proper response, they began to doubt themselves and concluded that the group was probably right.

Variations on Asch's initial study revealed that factors such as the size of the group, the presence of a dissenter or two, and the group's overall status could alter how many participants ultimately go against the grain. Nevertheless, as Asch concluded, “that we have found the tendency to conformity in our society so strong that reasonably intelligent and well-meaning young people are willing to call white black is a matter of concern. It raises questions about our ways of education and the values that guide our conduct.”

The matter of why and when people strike out on their own captured the interest of two other psychologists, Howard L. Fromkin, then at York University in Ontario, and his colleague Charles R. Snyder, then at the University of Kansas. In the 1970s they developed a theory that everyone craves uniqueness to some extent. They discovered that relatively simple questions can gauge the intensity of this need in a person, and so they devised a uniqueness scale. In it, respondents rate how strongly certain statements apply to them, such as “I tend to express my opinions openly, regardless of what others say,” “I like to go my own way,” and “I always try to live according to the rules and standards of society.”

Using Fromkin and Snyder's scale, one of us (Erb) and his colleagues looked at how the need for uniqueness mapped to the “big five” personality traits, the basic human characteristics recognized by most psychologists. (The five traits are extroversion, openness to experience, neuroticism, agreeableness and conscientiousness.) In a survey of approximately 150 students, we found that three of these traits are closely connected with the need for uniqueness. Individuals with a strong need for uniqueness tend on average to be extroverted. They are sociable and optimistic about life. They also tend to be open to new experiences. In addition, a pronounced need for uniqueness is associated with low neuroticism; such people generally are more satisfied with their life and have fewer mood fluctuations.

Despite their convivial nature, people who are high in their need for uniqueness also tend to care less about others' opinions, and they typically engage in creative activities more frequently than their mainstream counterparts. [For more on creativity, personal challenges and the need for uniqueness, see “From Contretemps to Creativity,” by Scott Barry Kaufman, on the next page.] The other two dimensions of the big five, agreeableness and conscientiousness, do not appear to be linked with either a strong or weak need for uniqueness.

Manipulating Uniqueness
Although a person's propensity to seek uniqueness is generally stable throughout life, certain situations can shift it temporarily. In a 2009 study conducted by psychologist Roland Imhoff, now at the University of Cologne in Germany, in collaboration with Erb, we wanted to investigate how making someon feel average might affect his or her subsequent behavior. To do so, we asked our subjects to fill out a personality test. We then gave them bogus feedback—half the participants were told they had very pronounced individual traits, at the same time the other half learned that their personality was simply normal.

Next we asked them how they felt about a debate regarding dining cars on trains. To test whether the personality test results altered their desire to stand out in the crowd, we showed them a chart that claimed that either 79 or 21 percent of respondents believed that dining cars should be dropped from German Federal Railway trains.

As we discovered, the subjects who had been told they were average were much more likely to opt for the minority opinion. In contrast, those who had been told they had notably unique traits tended to agree with the majority. We interpreted this as meaning that the people who had been led to believe they were unremarkable had felt that their individuality was threatened and thus offered a dissenting opinion as a way to differentiate themselves. People will express their individuality even in something as mundane as a debate on German dining cars.

The realization that the desire to both fit in and stick out can drive decision making has not been lost on retailers and product designers. People who wish to be seen as tough, for example, are more likely to sport a leather jacket. To come across as shrewd in business, a person might acquire a custom-tailored suit. These behaviors may seem commonsense, but the underlying motivation is to signal an individual's inner self to the outer world.

To understand how this need motivates consumer behavior, consider a study published in 2012 by graduate student Cindy Chan of the Wharton School of the University of Pennsylvania and her colleagues. They examined how purchasing decisions reflect a person's attempts to juggle identifying with a social group and maintaining individuality.

Chan and her co-workers suspected that consumers satisfy their competing motives on different dimensions of a given product. To test this idea, the researchers recruited college students who belonged to one of their university's eating clubs. Similar to fraternities, the eating clubs differ in their social identities, with one club attracting athletes, another drawing science and engineering students, and so on. The researchers took pictures of participants from three clubs and blurred the images so only the clothing remained visible. The students also filled out a questionnaire to measure their need for uniqueness.

Then a group of students drawn from those same three clubs viewed the photographs and guessed the subject's club. They also rated the uniqueness of that person's look as compared with others in his or her club.

As it turned out, the observers were good at their jobs. They were highly accurate when identifying a subject's club from his or her clothing in the photographs. They likewise guessed correctly which students had higher or lower needs for uniqueness. The finding suggests two things: that our taste in clothing broadcasts our identity to the people around us and that we can signal group membership and uniqueness simultaneously through choices of clothing.

