While reading SA Warner’s article, I noted that the inaccuracy and the false-positive rate of the polygraph were not discussed.  These are the core issues in my opinion.  The fact that so many law enforcement and governmental agencies base vital decisions on an inaccurate “test” which misidentifies as many truly deceptive people as it labels honest people as “deceptive” is the heart of the entire polygraph problem.  To simply gloss over that matter and switch the argument to whether the polygraph has any use at all in an interrogation setting with an unwitting examinee is specious reasoning.  It is analogous to arguing that an experimental medication which has been shown to worsen patient’s symptoms as often as it eases them is still useful because some patients improve when given the medication simply because they believe it will work (a.k.a. the placebo effect.)

I fully agree that the polygraph can be useful in an interrogation setting.  If the subject’s knowledge of the polygraph comes solely from movies and television (like most people) then he or she will most likely believe that any lie they tell will be detected.  In cases like that, the use or threat of a polygraph “test” may elicit a confession or admission that otherwise might have been withheld.

Having said that, I would have to qualify my opinion by saying that if I was interviewing a subject who grew up believing that crystal balls, tarot cards, or palm readings were effective at detecting falsehoods, each one of those would be just as effective as a polygraph in eliciting confessions or admissions from that subject.  Even SA Warner writes in his article: “any technique that examinees believe to be a valid test for deception likely can produce deterrence and admissions.”  However, SA Warner contradicts that statement when he writes: “Investigators do not want to waste their time with a lie detection technique that yields little more than speculative results.”

I must confess that I’m confused.  I thought the focus of the article was that, without delving into the accuracy or false-positive rate of the polygraph, it can still be useful as an interrogation tool because some people believe it will detect lies.  But the latter quote from the article seems to imply that the polygraph is superior as an interrogation tool because it is a lie detection method that yields better than speculative results.  Which is it?

With regards to the “archival research study” mentioned in the article, I must be more cynical than the author.  I would tend to give little if any credibility to a pseudo-scientific study conducted by FBI polygraph examiners on FBI polygraph examiners.  Perhaps we could also ask Big Tobacco to conduct further studies to see if nicotine is addictive?  Or we could ask McDonald’s to do some research to see if a high-fat, high-sodium, high-sugar meal is good for kids?

In the close of the article, SA Warner poses a question that is designed to make the reader stop and think.  The question is: if your child was kidnapped and the police had a suspect, would you want the suspect to be given a polygraph exam?  The dilemma inherent in that question, in my opinion, is not what would happen if the suspect was questioned and confessed or admitted to some involvement.  The dilemma lies in what would happen if he didn’t confess and in fact came back with a “no deception indicated” chart.  The police would most likely write him off as a viable suspect!  If he was a viable suspect to begin with he should never be cleared by a polygraph, crystal ball, tarot cards, or any other interrogation intimidator.  It simply should not happen.  But it does, in part because the polygraph has a false aura of credibility.  The same incorrect knowledge gleaned from movies and television that make the polygraph an effective interrogation tool on some people also make it a danger to use because of its inaccuracy.  In the example above, if the suspect passed the polygraph exam there is a real possibility that, in the minds of at least some of the investigators working the case, the suspect would no longer be investigated with the same zeal, because he’d already been “proven” innocent.  Witnesses might even change their story, convinced they’ve made a mistake because the person they thought they saw “passed” his polygraph.  The only way to counter that possibility would be to make widely known the details of the polygraph examination and why it works, in order to educate law enforcement officers and the rest of the public that it is ONLY valid as an intimidator during interrogations, and has no actual use as a “lie detector.”  If that ever happened, it would also educate the people who might someday have to take a polygraph exam, which would effectively nullify the value of the polygraph as an intimidator.