Five studies, published in 2004 in the journal Personality Processes and Individual Differences, looked at some benefits of narcissism. Hundreds of people participated.

Results showed that narcissists tended to be less depressed, lonely, anxious, and neurotic, and reported greater well-being than people who scored low on narcissism.

"High narcissists may be socially callous, but that is no reason for them not to be psychologically healthy. To use a far-fetched metaphor, the mind of a narcissist is like a sports utility vehicle. It is great to be in the driving seat, but fellow motorists must watch out, lest a collision with this mobile fortress demolish their more humble hatchbacks."

Being moderately narcissistic seems to protect against social anxiety.

Narcissistic adolescents and young adults tend to be more satisfied with life than their peers.

In "Rethinking Narcissism," Harvard Medical School psychologist Craig Malkin gives a definition of healthy narcissism: being able to move "seamlessly between self-absorption and caring attentiveness."

Malkin and a colleague developed the Narcissistic Spectrum Scale, on which two key indicators of healthy narcissism are responding "no" to the statements, "I like to dream big, but not at the expense of my relationships" and "I can rein myself in when people tell me I'm getting a big head."

If you do score high on healthy narcissism, Malkin writes, you're likely to have an easy time giving and receiving emotional support, and to enjoy closeness and emotional intimacy.