Jeffrey Kluger describes some of the key traits of narcissistic personality disorder, pointing out that some of our greatest leaders have narcissistic tendencies. Kluger, a senior writer at TIME, is the author of The Narcissist Next Door: Understanding the Monster in Your Family, in Your Office, in Your Bed—in Your World.

Jeffrey Kluger: Narcissism is one of the personality disorders. There are ten personality disorders such as histrionic personality disorder, borderline personality disorder and rigidity and so forth. Narcissism falls into that category and is measured by sort of the presence of the three classic behavioral traits. One is grandiosity, the next is entitlement and the next is a lack of empathy. And all three of these things sort of intuitively describe the narcissist. Grandiosity is a deeply felt belief that you are better than other people, that you're more skilled than other people, more gifted than other people, and also that other people are uneducable as somebody I know who was a narcissist once said uncoachable, the belief that you have so much to teach and other people simply can't learn it.

Entitlement is also self-explanatory. It's the belief that raises, that rewards, that applause, that attention, that love, that romance, that anything it is you want and need you are entitled to receive. Babies have that level of entitlement. It's the reason that babies aren't just frustrated or disappointed when they're denied the cookie or the extra ice cream there want, they're actually outraged by it because they can't believe in their wee baby brains that they're actually being denied something they want. It's the difference between want and need and narcissists don't get it. And the critical, perhaps most destructive of the three elements is lack of empathy. Because for all of us, for nearly anybody, empathy is a break on our behavior; it's a speed bump on our behavior. You see the way you're behaving, you look at other people, you can read it in their eyes and their body language and their voice. You get it intuitively that other people are being hurt by your behavior and you empathize with that and therefore don't do it. Narcissists are sort of anesthetized on that front and as a result they don't have that deterrence to their behavior.

Narcissism, like a lot of a personality disorders, exists on something of a continuum. And in my book I call it lowercase n narcissism all the way up to capital N narcissism. Capital N narcissism is the truly clinical kind; the kind that does go by the acronym NPD for narcissistic personality disorder. And it's for a condition that seems ubiquitous, it actually afflicts in it's clinical sense a small share of the population, perhaps one to three percent of the population has narcissistic personality disorder, which is pretty consistent with the other personality disorders and fairly consistent with anxiety disorders like OCD and phobias as well. The problem is you move down that continuum. And the closer you come to clinical narcissistic personality disorder as you move down the continuum the more destructive your behavior is, even if you're functional. Even if you're moving through society and have a family and have a circle of friends and have a job, you're still the kind of person who's going to get into a lot of scrapes, a lot of dust ups, a lot of confrontent with the people around you because you just don't get that you're not entitled to so much. You just don't get that you're not as good or as great as you think you are.

When you move further down the narcissistic scale you get to the point that narcissism can actually be a very good thing; it can be very bracing; it can be a source or at least a way of expressing creativity. As I say in the book, and I think has given offence to some people but it's not intended to, it's that even our greatest and most humble people, Mahatma Gandhi, Martin Luther King, had to have had narcissistic components to their personality. They gravitated toward attention, they gravitated toward crowds. If we believe that they didn't get a charge out of standing before a crowd of half a million people, or in the case of Gandhi millions, and moving an entire nation with their words, well we don't really understand human nature then if that's what we think of. Of course they got a charge of it but they were equally humble men. They were equally modest men. They understood that what felt good to them, what energized them wasn't all there was to it. Steve Jobs was a brilliantly creative narcissist, he was also something of an abusive narcissist. No slur on his work but he was not a well loved by the people he worked for even though they agreed he was right; even though they agreed most of his criticisms were on point but he expressed them terribly.

Bill Clinton was a self-destructive narcissist, although he's so fatally charming, which is also one of the narcissists' great traits a sort of lethal charisma that we forgave him a great deal. Ronald Reagan I think is a very, very good example of perhaps the most highly functional narcissist who's ever been in, at least in our political system. Even if you don't like Reagan's politics, even if you never voted for him you had to acknowledge the fact that he seemed just like a decent and genial and comfortable and amused and amusing man who enjoyed being inside his own skin, who enjoyed being around other people, who just liked what he was doing in a very uncomplicated way. But again, it was narcissism, healthy narcissism that pushed him into movies, it was healthy narcissism that pushed him into politics.

Paradoxically our most narcissistic president, you would think it would be JFK, you would think it would be LBJ, a lot of people would have thought it was Reagan, our most narcissistic president was Chester A Arthur. He served one unremarkable term in the White House. He had very little to do in that time. It was an era of peace and prosperity. The most he had to concern himself with really was reforming the U.S. Postal Service and figuring out how to spend America's then massive $158 million budget surplus. But, as I say in the book, President Arthur had a whole lot of other things on his mind, such as the 1200 wagonloads of furniture and accessories that he had removed from the White House because they weren't to his liking. And the 1200 wagonloads of new things he had brought in all under the supervision of Louis Tiffany. And yes that means that Tiffany. He owned 80 pairs of pants. He changed his clothes three times a day in order best to display his wardrobe. And he was known in his era as the dude of the White House. Dude precedes our generation by many, many years though we don't think it does.

Among the other high scorers in narcissism were Franklin Roosevelt, which is no surprise given the fact that he thought himself capable of winning four terms and did win four terms. Other high scorers were Lyndon Johnson whose sort of monomaniacal pursuit of the Vietnam War seems consistent with a narcissist's inability to hear criticism or hear that he's doing badly. The least narcissistic president, no surprise, was Calvin Coolidge, silent Cal who came in dead last in the Narcissistic Personality Inventory Scale of presidents. He once famously said I think Americans want a solemn ass as president and I'm going to give them that. So he succeeded in that.

Barack Obama certainly would score high if he were to sit down and take the Narcissistic Personality Inventory. He sought the presidency after only two years in the Senate. He clearly believed that he could achieve high office, he did achieve high office. Unlike some narcissists he doesn't seem terribly comfortable in the public eye, or at least terribly comfortably mingling with people. Now Richard Nixon was profoundly uncomfortable mingling with people. Ronald Reagan and Bill Clinton are profoundly comfortable. Obama certainly seems at ease in a room full of people, he seems at ease in a crowd, he seems at ease one-on-one with people, but at the same time there is a coolness and a detachment to him that a lot of people criticize. So while he's certainly narcissistic, I don't think he is really as far along the narcissism scale as some of the other presidents.

One thing that Al Gore told me one day when I was talking to him about the presidency was very enlightening about all people who either become president or even seek the presidency. This conversation took place in 2008, early 2008 when there were still some constituency in the democratic party hoping he would run for president. And I asked him do you believe that if you came to the conclusion that you were truly the best person equipped to effectuate the kinds of changes that you want to see the country effectuate, particularly say environmental issues, do you believe that you would then have almost a personal obligation to run? And he answered with sort of a laugh and said, "Well, everybody who runs for president believes that." That's the threshold requirement for getting into the race in the first place, the belief that you are the best qualified person for the job.

Directed / Produced by Jonathan Fowler, Elizabeth Rodd, and Dillon Fitton