Beating a Polygraph by mentally rephrasing the question???

Factual Questions
1

Dopers,

Over here in the UK we have a series called ‘Meet My Folks’ where a group of suitors are interviewed by the parents before being whittled down to the last two. The final test is a polygraph test where the two remaining boys are asked questions such as ‘Will you try and sleep with my daughter’. The gentleman administering the test gives the thumbs up/down to indicate to the parent(s) whether the subject is lying (or not).

This brought me to wondering (it doesn’t take much!). When a polygraph is administered, what is to prevent you answering a question you asked yourself mentally. In this case for instance, rephrasing the question mentally and asking yourself ‘Would I turn down the opportunity to sleep with your daughter if I think I have a hope in hell of actually succeeding?’. The answer you give to this question is ‘No’ but you are not answering the question the parents asked.

On a more obvious level, what’s to stop you asking yourself the question ‘Am I male/female’ and answering Yes/No depending on the answer that you think you should be giving to the examiner (‘Did you steal the car’ etc …)

I don’t mean to insinuate that all dopers are skilled liars :smiley: but I would like to know how a polygraph can tell if you are answering the question asked by the examiner or one you posed to yourself immediately after the question was asked.

BTW I know they are unreliable and their use is being pruned back to a certain degree but they are still used.

2

I don’t think it would work. Polygraph tests work by detecting stress that goes along with lieing, it seems to me you would then get a resoponce because they know intelectually they are lieing.
Oh and we had that show here (States) but it got cancelled

3

Mmmmm … I can understand why it was cancelled - its not great TV !!

This is exactly my problem *Tallayan *. You’re not lying.

The stress would only really be from wondering wether it would work.

If you guys all come up with a really good, rational explanation of why my idea is brilliant :dubious: then should I ever have the misfortune to find myself in the position of taking a polygraph I could take it knowing that using this trick will defeat it and as a result … no stress :smiley:

4

I had to take a polygraph for a job once (I was in high school going for a job as a busboy at T.G.I. Fridays…go figure). One of the questions they asked me was, “Do you have any hidden reasons for wanting this job.” Huh? I thought about it some and couldn’t figure out what they were asking so I said no. After the test I went up to the tester and asked him what, exactly, that question meant. He said it was a good thing I asked him that as it was the only question I failed (FTR he said the question was to determine if I was a ‘spy’ for another company or things like that).

Anyway, it occured to me that just thinking about the question overly much produced a result that looked like a lie to a polygraph. I suppose the idea is that the truth should just pop out while a lie takes longer to formulate.

With this in mind I tested my theory the next time I took a polygraph (this time for a job at the Board of Trade in Chicago). When the polygraph starts the tester asks some simple, baseline questions. What is your name? Do you ive at XXX in Chicago? Stuff like that. From these simple, obviously truthful answers, they can set the base for the answers to follow. When he asked, “Is your name Whack-a-Mole?” I deliberately paused and thought to myself, “Is my name Whack-a-Mole? I suppose it could be something else but I guess Whack-a-Mole is safe for now.” After that I answered, “Yes.” The tester then asked me my name again and I did it again. He tried once more and I did it a third time. He told me to take a minute and relax then started up once more a minute or two later. Since I had nothing to hide and was satisified by my personal little test I stopped playing around (and passed the test).

The upshot is it would seem the mere act of trying to reformulate the question in your mind will probably show as a blip on the polygraph and suggest you are lying.

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Another method would be just not to listen to the question, and just say yes/no alternately, assuming it warranted a yes no answer.

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Read up on the polygraph:

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And this is why polygraph sessions aren’t admissible as evidence in court. Lie detection is an art, not a science.

FTR, they say that if you’re the type of person who can lie without feeling guilty about it, then you can beat any polygraph.

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I can say that pretty much every trick you’ve ever seen in the movies will work.

I spent several years working at a small company that sold and repaired medical sensors and software packages for them.

