What study is best used in pathological liars and their relationships?

I am not aware of any specific studies but I can tell you that pathological liars suffer from antisocial personality disorder (also called sociopathy). In relationships, these people are draining and parasitic and should be avoided at all costs. They are experts at charming even the smartest and most intuitive people. In relationships, a sociopath sees a target --someone they can use and exploit. Sadly everyone is a potential target to a sociopath because we all have weaknessess and the sociopath is a master at exploiting a person's weakness for their own personal gain. They lie, lie, lie! I think many believe their own lies but its hard to tell because a real sociopath probably won't admit to it. The net is just brimming with information on this topic. One exceptionally helpful site is www.lovefraud.com. It explains the disorder as well as providing legal/personal advice on how to deal with such people. The site also contains a forum in which victims of sociopaths may share their personal experiences and offer guidance and support to one another. Of course the DSM (Diagnostic and Statistical Manual) is the official source of information for any pathology and should be consulted for a deeper understanding of the pathological liar and his/her interactions with others.