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The Polygraph/lie detector is a fraudulent test

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posted on May, 2 2009 @ 08:30 AM
Polygraphy is used plenty these days, by law and recently by employers to detect deception. There is something rather intimidating about the polygraph machine, when you are put in a situation where your honesty is being tested, especially if a serious crime is involved, the polygraph can be rather scary, even if you are innocent.

Your put in a chair with apparatus strapped all around you monitoring skin conductivity, breathing rhythm, blood pressure and heart rate, and you are asked definite closed yes/no questions. All the while you are thinking, "Is the machine going to say I'm lying?" Needless to say, it's a high anxiety situation for anyone.

So is it all that it's cracked up to be? Does the innocent person really have anything to stress about? The worrying answer is yes, the guilty can pass and the innocent can get false failures, so ethically it's become a subject of controversy.

The first thing that should be pointed out is that the polygraph doesn't detect lies or deception, in fact it doesn't detect anything because it's a monitor, it simply shows physiological conditions and whether or not they are changing.

There are 2 types in modern use; the older is the analogue where the readings are scribed onto a piece of rolling paper charting the conditions of an individual over time. The more commonly used today is the computerised form where an individual’s conditions are charted on a computer using certain software.

The lie detection or the pass/fail dichotomy is superimposed onto the recordings by an annalist, it's a conclusion made on the changes in the physiological state of the polygraphed individual. It's essentially based on the theory that lying is more stressful that telling the truth (especially if there is extra stress from a form of jeopardy). Stress affects the sympathetic nervous system - the part of us that is at work in high activity/anxiety situations like in flight or fight situations.

The problem arises because any emotion significantly strong enough to induce a level of stress will register these changes, whether it be anger, paranoia, embarrassment, surprise or fear, anything that to the individual is particularly an area of sensitivity. Fact is, anything that will get your heart racing will register on the polygraph, even arousal will register.

The only thing that one can accurately conclude from polygraph readings is the stress of an individual being tested - not a level of deception. It is for this reason that the biggest criticism against Polygraphy is false positives (of deception) in innocent individuals that occur merely from the stress of the situation or the anxiety from considering the ramifications of failing a test and being falsely convicted. In other words, the less confident you are in your answers, the more likely you will fail.

All people being unique will register differently with "truthful" answers and "deceptive" answers, so there are no universal signatures for either. A "truthful" register and a "deceptive" register must be established for individuals in order to determine either in questioning. This is attempted in the method of questioning, asking relevant questions and irrelevant questions. On the irrelevant questions, one is asked a question by the annalist, that is almost certainly going to be a lie, like "Have you ever stolen from a loved one?" People just say ‘no’ when it’s just one of those things that most people have done.

Another problem is ‘Counter Measures’, where an individual can alter his or her registers consciously, leading to inconclusive results. Anything that can be used to alter your breathing, sweatiness, blood pressure or heart rate when used in conjunction with an irrelevant question will render the polygraph useless; conscious ‘deceptive’ results are pretty much indistinguishable from real ‘deceptive’ answers.

Good counter measures are consciously breathing deeper and/or more erratically; tensing muscles, or thinking about scary or exciting situations (a striptease perhaps). Anything you can think of to alter your condition, people who meditate and have good control over their being are exceptionally good at this.

Since there is no real way to say what is and isn’t a deceptive answer for sure, it becomes unscientific because it is just too inconclusive.

Proponents of the polygraph often parrot the assertion that the poly graph is “90 – 95% accurate” when real enquiry does not support this at all.

The American Polygraph Association says this about the validity of polygraph tests.

The 80 research projects listed, published since 1980, involved 6,380 polygraph examinations or sets of charts from examinations.
Researchers conducted 12 studies of the validity of field examinations, following 2, 174 field examinations, providing an average accuracy of 98%. Researchers conducted 11 studies involving the reliability of independent analyses of 1,609 sets of charts from field examinations confirmed by independent evidence, providing an average accuracy of 92%. Researchers conducted 41 studies involving the accuracy of 1,787 laboratory simulations of polygraph examinations, producing an average accuracy of 80%.
Researchers conducted 16 studies involving the reliability of independent analyses of 810 sets of charts from laboratory simulations producing an average accuracy of 81%. Tables list the authors and years of the research projects, which are identified fully in the References Cited.
[American Polygraph Association]


In 2003, the National Academy of Sciences (NAS) issued a report entitled “The Polygraph and Lie Detection”. The NAS found that the majority of polygraph research was " Unreliable, Unscientific and Biased" (quote). The NAS study identified 57 of the 80 odd research studies that the APA relies on, to come to their conclusions. These studies concluded that a polygraph test regarding a specific incident can discern the truth at “a level slightly greater than chance, yet short of perfection”.

[Go to next post...]

[edit on 2-5-2009 by Welfhard]

posted on May, 2 2009 @ 08:31 AM

There is a lot of criticism over these 80 – 90% figures (notably lower that the previous 90-50% assertion).

