Saturday, October 29, 2005

Can a Psychopath Fake a Polygraph?

I went to a really great birthday party for a friend the other night. The guests were mainly in law enforcement and the chatting alternated between how people felt about their work to politics. A retired FBI polygrapher and I talked about the polygraph test and whether or not it could be faked (I know, it's a party and I should stick to talking about cheese dip but I hate small talk and I can't eat cheese dip due to my heart healthy diet). The polygrapher was adamant that the polygraph test was accurate but I remained a skeptic.

For the most part, psychologists believe there is little evidence to show that polygraphs are accurate lie detectors. I also pointed out to my colleague that psychopaths who show few physiological responses to lying might be able to pass a polygraph. His view was that we have so few psychopaths in our midst that he was unlikely to encounter one. This could not be further from the truth. Of course, as a forensic psychologist, I encounter more than my fair share (so my views may be skewed), but psychopaths are more prevalent in our normal society than most people, even in law enforcement, realize.

In fact, Dr. Robert Hare, the author of Without Conscience, estimates that there could be as many as 100,000 psychopaths in New York City alone--and at least 2 million in North America. Given that psychopaths--those without empathy for others who are typically con artists and users--have a higher rate of violent crime--it is very probable that my polygrapher friend would have numerous opportunites to encounter a psychopath in his work. I just wonder how many false negatives (a person is lying but looks like they are telling the truth) have been released based on erroneous results and how many innocent people who looked guilty have been charged after taking a polygraph.

It is an unsettling question and one that calls for further research into the use of the polygraph as a tool for spotting deception. There is work being done on functional brain imaging which shows that during lying, there is more activation in five brain regions. This research has not yet advanced to the stage where it can be used for real world application.

By the way, in case you were wondering about the large number of psychopaths in NYC, my guess is that psychopaths like to live in big cities where they can get away with their crimes and abuses. In a small town, it is likely that someone would know you and let others know about your bad deeds. That would make it harder to find victims.

15 Comments:

Blogger Helen said...

Hi allicent,

That is a good question--I doubt that they are--I know cases of young girls accusing fathers and relatives of sexual abuse out of anger but I have not heard of any of them taking a polygraph test. As I noted in a previous post--there is little consequence, it seems, for accusing someone of sexual abuse so maybe no one bothers to care if they are telling the truth or not.

6:15 AM, October 30, 2005  
Blogger Albatross said...

I was subjected to a polygraph once. Some stock was going missing at the club where I worked some years ago, and the manager suspected an employee. He made every employee who worked a certain night take the polygraph in an attempt to flush out the pilferer.

It didn't work. The thief was never caught, and a couple of people (myself included) who really did not know who the thief was were pegged as lying. I found out later who was stealing from the club (he passed the exam, by the way), but I did not know at the time of the test, and the test indicated my statements were suspect.

To sum, my personal experience convinces me that polygraphs do nothing more than measure how nervous a person is. They are not "lie detectors", and I hope my livelihood and my freedom never depend on the results of one.

8:50 PM, October 30, 2005  
Anonymous Anonymous said...

I've never been convinced that polygraphs really work. It seems to be one of those "scientific processes" that at one time were new and shiny - thus making people think it "must" be right... hey it's science! And because it was accepted early on it's become an indelible part of the system - not questioned. Rather scary.

11:24 PM, October 30, 2005  
Blogger Chap said...

I took only one polygraph, about twenty years ago, for a restaurant job. I figured out how to break the thing about five minutes into it. The secret? To "lie", think "OMG I'M GOING TO BE CAUGHT" and the attendant internal freakout; for everything else, calm, cool water. I hear others use a mild tranquilizer and a pin in the shoe to step on if they have to "lie" to calibrate the machine. Alternatively, one can completely be freaked out and invalidate the whole test.

And if one believes what one is saying, or if one cannot feel that "I"M CAUGHT" feeling, then one will not make the polygraph needles wiggle.

The "lie detector", though, is an intimidating process and this is valuable for some organizations.

By the way, the restaurant chain imploded when the cocaine ring inside finally ate enough of the organization. The coke fiends apparently went through this same process...

3:09 AM, October 31, 2005  
Anonymous Anonymous said...

One need not be a psychopath or go to spy school to fool the polygraph. All that is needed is an understanding of the trickery behind the procedure.