But these results do not yet tell us how a person's choices can accomplish these two goals. Thus, in a set of follow-up experiments, Chan and her collaborators manipulated whether a participant felt like he or she was an insider or an outsider. They did so by asking their subjects to write about a group that they either did or did not feel a part of, such as an athletic team, a fraternity or a student council. As before, they also measured their participants' need for uniqueness.

Then they examined the participants' purchasing preferences. Similar to the setup of the German dining car experiment, these researchers showed subjects a set of products, revealed the preference of the group they had described, and asked them what they would choose. But the decision scenarios were multidimensional. For example, participants might choose not only between a BMW and a Mercedes but also between colors or models of the respective brands.

Those who had been made to feel like outsiders did not reveal any preferences. After all, they were not motivated to try to either join or reject the social group they had been thinking about. The participants who felt like insiders, however, were significantly more likely to select the brand that their group had opted for. They successfully communicated their membership in that social circle.

But the insiders who ranked higher in the need for uniqueness did not follow the majority all the way. The desire to separate oneself from the herd exerted its influence not in the brand but at the level of the product, through the choice of a model or color. People do not simply assimilate or differentiate—they can do both simultaneously along different dimensions of a decision.

A Matter of Culture
Not only do individuals differ from one another in their need for uniqueness, entire cultures do as well. The most striking, well-supported divide between the cultures of the world is that of individualism versus collectivism. Individualist cultures emphasize personal freedom and reward achievements that make a person stand out. The U.S., the U.K. and the Netherlands are prime examples.

Collectivism emphasizes community cohesiveness. These cultures—think Pakistan, Nigeria and Peru, as well as many countries in Asia—encourage members to strive toward shared goals. In a collectivist society, uniqueness has negative connotations, akin to deviance, whereas conformity is linked with harmony. It is a small step to translate these differing cultural priorities into divergent needs for uniqueness. In a study that compared the need for uniqueness of Malaysians and Americans, for example, researchers found considerably lower scores among the former.

In one 1999 experiment that explored the effects of cultural attitudes toward uniqueness, psychologists Heejung Kim, now at the University of California, Santa Barbara, and Hazel Rose Markus of Stanford University, recruited Americans and East Asians from the waiting areas at San Francisco International Airport. To disguise the true purpose of the study, the participants were asked fill out a short survey in exchange for a free pen. On completion, the experimenter reached into a bag and pulled out five green or orange pens such that one or two of the pens were always a different color from the rest. Which color a person selected was the real test. As it turned out, Americans opted for the more rare choice. They chose a pen of the minority color three times out of four, whereas only one in four East Asians chose the less common color.

Given the pronounced effect they saw, Kim and Markus wondered whether advertisers emphasize cultural themes in their efforts to entice buyers. In a survey of almost 300 advertisements, they found that Korean ads were twice as likely to highlight conformity than uniqueness, and American advertisers more commonly underscored how a product makes someone stand out.

If a need for uniqueness is linked with creativity, then a culture's orientation toward individualism could enhance that society's overall innovativeness. At the same time, the every-man-for-himself mentality that accompanies individualism could undercut a culture's ability to capitalize on its inventive thinking. Aligning a team's members toward a common goal—an easy task in a collectivist group—might be significantly harder to achieve.

To investigate this question, economists Yuriy Gorodnichenko and Gérard Roland of U.C. Berkeley compared data across countries and found strong positive correlations between a country's individualism and its measures of innovation. They also noted in their study, published in 2010, that increasing individualism enhanced a country's standard of living considerably. Thus, an increase in individualism of one standard deviation—say, from Venezuela to Greece or Brazil to Luxembourg—was linked with a 60 to 87 percent increase in income. This trend suggests that, one way or another, countries of independent thinkers find a way to rally others to bring their ideas to life.

Contemporary Western society can sometimes seem to take uniqueness to its logical extreme: people pursue personal goals, advance individual careers and strive for independence from others. Yet it is important to remember that humans evolved as a group-living species. Over the course of evolution human adaptations have been such that a person is unlikely to survive without the aid of others. Shared resources, mutual protection and division of labor are all major advantages of belonging to a group.

It is clear that two opposing forces are at work in shaping a person's identity—a need for uniqueness and a desire to assimilate. For any one of us, the identity we settle on satisfies both constraints. But keep this in mind as you go through the rest of your day: it is only by standing out that a person can be outstanding.