A physician biodefense researcher at the weapons lab, Alan Zelicoff has led opposition to the polygraph there, saying that for screening purposes, the device's measures — pulse, blood pressure, breathing and sweating — reveal deception about as well as a coin flip. He likens the polygraph to a defective medical test, one whose high false-positive rate, depicting honest people as liars, makes it unreliable as a diagnostic tool. Last year, Attorney General John Ashcroft estimated the false-positive rate of polygraphs at 15%, about a one-in-six chance, at a news conference.
[USA Today]

…in some studies, researchers may toss "inconclusive" tests results, which if added back in, may lower the accuracy rate for detecting deception to the 70% range. Critics like retired FBI scientist Drew Richardson suggest the high accuracy rates reported in some studies result more from the high likelihood of guilt among those tested — criminals or study volunteers who act as faux criminals.
[USA Today]

"A big problem is that it's not really a test of anything," says psychophysiologist William Iacono of the University of Minnesota. He agrees the polygraph can measure physical reactions, but beyond that, nobody knows how the nervous system acts when it is lying.
[USA Today]

People who don't believe in the polygraph may be more likely to fail tests, he says. Their disbelief and non-responsiveness may look like deception.

The Observer-Expectancy effect (OEE) will do this to the test. Anyone who will be tested in a criminal investigation context or, indeed, any accusatory context will likely expect the so-called “lie detector” to detect the les, producing more stress when one does actually lie. However, this stress will disappear in an individual who has no expectancy that the machine will detect deception or guilt, removing the stressor and the resultant registering. Although this situation may prove worse for the individual being tested because a lie on a control (irrelevant question) will likely not provide much response and answers to relevant questions will appear likewise; in this case, annalist may conclude the individual is being deceptive.

Despite all of it’s faults and unreliability, there is a very good reason that it is used by law enforcement. There is a strong cultural perception of the polygraph, due partly to it’s nickname ‘Lie Detector’ and the “trained” specialists of Polygraphy saying that it’s “90 - 95%/95 – 99%” accurate. It’s widely believed that the polygraph is unbeatable – “not even Mythbusters managed to fool it, it must be solid!” - and under that impression, the average ignorant person, if guilty of a crime, especially a serious crime, may spontaneously confess. The polygraph can be a major toll for applying pressure on suspects and if a guilty person passes the polygraph test, they are hardly likely to turn around and confess, so what’s going to make them?

Please note, I am not advocating crime, or trying to tell you how to get away with crimes! I am trying to explain that no matter what the proponents say, the polygraph is not accurate, it's not scientifically base and it does not detect deception or lies. This is junk science and should be treated as such.

Some relevant vids and links for you all… - Be sure to look at their Ebooks, they are all free - especially 'The Lie Behind the Lie Detector'. (1mb)'s youtube channel

USA Today: Telling the truth about lie detectors

Again, please note, I am not advocating crime, or trying to tell you how to get away with crimes; just that this is junk science.

[edit on 2-5-2009 by Welfhard]

posted on May, 2 2009 @ 09:23 AM
It's not much different from dosing, actually. The tester is subjective, so the results are subjective.

I beat a polygraph one time without any "special techniques", just a sincere tone of voice and enough real facts to give my red herrings a plausible ring. I learned that system from "Garbo" (Google garbo and D-Day).

posted on May, 2 2009 @ 09:42 AM
Someone stated the failure rate for employment for the CHP in California using the polygraph is 50%.

posted on May, 2 2009 @ 09:49 AM
reply to post by 38181

Funny that, huh..

posted on May, 2 2009 @ 09:56 AM
Actually the polygraph is an extremely accurate machine.

The reason it was dubbed inaccurate by the court system is the judges were worried that they would lose their jobs at such an invention.

And btw, it is fool proof. It takes in account that your nervous and sweating. it sets a baseline and goes by that.

You have heard rumors that people have beaten it. Only one or two people have beaten it. And they were highly trained russian operatives who trained for months to learn to beat the machine.

So some joe smoe can't walk up and outsmart it.

You have to remember, if society did dub the polygraph accurate, a lot of people wouldn't have jobs, so there is a reason there is so much dis info out there.

[edit on 2-5-2009 by nixie_nox]

posted on May, 2 2009 @ 09:58 AM

Originally posted by Welfhard

Your put in a chair with apparatus strapped all around you monitoring skin conductivity, breathing rhythm, blood pressure and heart rate, and you are asked definite closed yes/no questions. All the while you are thinking, "Is the machine going to say I'm lying?" Needless to say, it's a high anxiety situation for anyone.

I find it very difficult to answer any question with a straight 'yes' or 'no' (unless someone's asking me if I want a cup of tea). Usually my answer would be something like 'yes, but not always' or 'no, but sometimes....'

I find personality tests quite difficult, because I want to say 'yes' or 'no' 'but it depends on the circumstances at the time'.