While examinees are told that all questions must be answered truthfully, denials in response to certain questions -- called "control" questions – are assumed to be less than truthful. One common control question is, "Did you ever lie to get out of trouble?" The polygrapher steers the examinee into a denial by warning that anyone who would do so is the same kind of person who would commit the crime that is under investigation and then lie about it. But secretly, it is assumed that everyone has lied to get out of trouble.


The polygrapher scores the test by comparing physiological responses to these probable-lie control questions with reactions to relevant questions such as, "Did you shoot John?" If the former reactions are greater, the examinee passes; if the latter are greater, he fails.

The "test" also includes irrelevant questions such as, "Are the lights on in this room?" The polygrapher falsely explains that these questions provide a "baseline for truth," but in fact, they are not scored at all! They merely serve as buffers between pairs of relevant and control questions.

Scientists agree that this simplistic methodology is without validity. The truthful are often falsely branded as liars while the deceptive pass through. Perversely, the more honestly one answers the control questions and exhibits less stress when answering them, the more likely one is to fail. Conversely, however, liars can beat the test by covertly augmenting physiological reactions to the control questions. This can be accomplished by doing mental arithmetic, thinking exciting thoughts, altering one's breathing pattern, or simply biting the side of the tongue.

For more on polygraphy, visit AntiPolygraph.org, a non-profit, public interest website dedicated to exposing and ending waste, fraud, and abuse associated with the use of lie detectors.

6:14 AM, October 31, 2005  
Blogger Helen said...

To George Maschke:

Thanks for the link--I have read this site before and it does have some valuable information. From what I have heard, one of the reasons law enforcement likes suspects to take a poygraph is that they may make an admission or say something during the test that will help in a case--that appears to be the extent of their usefulness.

6:43 AM, October 31, 2005  
Anonymous Anonymous said...

Helen,

If the retired FBI polygrapher you met was by any chance Kendall Shull, should you happen to meet him again, you might ask how he managed to "re-interpret" Los Alamos scientist Wen Ho Lee's polygraph results, which three senior Department of Energy polygraphers scored as passing (with a very high score), to "inconclusive, if not deceptive." For background, see New Info on Wen Ho Lee's Polygraph Interrogations.

7:52 AM, October 31, 2005  
Anonymous Anonymous said...

I lied on a polygraph, and passed; as did all of my fellow employees. I worked at a place where the mgmt was ripping off the parent corporation, and the corp had a policy that all employees had to take a polygraph every 6 months. Before you would go to a polygraph, the union steward would tell you, (paraphrasing) "relax, the polygraph can't tell anything, they count on you being nervous and giving yourself away. Polygraphs don't work." I passed four times. All my co-workers passed also. No one was ever sacked on the basis of a polygraph when I worked there, and theft was rampant.

10:33 PM, October 31, 2005  
Blogger Helen said...

Hi me,

I did a show on the Lillelid murders for City Confidential on A& E--that was a 1997 mass murder in Green County--perhaps that is the one you saw? My email address is on my home page but I will give it to you drhelen@violentkids.com

8:12 AM, November 03, 2005  
Blogger Helen said...

Hi me:

Sounds like they recycled the Lillelid case--they often do that with these shows. I did a documentary on the murders if you are interested--go to www.sixthemovie.com and watch the trailer. Jason Bryant was the youngest in that group--14 at the time of the murders and I believe that he was one of the shooters but not the only one. I was told that Joe Risner participated and I actually think that all of the kids might have--given the number of shots etc. Check out my website for more.

6:50 AM, November 04, 2005  
Blogger Karasoth said...

Hey Dr. Helen just found your blog....

Aldrich Aimes, and every other mole in our nations intelligence agency passed the polygraph. And passed it under the same technique a Union steward put to his employees.

To me if it fails with every single mole then it can't be accurate.

11:28 AM, December 03, 2005  
Blogger unfuel the planet said...

so you mean to say the more the person is confident, the more likely he is to fake the polygraph test

10:26 AM, July 01, 2006  
Anonymous Anonymous said...

This information is very comforting to me. My 5 yr old daughter is currently in therapy at Children's Hospital for sexual abuse by her father - abuse that began when she was not quite 3 yrs old. He recently passed a polygraph, but I can't believe he's innocent because of all the things she has told me he's done to her. He's an accomplished liar, alcoholic and has never once been sorry for the things he did to us as a family. I am continuing to fight to keep him away from her even though the system is letting me down.

2:46 AM, January 31, 2007  
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3:32 AM, April 28, 2007  
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