Polygraph tests

[NikolaeVarius]

Does this happen to be Indiana College?

 

[iCyborg]

This belief that polygraphs are "worse than useless" seems very common here too. Sadly since the evidence suggests otherwise. No, they aren't 100% correct, or even 98% correct, and one can be trained to defeat it, but it's a proven fact that they are heck of a better than the alternative, which is humans. And I can definitely see why they *could* be useful with students who aren't trained and prepared to lie.

The author is awell known physicist R.A. Muller:
http://muller.lbl.gov/TRessays/19-LieDetectors.html

Some excerpts:

I can summarize these results in an oversimplified but helpful way: the polygraph procedure has an accuracy between 80 and 95 percent. Let’s call it 85 percent.
...
Ironically, scientific tests show that the average person’s probability of catching a lie in this way is only “slightly better than chance,” according to Ekman.
...
Polygraphy is not allowed in courts because 85 percent accuracy is not good enough. Instead courts use a system that is demonstrably worse—which could be a big part of the reason why so many convictions are now being overturned by DNA evidence. Where is the wisdom in that?

 

[ManBearPig]

Does this happen to be Indiana College?

yeah, IU. i feel really awful for the girl and her family (article).

 

[Howard]

They're just using it as a scare tactic since kids nowadays are too stupid to know anything about polygraphs.

http://www.youtube.com/watch?v=rN7pkFNEg5c

EDIT: If you're not familiar with these scenes, watch the whole thing.

 

[Mike Gayner]

This belief that polygraphs are "worse than useless" seems very common here too. Sadly since the evidence suggests otherwise. No, they aren't 100% correct, or even 98% correct, and one can be trained to defeat it, but it's a proven fact that they are heck of a better than the alternative, which is humans. And I can definitely see why they *could* be useful with students who aren't trained and prepared to lie.

The author is awell known physicist R.A. Muller:
http://muller.lbl.gov/TRessays/19-LieDetectors.html

Some excerpts:

I can summarize these results in an oversimplified but helpful way: the polygraph procedure has an accuracy between 80 and 95 percent. Let’s call it 85 percent.
...
Ironically, scientific tests show that the average person’s probability of catching a lie in this way is only “slightly better than chance,” according to Ekman.
...
Polygraphy is not allowed in courts because 85 percent accuracy is not good enough. Instead courts use a system that is demonstrably worse—which could be a big part of the reason why so many convictions are now being overturned by DNA evidence. Where is the wisdom in that?

The stupidity of this post boggles the mind. The alternative to a polygraph isn't a human trying to detect a lie - the alternative is actual evidence, of which a polygraph provides NONE. Polygraphs are complete and utter nonsense. See excerpts from this review of the literature:

Overall, the evidence is scanty and scientifically weak.
...
Moreover, most polygraph testing procedures allow for uncontrolled variation in test administration (e.g., creation of the emotional climate, selecting questions) that can be expected to result in variations in accuracy and that limit the level of accuracy that can be consistently achieved.
...
The theoretical rationale for the polygraph is quite weak, especially in terms of differential fear, arousal, or other emotional states that are triggered in response to relevant or comparison questions. We have not found any serious effort at construct validation of polygraph testing.
...
Research on the polygraph has not progressed over time in the manner of a typical scientific field. It has not accumulated knowledge or strengthened its scientific underpinnings in any significant manner.
...
Polygraph examinations may have utility to the extent that they can elicit admissions and confessions, deter undesired activity, and instill public confidence. However, such utility is separate from polygraph validity.

 

[iCyborg]

The stupidity of this post boggles the mind. The alternative to a polygraph isn't a human trying to detect a lie - the alternative is actual evidence, of which a polygraph provides NONE. Polygraphs are complete and utter nonsense. See excerpts from this review of the literature:

I try not to bother responding to someone who can't disagree with a normal post without insulting, but I'll make an exception:
I've mostly quoted Muller who based his post on provided references. If professors from UCLA Berkeley are too stupid for you, then perhaps I'm in good company...