Let's say in real life someone asked me if I liked chocolate but required a yes or no answer. I'd be wondering why they were asking, were they perhaps thinking of offering me some? Now the answer is 'yes - I love it' BUT as a chocoholic I am not allowed to eat it, so should I say 'no' so as not to have someone going out of their way to get some for me?

So, after all the waffle, I can quite understand how a polygraph could throw up some wrong results.

If you're not allowed to answer a question with any details or explanations it must be extremely distressing for people.

And some people even haul their partners onto TV programmes to take these tests to prove themselves not guilty of cheating. Try telling a studio audience and an outraged partner that the reading is wrong if it says you're a liar. (Not to mention the relief if you're guilty and you manage to get away with it).

Is there perhaps a standard style of questions so that if the analyst got a dubious reading for one question they could probe further and get more consistent readings with subsequent questions?

posted on May, 2 2009 @ 09:58 AM
reply to post by nixie_nox

Actually the polygraph is an extremely accurate machine.

yes but it doesn't really do anything like detecting lies. It cant tell you what a person's mind is doing, just what their body is doing. The polygrapher is the one who decides if a person is being truthful or not, and they are basing that conclusion on a machine that has no way of separating deception from any other emotion.

You have to remember, if society did dub the polygraph accurate, a lot of people wouldn't have jobs, so there is a reason there is so much dis info out there.

Are you saying the ends justify the means? All the false positives/negatives and incrimination of innocent people are justified.

[edit on 2-5-2009 by Welfhard]

posted on May, 2 2009 @ 10:02 AM
reply to post by berenike

They phrase the questions so you only need to give yes and no answers. One reason it takes so long.

Instead of... are you friends with this person? which you may be grey to you.

It would be, have you met this person? Had dinner with them? Met them more then once? only at work?

then they narrow it down.

A good polygrapher does that.

posted on May, 2 2009 @ 10:30 AM
reply to post by nixie_nox

That's what I wanted to know. I mean if the analyst asked you if you murdered someone, you'd say 'no' even if you'd done it.

If, on the other hand, they said 'killed' instead of 'murdered' and you thought the next questions were going to ask whether or not it was an accident, or self-defense, you might be more inclined to be truthful.

Probably not a great example

[edit on 2-5-2009 by berenike]

posted on May, 2 2009 @ 12:52 PM
Polygraph machines are so unreliable, they are inaccurate and rely on the interpretation of the results by the researcher... a mine field of variables.

I believe research has found that when a subject lies the p3000 brainwave is measureable. Can't remember who found this out but it is supposed to be a very accurate way of conducting a truth test.

posted on May, 3 2009 @ 03:23 AM
Polygraph tests are not considered valid evidence in the American court system. Some police agencies may still use it, but they can't present it in court. Some business probably use it, but really, as private enterprises, they can do whatever they like, in that regard, seeing as you could just quit if you didn't like it.

It gives a lot of false positives, though, so I don't think it's really something that should be used.

posted on May, 3 2009 @ 04:36 AM
One that is common her in calif is the pen or pencil "honesty" or "personality" test.

Companies use them for four reasons. one is to test the possible employees to see if they will put up with the test.
Some don't and companies don't want employees that question authority.

Two is that many of these pen and pencil tests will give away things like the religious views or sexual orientation of the person applying.
In addition to issues of discrimination and privacy, psychological tests are treated like medical tests when they elicit answers that suggest a mental disorder or impairment (see below). This fact puts the test clearly within the purview of the Americans With Disabilities Act (ADA) and all of its restrictions.

Three and the best reason most companies use them is to ask questions that they can not legally ask a applicant in a interview.

And the last is as a legal means to use as a reason not to hire someone whether they pass or not.

The honesty test? A priest failed the one he was given. His "mistake?" Forgiveness for past errors. In filling those out, the candidate to get the best marks was to send all shoplifters to jail and have their names published prominently in the newspaper. The priest mistakenly marked, "everyone makes mistakes." That was HIS mistake.

Another case i am aware of involves Sister Terressa, a nun from Minneapolis, who was rejected for a part time job with B. Dalton Bookstores because she failed the written honesty test (the Reid Report). She was told that her score was the worst they had ever seen

[edit on 3-5-2009 by ANNED]

posted on May, 4 2009 @ 09:12 AM
I personally put a lot of faith in these Polygraph machines... as well as the Software version... these two system working together is a really tough formitable foe... if you are trying to deceive.
If I have anything to say about Rights in this land. this is one the Public has got to have... as well as Private Citizens keeping them honest.
we all know you can not run a honest government so lets get that out right away. but there are degrees of Treason. and the Veterans of this nation - have the security clearances as well as the experience .... and with the Polygraph and FBI on the Citizens side... the vision of America could be realized. so I recommend Polygraph for anyone accepting Public funds including suppliers and the like... we limit profit on government contracts to a percentage... instead of a kick back kind of system we have... 10 million to build a plant to produce $600 hammers... and no one profited... excuse me... our nation was founded with this principal.... WHO PROFITTED... some how they stopped asking this question in court and now they just want to know the Patsy...

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