Narcissism is a personality disorder, characterised by "a pervasive pattern of grandiosity, need for admiration, and a lack of empathy" (DSM IV-TR). Narcissists have an exaggerated sense of self-importance, believe they are special and unique, have fantasies of unlimited success and require excessive admiration from others. There are more symptoms than this,but I'm sure you get the point. A new study has analysed facebook profiles to see if untrained strangers can detect narcissists.