Narcissism has long gotten a bad rap. Its unseemly reputation dates back at least to ancient Greek mythology, in which the handsome hunter Narcissus (who undoubtedly would be gloating over his present-day fame) discovered his own reflection in a pool of water and fell in love with it. Narcissus was so transfixed by his image that he died staring at it. In 1914 Sigmund Freud likened narcissism to a sexual perversion in which romantic attraction is directed exclusively to the self. Contemporary views are hardly more flattering. Enter the words “narcissists are” into Google, and the four most popular words completing the phrase are “stupid, “evil,” “bullies” and “selfish.”

In 2008 psychologist Jean M. Twenge of San Diego State University and her colleagues found that narcissism scores have been climbing among American college students in the U.S. for the past few decades. Although the data are controversial, these scholars argue that we are living in an increasingly narcissistic culture.

Some of the opprobrium heaped on narcissists is surely deserved. Yet research paints a more nuanced picture. Although narcissists can be difficult and at times insufferable, they can also make effective leaders and performers. Moreover, because virtually all of us share at least a few narcissistic traits, we may be able to learn something about ourselves from understanding them.

Calling All Narcissists

Psychologists conceptualize narcissism as extreme self-centeredness. Of course, we can all be a bit self-focused at times, but for narcissists the self is an overriding concern. In the laboratory, psychologists often measure narcissism using the Narcissistic Personality Inventory. On this questionnaire, individuals pick one statement from pairs such as “I prefer to blend in with the crowd; I like to be the center of attention” and “I am no better or worse than most people; I think I am a special person.” Their score reflects how narcissistic they are.

Some items on the test reflect a truth dating back to the Greeks: narcissists are obsessed with their looks. In 2008 Washington University psychologist Simine Vazire and her colleagues found that such individuals tend to wear expensive clothing and spend a lot of time preening. Data also confirm that narcissistic people like to talk about themselves. In 1988 psychologists Robert Raskin of the University of California, Berkeley, and Robert Shaw of Yale University found that in taped monologues, narcissistic undergraduates were significantly more likely than other students to use the word “I” and less likely to use the word “we.”

In extreme forms, narcissism can become pathological. In the latest edition of psychiatry's bible, the Diagnostic and Statistical Manual of Mental Disorders, narcissistic personality disorder (NPD) is marked by an excessive sense of self-importance, unrealistic fantasies of success, and intense envy of others' accomplishments. People with NPD are also convinced they deserve special treatment. For example, they may be enraged that they need to wait on line at a restaurant behind other “lesser” people.

Increasing evidence suggests that the NPD diagnosis is actually a mix of two flavors. Grandiose narcissism is the flamboyant, boastful form that probably characterizes both malignant leaders such as Benito Mussolini and Saddam Hussein and highly venerated figures such as General George S. Patton. The lesser-known “vulnerable” variety of self-devotion afflicts more reserved, fragile individuals who may resemble the self-effacing and thin-skinned characters portrayed by Woody Allen in his films.

No one really knows what causes the intense concern with the self that narcissists display. In one theory, they are compensating for low self-esteem by becoming egotistic. Yet this intriguing conjecture has weak scientific support, and another theory suggests that only vulnerable narcissists lack a sense of self-worth.

The Mirror Has Two Faces

Narcissists routinely wreak havoc in everyday life. In a study published in 2004 psychologist W. Keith Campbell of the University of Georgia and his colleagues showed that narcissism is linked to overconfident but rash decision making, such as making unwise bets, and earlier work by Campbell's team tied narcissism to infidelity. Narcissists are also prone to aggression, especially following insults, as a 1998 study revealed. Brad J. Bushman, now at Ohio State University, and Roy F. Baumeister, now at Florida State University, reported that narcissistic college students were more likely than others to retaliate with a loud blast of noise against another “subject” (a confederate of the experimenters) who had derogated an essay they had written. The negative feedback, the authors reasoned, was a threat to their egos.

Even greater damage can stem from the clinical disorder. In 2002 psychologist Paul Nestor of the University of Massachusetts Boston found that individuals with marked features of NPD are at risk for violence and for antisocial personality disorder, a condition that is tied to crime and other irresponsible acts. Self-destructive behaviors may also result from the despair highly narcissistic people feel when others stop noticing them. In a 2009 study a team led by psychologist Aaron L. Pincus of Pennsylvania State University associated features of pathological narcissism with suicide attempts. Vulnerable narcissists may be in particular danger of hurting themselves. Data from 2011 suggest that vulnerable, but not grandiose, narcissism is linked to suicidal thinking, self-harm and emotional distress.

Yet narcissism may be a double-edged sword. A 2009 investigation led by psychologist Amy B. Brunell of Ohio State University at Newark found that narcissistic individuals readily emerged as leaders in group discussions, and among students enrolled in a graduate business program, narcissists were likely to rise to top positions. These outcomes agreed with an earlier study in which psychologist Ronald J. Deluga of Bryant University asked presidential experts to rate U.S. chief executives on a scale of narcissism. Presidents judged to be more narcissistic were rated by an independent group of historians as particularly effective, charismatic and creative. (Narcissism in a leader may sometimes turn off potential followers, however. Psychologist Timothy A. Judge of the University of Florida and his collaborators found that narcissistic students in management programs tend to perceive themselves as better leaders, but others judged them as worse.)

Narcissists' advantages extend beyond leadership, however. In a study published in 2011 psychologist Peter D. Harms of the University of Nebraska–Lincoln and his colleagues showed that narcissistic individuals excelled in simulated job interviews, in part because they were skilled at self-promotion. These findings may dovetail with 2006 results from researchers at the University of Southern California who found that celebrities' narcissism scores exceeded those of the general population.

There is no known effective remedy for narcissism in any of its forms. Yet recognizing that these highly self-centered people probably differ from us in degree rather than kind may give us more empathy for them. If a narcissist is mistreating you, here is a strategy for handling the situation: find a way to be assertive while assuaging his or her sensitive ego.

Although the extreme self-promotion of grandiose narcissists can be dangerous, such self-focus in moderate doses may be advantageous when it comes to professional success and leadership. In this respect, we may have a thing or two to learn from those who see themselves at the center of the universe.