Polygraph Testing

[Atothetheist]

My girlfriend and I love to watch reality TV shows, and one of the shows has couples or exes hooked up to a polygraph test (I’m sure you’ve seen clips of it on FB). I got interested in the fact that my girlfriend and the general public as well as the contestants of the show seem to have this belief that polygraph testing I is super accurate. I personally never knew how accurate Polygraphs were, but I seem to recall that they aren’t really used as evidence in court. My girlfriend stated that polygraph’s have an over 90 percent accuracy rate. 

Looking it up, however, there seems to be a whole lot of uncertainty when it comes to polygraph testing. And the public perception seems to give it more credit than the scientific community. Is polygraph testing a pseudoscience?

[Gawdzilla Sama]

I was assigned to lie to a polygrapher once. He believed everything I said. I simply believed what I said.

[epronovost]

Polygraph cannot detect lies. They can only detect symptoms of nervosity. People tend to be nervous when they lie. Good liars can fool the polygraph. Nervous people can screw with it. Sociopath consistently beat it. It's a big pile of pseudoscience.

[Szuchow]

Here is what APA think*:

[...] "The accuracy (i.e., validity) of polygraph testing has long been controversial. An underlying problem is theoretical: There is no evidence that any pattern of physiological reactions is unique to deception. An honest person may be nervous when answering truthfully and a dishonest person may be non-anxious. Also, there are few good studies that validate the ability of polygraph procedures to detect deception. As Dr. Saxe and Israeli psychologist Gershon Ben-Shahar (1999) note, "it may, in fact, be impossible to conduct a proper validity study." In real-world situations, it's very difficult to know what the truth is.[...]


*
https://www.apa.org/research/action/polygraph

[Atothetheist]

Polygraph cannot detect lies. They can only detect symptoms of nervosity. People tend to be nervous when they lie. Good liars can fool the polygraph. Nervous people can screw with it. Sociopath consistently beat it. It's a big pile of pseudoscience.

In which case, are these reality shows, no matter how entertaining, harmful to the general public because of the promotion of Polygraph tests? How many couples think that they could get truthful answers because of shows like this? What are your thoughts?

[Dom]

Polygraph cannot detect lies. They can only detect symptoms of nervosity. People tend to be nervous when they lie. Good liars can fool the polygraph. Nervous people can screw with it. Sociopath consistently beat it. It's a big pile of pseudoscience.

In which case, are these reality shows, no matter how entertaining, harmful to the general public because of the promotion of Polygraph tests? How many couples think that they could get truthful answers because of shows like this? What are your thoughts?

Some of these testers ask a ton of unrelated questions first to determine what sort of reactions the subject has to normal questions. It's an attempt to weed some errors out, but you have had subjects putting a pointy object in their shoe for example, and slight movement will trigger an agitated response. And so forth. So the subject would have to have submitted to a thorough search of their person first. Some police use them I hear, and they do try to eliminate all the odd reactions they can. What they cannot eliminate is psychopaths, pathological liars and so forth. Or anxious people, etc.


So, even with utmost care the readings can still be totally wrong. 

I don't know how popular such shows are. Anything that has people believing in things outside of reality can be harmful to some. Then again, there are millions of people reading horoscopes and it seems harmless, people have been reading those for a very long time. Perhaps a warning should be stated, just like tobacco company have to warn their customers about their product.

[mordant]

I think its an appealing idea that lies can be "detected" empirically, and given that polygraphs have been used many times as plot devices in crime dramas throughout the years, and portrayed as accurate or revealing, sure the public tends to think more highly of them than they ought.

I am not a lawyer but here's a link about the murky status of admissibility of polygraph evidence:

https://www.justice.gov/jm/criminal-reso...tion-trial

The takeaway for me from that is that people are suspicious of their use as evidence and the only reason they ever are considered is a concern over a defendant's ability to use them in defense (however questionable) of their veracity. I suppose that in practice, they might be used along with other evidence in such a way that they can on occasion bring the preponderance of evidence to a tipping-point one way or the other.

[Gawdzilla Sama]

Problem is, there's no science behind it.

[Dānu]

A related technology is 'brain fingerprinting'. Apparently the jury is still out on that one.

In 1999, a woodcutter named James B. Grinder confessed to a 15-year-old murder, the death of a 25-year-old woman named Julie Helton. A short time later, he recanted, contradicting himself over and over. His blood had been taken and compared against the crime scene samples — but with such an old crime, local police were worried the case might fall apart, so the sheriff called in a doctor he had seen on the news. The doctor's name was Lawrence Farwell, and he was promoting a next-generation tool called brain fingerprinting. It was an advanced lie detector that claimed to look into a suspect's brain to see if they were familiar with the details of the crime. This was the first time the technique had been used in an active criminal case, although Farwell had tested the technique with scientists at the FBI. So far, he said, the accuracy rate was 100 percent.

