posted 09-11-2004 08:41 PM
It's a myth, and there is science to back that up. (Most people don't even know what a "sociopath" is since the DSM-4 has watered it down to "anti-social personality disorder" (or APD), which about 80% of criminals qualify for. Sociopathy, or psychopathy, is diagnosed using Hares Psychopathy Checklist.)
Let me quote Raskin and Honts from their chapter in Murray Kleiner's "Handbook of Polygraph Testing."
"Careful laboratory and field research has clearly demonstrated that poor socialization and psychopathy do not reduce accuracy of comparison question tests."
"The extensive scientific literature demonstrates that polygraph techniques are highly effective in detecting deception in poorly socialized and psychopathic individuals, but highly socialized individuals and even psychopaths may be subject to false positive errors (Honts et al., 1985; Patrick and Iacono, 1986)."
There are several studies cited in the chapter if you are interested. (Keep in mind Iacono is usually testifying against polygraph.) There is also evidence to support GKTs, CITs, POTs, or whatever you want to call them (recognition tests), are effective on psychopaths as well.
The reason people teach such foolishness is becasue they have a very narrow uderstanding as to why a guilty person / liar might react physiologically. They think that because a person has no guilt feelings about the crime, he will not be concerned about the questions during a polygraph exam, but keep in mind psychopaths are generally highly intelligent. They know they don't want to get caught - and go to jail, so they should fear the consequences of getting caught, which should result in reactions to the relevant questions.
Psychologist Paul Ekman in his book "Telling Lies" (which I say is a must read if your serious about detecting deception) discusses what he calls "duping delight," which is the thrill some get from fooling (by lying) others, which could also result in physiological responses.
There are other reasons why a psychopath might react, but your on your own from here.
Much of what is taught today in interview and interrogation classes is the opposite of what science tells us. E.g., many believe an increase in hand and finger movements during deception is a "clue" to deception when science tells us the opposite is true. i.e. a decrease is your cue.
We dump all over voice stress - and rightfully so - but we peddle the same garbage - in a different package - in many of our interview and interrogation courses. I'd be curious to know what your instructors based their opinions on. It wasn't the scientific literature, which would make me wonder where the rest of their material came from.
By the way, the only scientific studies I've seen show police officers - including polygraph examiners - are no better than chance at recognizing deception. (Untrained college students often do better - about 55%.) The exception is the Secret Service. They usually fair about 60% or better, but nobody is sure why. The irony is, the police - and I am one - are usually much more confident in their wrong decisions.
The good new is, according to Aldert Vrij (another must-read), you can learn to detect deception via verbal and non-verbal behavior if you know what to look for. (And, some people are just naturals. They drive the psychologists crazy, because they (the psychs) can't figure out what the detectors are basing their decisions on, but it's probably a number of things.)
I've rambled enough, but like I said above, it's a myth.
Maybe you can email them and set them straight?
Polygraph Place Bulletin Board
posted 09-11-2004 12:21 PM
