A recent study published from Western Illinois University shows a link between your Facebook activity and the likelihood that you are self-absorbed.
The study results said people who updated their status throughout the day, tagged themselves in photos and have a lot of Facebook friends were more likely to be narcissists.
Mashable.com reported on this and another study, published in 2010, which linked Facebook behavior to self-worth.
The bottom line result said some people turn to Facebook as a way to feel good about themselves or to boost their ego. The study linked self-promotion on Facebook to the desire to be the center of attention and to the extent to which some people will go to get that attention.
Read the Mashable.com article – http://mashable.com/2012/03/19/facebook-narcissism-2/
Read more about the WIU study – http://www.journals.elsevier.com/personality-and-individual-differences/