The local police were thrilled to try it out, so Farwell set up his computer at the prison where Grinder was being held, along with the bundle of wires and electrodes used to take EEG readings of brain activity. Grinder sat in front of a screen in his orange jumpsuit, with a blue strap over his forehead to secure the device. Behind him, Farwell asked questions and monitored the results on a screen, grilling the convict about specific details of his crime. By the time the test was over, Farwell was convinced. Faced with overwhelming evidence, Grinder pled guilty and was sentenced to life without parole. "There is no question that J. B. Grinder raped and murdered Julie Helton," Farwell told a local paper after the plea. "The significant details of the crime are stored in his brain."

---

Even for those who believe in the science behind the P300, there are real questions about how it will stand up in an actual investigation. A recent study compared P300 with the skin conductance response, used in the common polygraph lie detector, and came away with mixed results. When innocent participants were included, the P300 far outpaced the traditional polygraph, resulting in far fewer false-positives. But when the participants had to work through an actual crime scenario, stealing a purse and then being confronted with details, the P300 was often less reliable than the polygraph. The questioners were forced to guess at what actually happened, introducing new uncertainty and driving up error rates. Many guilty suspects ended up passing the test simply because they hadn't paid attention to the objects in the test.

Is 'brain fingerprinting' a breakthrough or a sham?

[SYZ]

Polygraphs utilise the electrical resistance of skin—which changes as a person perspires—blood pressure, heart and breathing rates.
Which is true, but meaningless in legal terms.  So does a flu vaccination, a clap of thunder, a dentist's drill, or an orgasm(!).
No lying necessary LOL.

This is an Aussie scammer—Steve van Aperen—who lists so much bullshit on his site it's truly laughable:

https://polygraph.com.au/

They say "We have been used by 60 Minutes, Sunday Night, A Current Affair, Today Tonight
and various media outlets throughout Australia and New Zealand to provide lie detection services,
truth verification and polygraph testing on numerous high profile cases", which they then list.  
Not one of these "cases" which are listed had any legal ramifications or social value.  They were
all sensationalist media fodder fed to a voyeuristic public.

He was also profiled in the media a couple of years ago under the headline "Steve van Aperen is
the human lie detector who catches serial killers".  Which he has not done.  Even once.

[Minimalist]

My girlfriend and I love to watch reality TV shows, and one of the shows has couples or exes hooked up to a polygraph test (I’m sure you’ve seen clips of it on FB). I got interested in the fact that my girlfriend and the general public as well as the contestants of the show seem to have this belief that polygraph testing I is super accurate. I personally never knew how accurate Polygraphs were, but I seem to recall that they aren’t really used as evidence in court. My girlfriend stated that polygraph’s have an over 90 percent accuracy rate. 

Looking it up, however, there seems to be a whole lot of uncertainty when it comes to polygraph testing. And the public perception seems to give it more credit than the scientific community. Is polygraph testing a pseudoscience?

Polygraphs are still not accepted as evidence in court.

Worse, ballistics, fingerprints, and fiber analysis has been shown to be spotty as well.

https://thinkprogress.org/forensic-evide...a72ef4581/

If you were to judge the criminal justice system based on TV shows like Law and Order or CSI, you might think forensic evidence is conclusive proof of a person’s guilt. Reality is much messier. DNA is widely considered an accurate indicator of a defendant’s involvement in a crime, but prosecutors also turn to less trustworthy evidence, including hair microscopy, bite mark comparisons, firearm tool mark analysis and shoe print comparisons. There is little research to suggest that forensic matches are scientific and infallible.

[Fireball]

The gov uses polygraphs to screen people in sensitive positions. Over-reactors like me have a bitch of a time passing, and others, who I know are pathological liars and common thieves waltz right through.

[SYZ]

The gov uses polygraphs to screen people in sensitive positions. Over-reactors like me have a bitch of a time passing, and others, who I know are pathological liars and common thieves waltz right through.

Fuck me!  I couldn't believe this when I read it, but it's true.

"Agencies may require polygraph exams for applicants to positions with certain
levels of security clearance, or to renew security clearances. Most agencies who
administer them are within the Defense Department and Intelligence Community".

To tell the truth: What current and hopeful federal employees should know about polygraphs

Surely this is an encroachment upon one's civil liberties?  Or illegal discrimination? Or just simple bastardry?

[Minimalist]

Those who refuse to take the exam may not be able to proceed with the application process.

There is no civil liberties issue.  One is not forced to take the test.  Of course if you don't they will not hire you.  But there is no constitutional right to a job.  Go work somewhere else that does not fixate on polygraphs.

[Aractus]

Polygraph cannot detect lies. They can only detect symptoms of nervosity. People tend to be nervous when they lie. Good liars can fool the polygraph. Nervous people can screw with it. Sociopath consistently beat it. It's a big pile of pseudoscience.

Or more accurately, symptoms associated with lying.

Polygraph testing hawks back to the time when law enforcement still believed that they could discern the truth and extract it in virtually all circumstances - a long since discredited theory. That was a time that denied the very existence of false confessions for example.

[TheGentlemanBastard]

Polygraphs are still not accepted as evidence in court.