That article of yours concentrates on "validity for security uses, especially those involving the screening of substantial numbers of government employees".

So why can't police find that girl then? And why can't they solve all the crimes? I mean, all they have to do is use the alternative: actual evidence. Apparently, it's always readily available...

Duh, of course you will use actual evidence when you have it. But when you need clues and pointers to even start a search, perhaps using methods like this can give you something. Of course you shouldn't put someone in jail for failing the test, but forming suspicions and then trying to confirm them is better than blindly searching around armed with hunches.

 

[Locut0s]

I try not to bother responding to someone who can't disagree with a normal post without insulting, but I'll make an exception:
I've mostly quoted Muller who based his post on provided references. If professors from UCLA Berkeley are too stupid for you, then perhaps I'm in good company...

That article of yours concentrates on "validity for security uses, especially those involving the screening of substantial numbers of government employees".

So why can't police find that girl then? And why can't they solve all the crimes? I mean, all they have to do is use the alternative: actual evidence. Apparently, it's always readily available...

Duh, of course you will use actual evidence when you have it. But when you need clues and pointers to even start a search, perhaps using methods like this can give you something. Of course you shouldn't put someone in jail for failing the test, but forming suspicions and then trying to confirm them is better than blindly searching around armed with hunches.

Then they should also listen to fortune tellers and voodoo priests because hay they might point out new leads too.

 

[wirednuts]

if theyre just being used to weed out the weirdos, then why not take it? act like nothings wrong and take it, and even if you fail who cares? its useless anyway?

 

[Locut0s]

if theyre just being used to weed out the weirdos, then why not take it? act like nothings wrong and take it, and even if you fail who cares? its useless anyway?

Then what is the point of it. How does it "weed out" the "weirdos"?

 

[iCyborg]

Then they should also listen to fortune tellers and voodoo priests because hay they might point out new leads too.

Do you have any scientific studies to show that they have a demonstrated 80-95% efficiency in telling liers or providing useful clues? If not, then it's not the same thing...

 

[bignateyk]

Are they forcing you to take it? I sure as hell wouldn't. We are forced to take them for our job and I've failed before (You just end up having to retake it to pass). They aren't accurate at all. I wouldn't want myself to end up a suspect in a murder because of an all-to-common false positive on a poly.

 

[rasczak]

http://www.youtube.com/watch?v=rN7pkFNEg5c

EDIT: If you're not familiar with these scenes, watch the whole thing.

lol

 

[ichy]

The science behind polygraphs is a joke, however people talk when they're hooked up to them. The reason that the gov't uses them for security clearances is that people will tell the truth about stuff they'd otherwise lie about even if they know that the poly's accuracy is pretty mediocre. As for their use in a criminal investigation, anyone who agrees to get hooked up to a police polygraph is a damned fool.

 

[BladeVenom]

Then they should also listen to fortune tellers and voodoo priests because hay they might point out new leads too.

If you ever listen to lie detector operators, they do sound a lot like fortune tellers. They use some of the same tricks and excuses.

 

[NikolaeVarius]

yeah, IU. i feel really awful for the girl and her family (article).

Ah well, she went to my high school. My facebook page has about 50 freaking separate threads about this.

 

[BeauJangles]

Do you have any scientific studies to show that they have a demonstrated 80-95% efficiency in telling liers or providing useful clues? If not, then it's not the same thing...

80-95%? What about nearly every single espionage case in this country where the suspect was polygraphed repeated and passed with flying colors?

So why can't police find that girl then? And why can't they solve all the crimes? I mean, all they have to do is use the alternative: actual evidence. Apparently, it's always readily available...

This is a terrible way to think about a polygraph. The point being made is that there are methods (actual investigative techniques) that return far more accurate results than polygraphs do.

 

[ManBearPig]

Ah well, she went to my high school. My facebook page has about 50 freaking separate threads about this.

