Everybody’s personality falls somewhere on a spectrum — how outgoing or introverted we are, the number of neurotic quirks we have, or our degree of optimism versus pessimism, for example. Our level of selfishness also falls on a spectrum, with a healthy dose of self-centeredness on one end and extreme personality disorder on the other.
The concept of narcissism goes all the way back to Greek mythology with the eponymous Narcissus, who was so vain that he fell in love with his own reflection and died gazing upon it, unable to look away. In the modern world of psychology, narcissists are people who have a huge ego and idea of entitlement as well as an inflated sense of self-importance. They crave admiration from others but show them no empathy.
According to Psychology Today, that empathy is a crucial indicator of whether someone is simply selfish or a full-blown narcissist. If someone were to theoretically point out a selfish person’s behavior, that person “is likely to genuinely feel remorseful, and might earnestly change his behavior and habits in the future.” But someone who gets mad that he is being criticized, or who just appears remorseful but does not change, might be a narcissist.
“Self-centered people can be empathic,” that publication says. “Narcissists may fake it, but still essentially see others as pawns in their egocentric universe — and fail to make real changes.”
Narcissists also don’t think rules apply to them because they are special, whereas selfish people will have moral boundaries. And while self-centered people want attention from others, narcissists are more likely to ignore what others have to say in a conversation.
Scientific American points out that one established self-test for narcissism evaluates how much people agree with statements like, “I resent others who have what I lack” and, “I wonder why other people aren't more appreciative of my good qualities.” There are also more obvious indicators like, “My feelings are easily hurt by ridicule or the slighting remarks of others,” and, “I easily become wrapped up in my own interests and forget the existence of others.”
For another indicator of how selfish you are, you could also measure your self-control. Research has suggested that selfish people have less self-control because they won’t even consider the feelings of their future selves, and thus are less able to delay their gratification and wait for a better reward down the road than the one presented to them in the moment.
Tremendously self-centered people may also have antisocial personality disorder, the most extreme versions of which are sociopathy and psychopathy. People with these conditions are arrogant, show a lack of regard for the feelings of others or for what is right and wrong, and although they can seem charming, they are highly manipulative and deceitful without guilt or remorse.
“People with antisocial personality disorder tend to ... treat others harshly or with callous indifference,” the Mayo Clinic explains. But they have other troubling signs that cannot be merely confused with selfishness: They usually engage in aggressive, impulsive, irresponsible or risky behavior, often just for the thrill of it. They are highly volatile — a study has shown, for example, that psychopaths are more likely to assault a romantic partner — and often have criminal records. In those cases, with notorious killers like Jeffrey Dahmer and Charles Manson, it seems that self-centeredness is the least of everyone’s worries.