Polygraphs: The Real Lie

Are "lie detectors" reliable determiners of the truth?

NO! Of course, they sometimes "work," since much of the time they are used to scare people into confessions or admissions of guilt. But they are very unreliable as a way of detecting lies.

After 9-11, the polygraph failure rate went to 50% for agent applicants at the FBI. Did liars suddenly start applying for jobs? No, but the testers were instructed to read the tests differently. Unfortunately this meant throwing out some honest people with the few dishonest ones.

Imagine what this would do to your future. For all of their lives these mostly innocent people will have a record of a failed FBI polygraph following them. Think about that before agreeing to take such a test.

Most scientists now agree that polygraph "testing" is junk science. In fact, John Larson, one of the pioneers of polygraphic lie detection, says "I'm sorry I ever had any part in it's development." The test is valued by governments and others because it is useful for getting damaging admissions from people, especially those who don't know that the test is a sham.

What do officials have to say about "lie detectors" ?

"[The CIA's] reliance on the polygraph is truly insane." 
- John M. Deutch, former CIA Director

"...the use of this highly flawed instrument should be radically curtailed." 
- R. James Woolsey, former CIA Director

Unfortunately, the test is actually  biased against the truthful. This is because the more honestly one answers the "control" questions, the more likely one is to fail. Meanwhile, hardened criminals have proven they can lie throughout the test without detection.

In fact, there isn't even agreement among believers in the polygraph as to why it works. There are three common theories.

The first theory is that a subject reacts when questions that strike sensitive areas, whether he is telling the truth or not. This theory would indicate that your nervousness (natural under the circumstances, right) might be taken as dishonesty.

The second theory is the theory of conflict. It supposes that a measurable physiologic disturbance takes place when a subject is caught between a habitual inclination to tell the truth and a strong desire not to admit to certain actions of facts. Some researchers think that if this concept is valid, it is only when conflict is intense. Of course habitual liars may be measured as honest in this case.

The third, most commonly accepted theory, is the "threat of punishment" theory. It says that a large physiologic response accompanies lying because a subject fears consequences for failing to deceive the operator. In other words, a subjects own fear of failing is what causes the response. The problem that many researchers note is that one who does not fear the results of his failure should not produce measurable responses.

Experts argue about why the polygraph works, scientists call it junk science, pioneers in the field regret their involvement in its development, and CIA officials think it is unreliable. Does the polygraph test or "lie detector test," work? It is clear that it does not work with any consistency.

It can be dangerous to your freedom and reputation to take it - even if you have nothing to hide.