It's so fucked up...I live maybe a minute driving away from there, I go to the gym under her apartment building. I've been to the same bar hundreds of times. Every student has probably been in a similar situation as her when she got abducted so it's really startling.

 

[amdhunter]

lol. I could beat a poly test easily. For example - Ask me if I am Black. Do you honestly think one of those machines won't believe me?

 

[NikolaeVarius]

It's so fucked up...I live maybe a minute driving away from there, I go to the gym under her apartments. I've been to the same bar hundreds of times. Every student has probably been in a similar situation as her when she got abducted so it's really startling.

I won't say I ever liked her, in fact I hated the shit out of her social group. All of them idiots. The circumstances that she put herself in though, was not exactly ideal.

5am, coming back from a bar (probably drunk considering it was supposed to be a party), barefoot, alone, and a friend that doesn't remember the last 15 minutes that he was with her. I mean, comon, can you get that much more irresponsible?

Though, I still do hope they find her.

 

[ShawnD1]

Do you have any scientific studies to show that they have a demonstrated 80-95% efficiency in telling liers or providing useful clues? If not, then it's not the same thing...

It only works like that in people who are very emotional and feel guilt. It doesn't work in anyone else. Serial killers pass polygrip tests very easily because their pulse doesn't go up when they lie or when police try to shock them. You've probably met people who are like that - they can lie right to your face without missing a beat. A car salesman would probably pass a polygraph since they seem to be experts when it comes to lying while remaining calm and keeping a straight face.

What about nearly every single espionage case in this country where the suspect was polygraphed repeated and passed with flying colors?

The machine doesn't work on people who are compulsive liars, people who know how to trick the machine (clench your ass when telling the truth), and people who are not afraid of the machine.

 

[dabuddha]

I would absolutely be as helpful as possible, and seeing as how the test would not assist them in any way, I would decline and save them the time.

So they waste a ton of time on suspecting you.

 

[ShawnD1]

So they waste a ton of time on suspecting you.

You mean it's heaty to not give straight answers to the police? I suppose that would make sense. The police gave me a really hard time when I refused to tell them my name and didn't tell them where I live or where I'm from. Those dipshits acted like I was trying to hide something.

 

[BeauJangles]

The machine doesn't work on people who are compulsive liars, people who know how to trick the machine (clench your ass when telling the truth), and people who are not afraid of the machine.

Yeah, there are definitely countermeasures out there, but polygraphs have gotten smarter about the physical ones. I think they use something in the chair to detect any "strange ass movement."

As for the spies, I'm continually amazed that when you read their stories they'll talk about when they found out they were going to be polygraphed. Often they would relay that information back to their handler and ask what they should do. The usual was response wasn't a list of countermeasures, but simply "get a good night's sleep and don't worry about it."

My problem with polygraphs is that I think they're harmful to national security. Not only do they routinely disqualify people on the basis of false positives, but they also lead investigators astray. They are a shortcut for real counterintelligence work and I believe that they turn up significantly less than a good thorough background investigation.

 

[brandonb]

I have watched enough "First 48" to know how this works:

Innocent until proven guilty. Typically how things work in court.

Guilty until proven innocent. Thats what the polygraph is doing... Proving to the detectives that someone innocent so the detectives can move onto someone else and stop wasting time "grilling" someone who is innocent.

 

[ShawnD1]

My problem with polygraphs is that I think they're harmful to national security. Not only do they routinely disqualify people on the basis of false positives, but they also lead investigators astray. They are a shortcut for real counterintelligence work and I believe that they turn up significantly less than a good thorough background investigation.

This is the biggest problem. If the guilty person you're looking for is a heat bag, a polygraph test is a great way to find a list of suspects. The people who get really nervous - those are your suspects.
When it's the other way around and the person you're looking for is cool and can beat a polygraph, the polygraph completely throws off the investigation. The guy who did it was dismissed because he passed the test, so you end up wasting time looking at the heatbags who were sweating bullets in the test.