As has already been said, these things are good at detecting stress. That is all.
Clench and unlcench your buttocks. Alternately think about Salma Hayek, Shakira, and Tyra Banks licking whipped cream off your body-and cockroaches,centipedes, and maggots crawling on your naked body. Bite your tongue. Spend a lot of time before the test convincing yourself how unreliable the machine is and that you have nothing to worry about.
As has also been mentioned, the reverse is true. Worrying about a particular question will cause you to fail. A cop I knew, let’s call him Rob, failed the polygraph when transfering departments. One of his friends had stupidly mentioned that he had become so nervous over a drug use question, he had failed the test despite never using drugs. Having heard this story, Rob began worrying that the same thing would happen to him. It did. He became so nervous over that question, the polygraph readings made it seem that he was lying. I knew Rob for several years. He had his failings. But, he was a great cop. One of his prize possessions was a photo of him standing beside a 6 foot tall cannibis plant. He’s holding a branch in one hand and his badge in the other. Busts like that one were the only time he was ever around drugs. He made it clear that to his friends and family that if they used drugs, they’d be arrested the same as anybody else. Yet, the ‘lie detector’ said Rob had lied about using drugs.

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Damn! Where did my reply go?!?!

I said:

I believe the machine may just read your initial OMG! I better reformulate this one! - Bang - Busted!

You may be cool (i.e. pass) after you have re-asked yourself the question, but the initial OMG! has already tagged you.

Now, if you think way to hard about each question asked of you, the initial stress of thought may confuse the machine.

IANAPT (polygraph tech) but I do have a degree in Psychology:)

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DocCathode:
Rob is a dick - and this in a truthful answer, not IMHO!

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IANAL (I am not a liar*) and I’ve never given or taken one, but I believe I know a bit about polygraph tests.

The machine itself is little more than a glorified “Machine that goes PING!” ie heartrate monitor etc. Some of the things which could be usefully measured are, of course, the heart rate, but also respiration, galvanic skin response, and various other stuff. These are bodily functions not normally under conscious control but still controlled by the mind, and hence indicators of the mind’s activity.

Imagine a guilty bad guy hooked up, and a cop asking questions. The cop looks at the bad guy and says “I know you did it, now just confess!”

Unless that bad guy has amazing nerves, at SOME point in there a tiny part in the back of his mind will panic. “OH SHIT! He KNOWS! We’re in trouble now!” This will send adrenaline into the body, etc etc, the classic fight or flight response… heart rate, respiration, everything, will change…

…but just for a second. Then the rational part of his mind will say “Shut up, you! They don’t know nothin’! We just sit here all quiet like and they gotta let us go eventually!” He will calm down, heart rate etc will drop back to normal. If he’s good at it, this will take only a fraction of a second, happening far too quickly to be seen with the naked eye. The cop’s got no idea that, for just a second, the guy was really worried.

But the machine does. It picked up that “BLIP”… if you look at the printout, there are big ol’ squiggly marks. The guy running the polygraph makes a note by them… at such and such moment, after this question was asked, the suspect’s heart rate and respiration jumped to nearly double their normal rate… for just a second.

This is how they know you’re lying. But of course, it’s not perfect. Maybe, just maybe, when they asked him that question… I dunno, a bee flew down his pants. I know that would make MY heart rate jump!

So they ask again. “We said we know you did it, now you’re lying to my face?” BLIP! it goes again. “We have the car.” BLIP “We have the gun.” no blip “We have your friend in the next cell telling us everything that happened.” BLIP

Ahh… now we’ve got something. Blips at he did it, blips at the car, blips at the accomplice… no blip on the gun. We now know, or think we do, what he’s lying about.

But can anybody say for 100% certain which is the lie and which the truth? No. It’s, as stated earlier, an art, even though the methods are science.

