With more and more people finding love online, this factoid can prove useful: Namely, your date's profile on online networking sites (such as Facebook) can reveal whether he's actually a narcissist.

Researchers from the University of Georgia gave personality questionnaires to nearly 130 Facebook users and analyzed the content of their online profiles.

What they found is that the number of Facebook friends and wall posts (messages left by the owner of the profile or friends) that a person has correlates with narcissism. Laura Buffardi, a doctoral student in psychology, said this is consistent with how narcissists behave in the real world, with numerous yet shallow relationships.

A self-obsessed Facebook user will boast thousands of friends and update their "status" non-stop. "Sometimes they'll have a famous (Ralph Waldo) Emerson quote, but they'll include quotes from themselves or something flattering someone else said about them," Buffardi said.

And guess what, narcissists are also more likely to choose glamorous, self-promoting pictures for their main profile photos, while others are more likely to use snapshots. So if you see him posting photoshopped, look-at-me pics of himself, he probably has a narcissistic streak.