Do Lie Detectors Lie?

The lie detector test, or polygraph, is not all you've made it up to be. Of course, on television, they often use the lie detector test as a means of getting the most correct answer and what not, but in all reality, the lie detector test often lies. Through psychology and many studies, the accuracy of the lie detector test has been disproved on multiple occasions. If you're interested in how the lie detector works, the accuracy and precision of it, or devastating cases the lie detector has caused, read on!

If you've ever read or probably even heard about the lie detector test, you probably know somewhat how the machine works. However, you're probably also led to believe that the test is completely accurate because of the way it works and measures your body's perceptions.

The polygraph measures several physical responses that accompany emotion, such as changes in breathing, cardiovascular activity, and perspiration. While you're attempting to relax, the examiner will ask you questions, and measure whether or not you're telling the truth based on the fluctuation of these things. The only problem is, if you're taking a lie detector test, especially if it's a subject that could potentially worry you, you're going to be under some extreme stress. Your heart will probably beat faster naturally, you're probably going to breath faster, and sweat more. So how can the test be accurate under these conditions?

These tests error about 1/3 of the time, including the time when innocent testers are put under such stress that their body cycles change just due to the fact that they're under such stress, regardless of whether or not they're actually telling a lie.

No spy has ever been caught using a polygraph, according to a 2002 U.S. National Academy of Sciences. It definitely isn't for lack of trying, either. The FBI, CIA, and Departments of Defense and energy in the United States have spent millions of dollars testing tens of thousands of employees. Even with all of this testing going on, Aldrich Ames, a Russian spy, went unnoticed in the CIA. He passed all of the lie detector tests given to him. So what good are lie detectors really even doing?

In a recent survey, more than 9 in 10 psychophysiologists and research psychologists agreed that savvy criminals and spies could beat the lie detector test by augmenting their arousal to control questions, such as by biting their tongues. If people have learned to control the lie detector test, anyone could. So what is its efficiency? Why do we even bother to use it, when the people that could control the lie detector best know how? The accuracy of it is a mere joke, if you look at it in that way.

However, there is new research about the polygraph that may give us some hope! The guilty knowledge test is definitely a more effective means of capturing a criminal. This assesses a suspect's physiological responses to crime-scene details known only to the police and the guilty person. Lets say a camera was stolen. The guilty person would react very strongly to the specific brand of this camera if it were brought up in the lie detector test. Given really specific questions, it's highly unlikely that an innocent citizen could be wrongly accused.

In my opinion, you should really just avoid the lie detector test if you're innocent. Don't stress too much about its effectiveness, as with all of this research and groups involved on fixing it, it'll be as accurate as the public believes, soon enough!