So why did they think you were lying about having ‘ulterior motives for applying’? The pause… the various things that fluttered briefly through your head gave readings. These readings may or may not have indicated a lie. Why did they ask you your own name three or four times? Because, while you were thinking about it, the readings went wacko.

What a polygraph should more accurately be named, I think, is a truth detector. When you’re telling the truth, you’re totally relaxed… you don’t have to stop and think about what you’re going to say. That moment of thinking is what the machine detects, as various thoughts run through your subconscious and affect your body. If you don’t think about it, then there are no responses to detect… or perhaps different ones. I dunno. q;}

So to answer the OP, they can’t possibly know what question you are answering. All they can hope to do is gauge your reactions to what you are asked… and no matter how good a liar you are, you ARE going to react to them. That’s why polygraphs work at all.

Extreme cases of insanity (sociopathy etc) are an entirely different matter.

  • may or may not be true
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And a lot of people BLIP when being entirely truthful, but reacting poorly to the stress of taking the test. Polygraphs are basically sophisticated BS.

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Yep.

Think about how a (insert your favorite cause here) would reach to a question about their cause (say abortion - there are usually high emotions about this subject).

Regardless of what side of the debate one may be on, the topic its self will generate the “blip”

14

or

react to a question

15

Whack-a-mole and ianlyte, what would be your respective opinions to the results of a test where the subject simply blurted out an arbitrary answer as soon as the question was asked, like istara has mentioned.

You would not be able to think about the question for fear of causing a blip. So you will not know how you actually answered the question until a moment later.

That’s an interesting quandary, because it is the same as the riddle about the two people standing side by side, White and Red. One always lies and the other always tells the truth. How do you figure out which one is the liar and which one is the truth teller?

My opinion is that the test would be repeatedly thrown out because it will be deemed inconclusive.

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…Something I forgot to ask in my last post. For anyone who is knowledgeable about how the whole Polygraph Test functions, what effects would imbibing something before taking a test have on the test. A couple examples:

hot coffee
cold water
marijuana
alcohol

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In one of the Stainless Steel Rat stories, the Rat is given a polygraph. He worries about “OH SHIT! He KNOWS! We’re in trouble now!” during the test questions (is this your name, is this where you live…) and then when they ask the big one “DID YOU DO IT?” which he knows is coming, he relaxes and says “no.” Pass.

I also read a study where they had experienced fiction writers take a polygraph as themselves and then as one of their characters. When “in character” the writers were able to give completely different answers without getting the “DING”–they have the habit of thinking of themselves as someone different. My guess is that experienced role-playing folk could do the same.

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Hey Whack-a, they gave you a polygraph test before they would hire you as a high school-age bus boy? Good God, was it the TGIF in Fort Knox or at the FBI HQ? That’s just amazing.

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Boy, this is a bit like in Hitchhiker’s Guide to the Galaxy where the computer told them the answer to the ultimate question of the life universe and everything is 42, but didn’t know the question. Isn’t it? You have to think about the answer first, then find the question that matches that answer.

Anyhoo, before you can think of the question that will correspond correctly to the lie, you have to figure out what answer is not going to look bad. In order for you to do that, you have to hear the question and think about it. And that is when the polygraph will get you. It doesn’t just check for lies the one instant in time when you answer. There is a human there that interprets what he sees. He analyzes the graph before and after you answered in order to claim it the truth or lie. Also, pauses don’t look good. If you know the truth and you are trying to prove it, then you should be able and willing to answer immediately. Pauses either make you look like you are considering what answer is going to look good, or what answer won’t screw up an earlier answer, or it will look like an attempt to control your stress level. Any of those are an indication of deceipt. Even if the answer is true, the interpreter might think you are lying.

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Oh! Also, Meet my Folks is in America now. I really like it. But that polygraph pisses me off. I know that guy who reads the little squiggles is just telling the parents what they DON’T want to hear. I hate that interpreter. He often changes the parents minds when I can tell that the girl/guy isn’t lying.