Lie detectors have become a well-recognized cultural image, easily identified by almost everybody, courtesy of advertisements and TV shows. If you have seen crime-related TV shows before, you will remember the pang of anxiousness during the scenes where a polygraph pen was shown haphazardly scribbling across a graph. Also, you may remember ‘Nothing But The Truth’, a popular show that depicted the use of the lie detector. Many have wondered, “

Do lie detectors work”. Unlike professional users whose occupations demand the service of lie detector tests, such as private investigators, most people are eager to know of the polygraph test accuracy.


How Does A Lie Detector Work?

As per experts, a typical lie detecting apparatus makes use of biologic reactions/physiological responses of a person. Mainly three elements are considered:

  • Blood pressure: A cuff is put around the subject’s upper portion of the arm, detecting the rate at which the blood is being pumped. The results are detected by the detectors, being drawn across the polygraph chart.
  • Respiration: Two air-filled tubes are wrapped around the person’s chest. When the subject breathes, their chest contracts or relaxes, a change which does not go unnoticed by the polygraph machine.
  • Skin conductivity: Also known as galvanic skin responses, this element makes use of the fact that skin resistance changes as the rate of sweating changes.

The end result is that if the person taking the test has increased respiration, or a quicker pulse or bouts of sweating, it will show up on the detector, indicating a lie.


Are Lie Detector Tests Accurate?

Lie detector reliability has been a hot topic that has seen debates for years now, with valid reasons. While there are previous lie detector customers, such as enterprises, firms, agencies and organisations who are satisfied with the results of polygraph testing, others are not. As a matter of fact, the truth behind the whole polygraph business definitely questions polygraph reliability.

There have been several instances when a person taking the test got away with telling lies, while others were wrongly accused. While a few of the failed tests could be a machine fault, others are due to the fact that the machine could not distinguish discomfort from stress due to lying. So, what does that say about the validity of the results of the lie detectors? Some individuals are put off by the polygraph testing, while others argue that a series of pre-test questions are asked, which allow the professionals to determine the truths and the lies. It is said that practiced clientele have a 4% chance of making errors, leaving us 96% lie detector test accuracy, which is still quite precariously high.


How To Beat A Lie Detector?

During the commercial use of polygraphs in the likes of job- or crime-related instances, the subject would make attempts to mask their biological reactions to their lies. Cheating in this manner rarely works out because one way or the other, the subject is bound to get caught.

Is a lie detector test effective? Based on the facts we have looked at so far, the answer is obvious. You would not want to be taking it if you are guilty of committing a crime.