Pathological liars lie for their own benefit, to save their own hide; they do not care a whit about anyone except themselves. Pathological liars are lacking empathy; and the lacking of empathy is called psychopathy.
Psychopathy is a personality disorder characterized by an abnormal lack of empathy combined with strongly amoral conduct, masked by an ability to appear outwardly normal.
Researcher Robert Hare, whose Hare Psychopathy Checklist is widely used, describes psychopaths as “intraspecies predators” as does Simon.
Elsewhere Hare and others write that psychopaths “use charisma, manipulation, intimidation, sexual intercourse and violence” to control others and to satisfy their own needs.
Hare states that: “Lacking in conscience and empathy, they take what they want and do as they please, violating social norms and expectations without guilt or remorse”. He previously stated that: “What is missing, in other words, are the very qualities that allow a human being to live in social harmony”
According to Hare, psychopaths are glib and superficially charming, and many psychopaths are excellent mimics of normal human emotion; some psychopaths can blend in, undetected, in a variety of surroundings, including corporate environments.
According to some, there is neither a cure nor any effective treatment for psychopathy; while psychopaths who undergo traditional talk therapy only become more adept at manipulating others.
http://en.wikipedia.org/wiki/Psychopathy
[This information, and much more about psychopaths, can be found in a hospital medical library.]
Describes my experiences to a T.