Mr. Mashcke,

If you have time, please watch the movie Harsh Times, in which a Department of Homeland Security applicant fails his polygraph exam. In the movie, a real life retired FBI polygrapher administers the test. 

In case you cannot access the film, I will give you a summary of the polygraph scene. The test starts with the polygrapher asking Jim if that is his correct name, followed by his address, followed by asking if Jim is married (Jim answers 'no' truthfully), followed by have you ever smoked marijuana (Jim answers 'yes' truthfully), followed by have you ever smoked marijuana besides the times you listed on the forms (to which Jim lies by saying 'no').

Right as Jim answers 'no' the camera shows the polygraph computer's needles dropping dramatically. You see a glimpse of the results from the previous questions, and it appears that Jim was using countermeasures to raise the results. After Jim lies, the camera then cuts to the polygrapher's face who then says "Jim, knock it off. I've been giving polygraphs since you were a sperm in your daddy's balls, and I know all the tricks. You've either got a tack in your shoe, or you're squeezing your butt. Now, if you do it again, I'm going to end the test and report that you were uncooperative." Jim says nothing, and it is later discovered that Jim failed the test.

My question to you is, what exactly did Jim do wrong? Besides the fact that he attempted to lie on the polygraph. I know that your intention is to prevent false negatives, but I would like to know where Jim went wrong. Thank you in advance.

I've reviewed the polygraph scene from Harsh Times. It is loaded with what can only be deliberate disinformation about polygraph procedures and countermeasures. The short answer to your question (what exactly did Jim do wrong?) is that he augmented his reactions to a relevant question instead of to control questions.



The disinformation about countermeasures begins with Jim telling his best friend Mike about how he's going to pass the lie detector test he'll be taking the following day:

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Those who have read and understood The Lie Behind the Lie Detector know that this countermeasure approach is deeply flawed. One should only augment reactions to the control (also called "comparison") questions, not to all questions.




Next, the film deliberately disinforms viewers about the nature of "control" questions. Colvert falsely introduces a series of questions as control questions. In fact, they are irrelevant questions, and would not be scored:

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Federal law enforcement agencies don't use any technique that includes five consecutive irrelevant questions. The main technique used is the Law Enforcement Pre-Employment Test (LEPET), which includes a mix of relevant, control, and irrelevant questions. But never five irrelevant questions in a row.

After the question about smoking marijuana "aside from the instance [he] mentioned in his application," which Jim untruthfully answers "no," Colvert intones: "Jim, knock it off." Jim sheepishly asks, "What, sir?" Colvert goes on, "Son, I've been doing polygraph examinations since you were swimming in your daddy's balls. So I know all the tricks. You've either got a tack in your shoe, or you're clenchin' your butt. I've got spikes all over this thing. If you do it again, I'm going to void this test, and report that you were uncooperative. Do you understand?"

Let's take a look at the polygraph chart that Colvert's character has in front of him:




Note that there are only four channels on the polygraph tracings, from top to bottom: thoracic and abdominal breathing, electrodermal, and cardiovascular. There is no channel for a seat pad or strain gauge such as might be used in an attempt to detect such countermeasures as a tack in the shoe or the anal sphincter contraction.

On the electrodermal channel, we see unnaturally vertical spikes that were clearly produced not by the examinee, but by the polygraph examiner himself making manual adjustments to the polygraph instrument. And at the end of the chart, we see a massive spike on the pneumo channels, coinciding with a similarly large drop on the cardio channel.

The reactions we see on the chart are not what we would expect if the subject were "squeezing like [he's] takin' a shit" on every question -- as wrongheaded as such a countermeasure approach would be.

No polygrapher -- including Barry Colvert -- has ever demonstrated the ability to reliably detect the kinds of countermeasures described in The Lie Behind the Lie Detector.

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Detecting deception via the polygraph isn't reality either.