here are some traits as defined by the APS
Pathological Lying
Has no problem lying coolly and easily and it is almost impossible for them to be truthful on a consistent basis. Can create, and get caught up in, a complex belief about their own powers and abilities. Extremely convincing and even able to pass lie detector tests.
Irresponsibility/Unreliability
Not concerned about wrecking others' lives and dreams. Oblivious or indifferent to the devastation they cause. Does not accept blame themselves, but blames others, even for acts they obviously committed.
Manipulative and Conning
They never recognize the rights of others and see their self-serving behaviors as permissible. They appear to be charming, yet are covertly hostile and domineering, seeing their victim as merely an instrument to be used. They may dominate and humiliate their victims.
Callousness/Lack of Empathy
Unable to empathize with the pain of their victims, having only contempt for others' feelings of distress and readily taking advantage of them
Shallow Emotions
When they show what seems to be warmth, joy, love and compassion it is more feigned than experienced and serves an ulterior motive. Outraged by insignificant matters, yet remaining unmoved and cold by what would upset a normal person. Since they are not genuine, neither are their promises.