I’ve always believed that you could learn everything you needed to know about a person by asking them who their favorite Beatle was. To back up the efficacy of this bulletproof psychological profiling tool, there are several online Beatle personality tests.  I mean really, if you can’t build an online quiz from it, how valid can a psychological tool be? I, personally, am primarily a John Lennon, with George Harrison undertones. But for the test to work, you actually have to know the Beatles on a fairly intimate level, and their status as a cultural baseline is regrettably eroding.

Now, you could use a more standard but much less interesting approach; say a Myers-Briggs personality sorter, or the “colors” test. I seem to bounce back and forth between “INFJ” and an “INTJ.”

But a recent paper by Ashwini Nadkarni and Stefan Hofman (both from Boston University) in the Journal of Personality and Individual Differences offered a more timely way to sort out the extroverts from the introverts (and the neurotics from the narcissists). It seems our usage of Facebook may provide a remarkably accurate glimpse into who we are.

For example, in their review of previous studies, Nadkarni and Hoffman found that people with neurotic tendencies like Facebook’s Wall, while those less neurotic prefer photos.

Several columns back I bemoaned the fact that the more we use social networking, the less social we seem to become. It appears that wasn’t just my perception. A 2009 study by E.S. Orr et al discovered that shy people love Facebook and spend way more time on it than non-shy people.  Ironically, for all the time they spend Facebooking, their friend networks are much smaller than their more gregarious but less-Facebook-engaged counterparts.

Narcissists also spend a higher-than-average amount of time on Facebook — over an hour a day.  They use the social site to promote themselves through profiles and photos. Conversely, multiple studies have shown than many Facebook fans use it to pump up low self-esteem. Through self-promotion and validation through virtual connections, they’ve found a kinder, gentle and more accepting world than the one that lies outside their bedroom door.

Studies have found that more socially awkward Facebook users have found that the less intense and demanding connections formed online can actually help them expose more of their personalities than they can in a more typical social environment. Some are more themselves on Facebook than they are in the real world. It’s not really creating a new persona, but rather exposing the one you’ve always possessed but felt too fragile to put out there in your day-to-day interactions.

Finally, what does it say about you if you use Facebook only sparingly or not at all? Are you hopelessly disconnected? Not at all. The more individualistic you are, the more goal-oriented you are and the more disciplined you are, the less you tend to use Facebook. Ironically, if this matches your personality type and you do use Facebook at all, you probably have a very healthy network of friends. I don’t know where I fall on the scale, but I probably spend less than an hour a month on Facebook — and for some reason, I seem to have a network of close to 400 friends.

Maybe it’s my irresistible INFJ/John Lennon-like qualities. I hope that doesn’t sound too narcissistic.