Retired FBI polygrapher Barry Colvert performing for the camera in Harsh Times
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:
Quote:Mike: How you gonna pass the lie detector test, you lyin' mother crappity smacker?
Jim: Oh, easy man! After every question, you just squeeze like you're takin' a dump, you know man? It throws the machine off!
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.
Jim in the hot seat.
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:
Quote:Is your name Jim Luther Davis?
Do you live in Los Angeles?
Are you 26 years old?
Are you married?
Are you wearing shoes?
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:
Countermeasures?
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.