I've heard this too but still do not understand how a sociopath can pass a lie detector test. Do they convince themselves that they are telling the truth? In the same token, does that mean that an innocent nervous person could also fail? It seems hardly worth the effort for false readings either way. So much for that theory.
I found this explanation of a sociopathic personality...interesting.
http://www.mcafee.cc/Bin/sb.html
Profile of the Sociopath
This website summarizes some of the common features of descriptions of the behavior of sociopaths.
Glibness and Superficial Charm
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.
Grandiose Sense of Self
Feels entitled to certain things as "their right."
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.
Lack of Remorse, Shame or Guilt
A deep seated rage, which is split off and repressed, is at their core. Does not see others around them as people, but only as targets and opportunities. Instead of friends, they have victims and accomplices who end up as victims. The end always justifies the means and they let nothing stand in their way.
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.
Incapacity for Love
Need for Stimulation
Living on the edge. Verbal outbursts and physical punishments are normal. Promiscuity and gambling are common.
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.
Poor Behavioral Controls/Impulsive Nature
Rage and abuse, alternating with small expressions of love and approval produce an addictive cycle for abuser and abused, as well as creating hopelessness in the victim. Believe they are all-powerful, all-knowing, entitled to every wish, no sense of personal boundaries, no concern for their impact on others.
Early Behavior Problems/Juvenile Delinquency
Usually has a history of behavioral and academic difficulties, yet "gets by" by conning others. Problems in making and keeping friends; aberrant behaviors such as cruelty to people or animals, stealing, etc.
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.
Lack of Realistic Life Plan/Parasitic Lifestyle
Tends to move around a lot or makes all encompassing promises for the future, poor work ethic but exploits others effectively.
Criminal or Entrepreneurial Versatility
Changes their image as needed to avoid prosecution. Changes life story readily.