This is a common misconception. Many jurisdictions allow polygraphs as evidence, but the majority of those require an agreement between the prosecuting and defending attorneys that the results be admissible before the test is taken.

[Chas]

The "results" of a polygraph are an interpretation by the examiner. It is opinion, not fact. Belief in them is woo.

[Minimalist]

Polygraphs are still not accepted as evidence in court.

This is a common misconception. Many jurisdictions allow polygraphs as evidence, but the majority of those require an agreement between the prosecuting and defending attorneys that the results be admissible before the test is taken.

Why would either side introduce a piece of evidence which does not support their side of the argument?

[Tres Leches]

Back in the old days (the 1970s) I remember a babysitter telling me she had to take a polygraph test - it was called a lie detector test back then - while applying for a job as a cashier in a supermarket. This was before this type of pre-employment testing was outlawed. Imagine that - going to apply for some dead-end minimum wage job and being wired up for a lie detector test.

I'm not big believer in polygraph testing, especially when using this as the only factor when making a decision on a set of circumstances. Human behavior is too variable to be put inside a neat box with tidy results.

-Teresa

[Bucky Ball]

I am learning to practice phrenology.
I don' need no stinkin' lie detector.
I can tell ALL about people by the bumps.
The bumps on their head.
https://en.wikipedia.org/wiki/Phrenology

[Dānu]

Back in the old days (the 1970s) I remember a babysitter telling me she had to take a polygraph test - it was called a lie detector test back then - while applying for a job as a cashier in a supermarket. This was before this type of pre-employment testing was outlawed. Imagine that - going to apply for some dead-end minimum wage job and being wired up for a lie detector test.

I'm not big believer in polygraph testing, especially when using this as the only factor when making a decision on a set of circumstances. Human behavior is too variable to be put inside a neat box with tidy results.

-Teresa

The worst part is that companies would do this kind of testing and then not share the result with the applicant. They'd simply decline to consider hiring the applicant, and you had no idea if it was because of the test or something else.

[TheGentlemanBastard]

Polygraphs are still not accepted as evidence in court.

This is a common misconception. Many jurisdictions allow polygraphs as evidence, but the majority of those require an agreement between the prosecuting and defending attorneys that the results be admissible before the test is taken.

Why would either side introduce a piece of evidence which does not support their side of the argument?

Got me, but that's the law in some jurisdictions. I was offered a polygraph when I got sued for someone else's illegal downloading of porn, using my hacked home network, so I researched it. My attorney advised me not to take the test as their attorney wanted it marked admissible in court. Had I passed, it would have ended the case, had I failed, it would have sunk me and considering the unreliability of the testing, I followed her advise. She beat their bullshit case and provided new precedent for future piracy cases too.

[mordant]

Why would either side introduce a piece of evidence which does not support their side of the argument?

My understanding is that if a defendant knows they are telling the truth, and believes a polygraph test will "prove" that they are, they might advocate for taking one. If the prosecution also believes in the polygraph and thinks the test will "prove" them to be liars, they might go along with it. Besides, they can always ask for more tests from different operators until they get the result they want.

The other thing I'm given to understand that none of this comes into play to begin with unless there's a paucity of hard evidence. If there are 20 people who witnessed the butler murdering the heiress with a candlestick in the library, plus blood spatter and forensic evidence including DNA and fingerprints, then a polygraph test makes little sense to anyone.

[Minimalist]

For the hell of it I put < jurisdictions where polygraphs are admissable> into google and got this.... which did not answer the question but provided some insight.

https://www.hg.org/legal-articles/is-a-p...ence-31737

In the rare instance that both parties agree that the results of a polygraph exam should be admissible for some reason, the court could allow it as evidence. Polygraphs are also commonly used as part of the screening process for certain types of jobs, such as law enforcement and some high level security positions. Nevertheless, for purposes of court procedures, absent a stipulation of the parties, the results of a lie detector test are likely never admissible.

That probably explains how so many cops are so good at getting on the witness stand and lying their asses off.  It was a job requirement!

[SYZ]

The admissibility of evidence derived from a polygraph machine is generally not considered valid by Australian courts.

In R v. Murray, Sinclair DCJ in the District Court of New South Wales, set out the reasons as to why polygraph evidence
was inadmissible after the accused sought to call on the operator of a polygraph machine to validate that his denials to
the charges were correct after taking a lie detector test.

His Honour stated that the polygraph operator’s testimony was not valid because:

•  his expression of an opinion as to the facts of the issue, should be within the province of the jury to determine on the
facts, presented to them by witnesses who perceived them by the exercise of their physical senses,

•  the witness was not a qualified expert, but rather an operator and assessor of a polygraph machine,

•  devoid of any scientific basis, the evidence of the polygraph operator was considered as hearsay, with no probative value.

To further illustrate the point, we can look to s 6(1) of the Lie Detectors Act of New South Wales which states that any
evidence adduced from a polygraph machine will be considered as inadmissible by the courts.

—FindLaw Australia