To pass or not to pass, polygraphs are the question

Does Misty continue to fail polygraphs because she is lying? Or is there another reason she can't pass the test?

Here's an interesting article: "Does the polygraph test, otherwise known as the lie detector test, work? Melvin Foster may not think so. Back in 1982, after profilers thought a taxi driver might be the Green River Killer, they targeted Foster as a suspect, partly because he drove a taxi. He generously agreed to a polygraph test, which he failed.

The problem was, he was innocent.

Meanwhile, over a period of about two to three years, the Green River Killer murdered four dozen or more women near Seattle and Tacoma, Washington." <snipped>

http://www.articlesfactory.com/articles/government/the-polygraph-test-does-it-work.html

I've been looking for links that discuss people who fail polygraphs when they are innocent and why does that happen? I haven't been very successful so far. Yes, I think Misty is lying, but what if? Let's check it out.

Seems like NG was just skimming this subject on her show tonight but I would love to hear more from or about people who have failed the test and have been proven to be telling the truth. Does this happen often?

One day, polygraphs will be seen to be as unreliable as phrenology.

Cool video here, in which a skeptic of LD tests is hooked up and tested, using countermeasures to fool the test:

http://www.youtube.com/watch?v=GLL3wtgBiFA

"Polygraphy has little credibility among scientists.[21][22] Despite claims of 90-95% validity by polygraph advocates, critics maintain that rather than a "test", the method amounts to an inherently unstandardizable interrogation technique whose accuracy cannot be established. A 1997 survey of 421 psychologists estimated the test's average accuracy at about 61%, a little better than chance.[23] Critics also argue that even given high estimates of the polygraph's accuracy a significant number of subjects (e.g. 10% given a 90% accuracy) will appear to be lying, and would unfairly suffer the consequences of "failing" the polygraph."

http://en.wikipedia.org/wiki/Polygraph

Kimster said:

"Polygraphy has little credibility among scientists.[21][22] Despite claims of 90-95% validity by polygraph advocates, critics maintain that rather than a "test", the method amounts to an inherently unstandardizable interrogation technique whose accuracy cannot be established. A 1997 survey of 421 psychologists estimated the test's average accuracy at about 61%, a little better than chance.[23] Critics also argue that even given high estimates of the polygraph's accuracy a significant number of subjects (e.g. 10% given a 90% accuracy) will appear to be lying, and would unfairly suffer the consequences of "failing" the polygraph."

http://en.wikipedia.org/wiki/Polygraph

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Interesting! I think I read that Ted Bundy passed the LDT.

It is possible, I guess for Misty to be telling the truth, yet fail. I don't think that is the case.

I have found a few sites that talk about how unreliable polygraphs are, but they mostly seem to be trying to sell something. I'm sure they are not completely reliable, as they are not admissible in court. Still, I have found a few things that show that a LDT will likely show deceit when it is present.

http://www.howstuffworks.com/lie-detector.htm

People tell lies and deceive others for many reasons. Most often, lying is a defense mechanism used to avoid trouble with the law, bosses or authority figures. Sometimes, you can tell when someone's lying, but other times it may not be so easy. Polygraphs, commonly called "lie detectors," are instruments that monitor a person's physiological reactions. These instruments do not, as their nickname suggests, detect lies. They can only detect whether deceptive behavior is being displayed.

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Interesting video at the link above also, actually the whole thing is interesting.

I can't find anything other than bloggers stating that Bundy passed a poly, but I did find that Gary Ridgway passed it: http://en.wikipedia.org/wiki/Gary_Ridgway

The issue here is more about an INNOCENT person NOT passing it, however. I'm just not finding much information out there about such cases, only the one I cited regarding Melvin Foster.

Kimster said:

I can't find anything other than bloggers stating that Bundy passed a poly, but I did find that Gary Ridgway passed it: http://en.wikipedia.org/wiki/Gary_Ridgway

The issue here is more about an INNOCENT person NOT passing it, however. I'm just not finding much information out there about such cases, only the one I cited regarding Melvin Foster.

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I think that Gacy did, too, but I can't find any substantial link saying so.

Kimster said:

I can't find anything other than bloggers stating that Bundy passed a poly, but I did find that Gary Ridgway passed it: http://en.wikipedia.org/wiki/Gary_Ridgway

The issue here is more about an INNOCENT person NOT passing it, however. I'm just not finding much information out there about such cases, only the one I cited regarding Melvin Foster.

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Would a pathological liar pass a poly? I'm not sure, since I'm beginning to think Misty might be one.

Kimster said:

I can't find anything other than bloggers stating that Bundy passed a poly, but I did find that Gary Ridgway passed it: http://en.wikipedia.org/wiki/Gary_Ridgway

The issue here is more about an INNOCENT person NOT passing it, however. I'm just not finding much information out there about such cases, only the one I cited regarding Melvin Foster.

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Here's one story of an innocent person being held for 22 YEARS (!!!), who failed the polygraph, but then DNA exonerated him.

https://antipolygraph.org/blog/?p=138

Search DNA and polygraph on google. You'll get more results.

Maryann123 said:

Would a pathological liar pass a poly? I'm not sure, since I'm beginning to think Misty might be one.

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I do believe that a pathological liar could pass a poly.

I have no scientific data to back this up, but I do have a cousin who I grew up with, he is a pathological liar. There are lies that he has told since we were in kindergarten together, and still tells the same lies to this day. I know he's lying, he knows that I know he's lying, yet he states these lies as fact. I think he's told the story so much he believes it's the truth. I think if he took a LDT about the lie, he would pass.

Maryann123 said:

Would a pathological liar pass a poly? I'm not sure, since I'm beginning to think Misty might be one.

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I think so, and sociopaths as well!

Thing is, it's really hard to find any peer-reviewed, substantial scholarship about polygraphs, because most people in the scientific field give them no credence.

So being a scientist or behavioralist and writing a journal article about the fallacy of polygraphs would earn a big, "Yeah, we already knew that" from peers.

By the way, great thread, Kimster!

It's interesting when you search the internet and how much of it is how to beat the polygraph! Thank you for adding DNA to the search! That really helped! :highfive:

Maryann123 said:

Would a pathological liar pass a poly? I'm not sure, since I'm beginning to think Misty might be one.

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I think she is a pathological liar too. I'm quite sure LE asked Misty questions about Ron in one or more of her LDTs. Wouldn't they? I'm quite sure she stood by him then as she is standing behind him now and has been since the beginning.

What I'm getting at is: If she was asked questions about Ron and defended him as usual, showing deception (failing miserably) on the LDTs, wouldn't that mean that Misty was lying about Ron's involvement? Wouldn't that also mean that everything she said regarding Ron was a LIE? I guess it depends on the type of questions they asked but they had to ask her about Ron. They had to. Maybe that's why they both are sitting in jail with extremely high bonds.

LE had to question Misty about Ron, I mean why wouldn't they, he is Haleigh's father. Maybe that's why LE considered Misty "the KEY" to this investigation and not "a Suspect". She is covering for someone else and they know it.

If the examinee is nervous, will the polygraph test give a false positive?


Errors are usually referred to as either false positives or false negatives. A false positive occurs when a truthful examinee is reported as being deceptive; a false negative when a deceptive examinee is reported as truthful. Polygraph errors may be caused by the examiner's failure to properly prepare the examinee for the examination, or by a misreading of the physiological data on the polygraph charts.
Can the polygraph be wrong? "No," "However I was just called in by the spouse of a person who failed a pre-employment test. He failed when questioned on cocaine use. His spouse felt sure he had never used cocaine, so how could he fail?
One, he could have lied to her. Two, he might have something about the use of cocaine that bothered him. Perhaps someone used or purchased it in his presence, and it makes him feel uncomfortable. That would show up on the test.
What most people don't realize about a polygraph exam is that the examiner will go over the questions with the examinee several times, making sure there is no area of discomfort. It is vital to the integrity of the test that the examinee be honest about what is bothering them on any given issue before the test. In the case I just mentioned, if perhaps the issue was that someone had used cocaine in this man's presence, the examiner would have phrased the question, with that in mind. For instance, "Other than what you told me, have you ever used cocaine?" If the examinee was honest, the test will show it one way or the other.

more at the link:

http://www.truthorlie.com/falsepos.html

This was a good article with a lot of links:

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Lie detectors are likely lying themselves

The problem isn't that the machines don't record something&#8212;they do: heart rate, respiration, sweat-gland activity, and so on. But what the changes in those numbers mean is entirely up to interpretation.

Obviously there are two sides to this. On the one you have the American Polygraph Association (APA) and some law enforcement agencies. Neither of these are what you would call objective. The APA's existence depends on people accepting that lie detectors work, and as we've seen all too often, police and district attorneys are happy to have something that appears to provide evidence that can convict someone. (Lie detector tests are rarely allowed as evidence against someone in court &#8212; that should tell you something &#8212; but "failing" a test can sway public opinion, and jury members aren't hermits.)

On the other side you have, well, dozens of groups and organizations with names like AntiPolygraph.org and StopPolygraph.com. If you're like me, you might at first blush think these are fringe groups with their own (hidden) agenda, and that they aren't about to provide unbiased information. After all, there's always a conspiracy theorist to be found.

Except that also on the anti-polygraph side I found the American Medical Association, the American Psychological Association, and 60 Minutes. They all found essentially the same thing: Lie detectors show what the examiners want them to show.

In 1986, 60 Minutes demonstrated this rather dramatically. Using Popular Photography magazine as a front, the producers hired several polygraphers to help find someone who had, they were told, stolen hundreds of dollars of photographic equipment. (No such theft had taken place.) Each examiner was told that a different one of the 'suspects' was probably the guilty party.

Lo and behold, each polygrapher fingered the suspect they were told ahead of time was probably guilty. Oops.

http://www.usatoday.com/tech/columnist/andrewkantor/2004-04-08-kantor_x.htm

polygraph ("lie detector")

The reason the polygraph is not a lie detector is that what it measures--changes in heartbeat, blood pressure, and respiration--can be caused by many things. Nervousness, anger, sadness, embarrassment, and fear can all be causal factors in altering one's heart rate, blood pressure, or respiration rate. Having to go to the bathroom can also be causative. There are also a number of medical conditions such as colds, headaches, constipation, or neurological and muscular problems which can cause the physiological changes measured by the polygraph. The claim that an expert can tell when the changes are due to a lie and when they are due to other factors has never been proven. Even if the device measures nervousness, one cannot be sure that the cause of the nervousness is fear of being caught in a lie. Some people may fear that the machine will indicate they are lying when they are telling the truth and that they will be falsely accused of lying. Furthermore, even the most ardent advocate of the polygraph must admit that liars can sometimes pass their tests. One need only remember the spy Aldrich Ames, who passed the polygraph test several times while with the CIA.

http://www.skepdic.com/polygrap.html

I wonder how being desperate to get out of jail would affect the test and thinking that the police are being impressed that she's telling the truth just by being willing to take one.