Poet Bullucks   |    March 1, 2026

Why the Polygraph Test is not Dependable

In actuality, even though the Polygraph test can measure these responses, these factors actually do not guarantee whether the person is actually being dishonest. The lie detector test could possibly even tell when you are not lying. This is because a person that is lying and a person that is telling the truth has the same biological (and most psychological) reactions. They are both worrying, but about different outcomes. Either someone is going to get cause doing something unethical, or someone is going to get wrongly accused of doing something unethical. This included speeding of biological processes (sweating, heartrate, etc) or cognitive feelings and expressions (body language, shock, nervousness, high stress levels, etc).

This device has actually turned into a paradoxical reaction of working the opposite way of its intended to. Dr. Ben-Shakhar (2019) elaborates on this myth with a reasonable example on why the lie detector test would not work every time with a created “Did You Do It?” scenario. He explains that in a murdercase, if we were to do a lie detector test on an innocent and guilty person, it would be presumed that an innocent person would show the exact opposite affects and symptoms of a person who is guilty of the murder. However, that is not the case, for the same symptoms for detecting dishonesty are the same symptoms that can occur when people are speaking the truth. Guilty or not, any person would be surprised or nervous when being put on the spot if they conducted the crime, initiating the same biological responses of increased heart rate, breathing, blood-pressure, body heat, or arousal.

Conclusion

In other words, the Polygraph test is a myth and it can not detect dishonesty. It was never made to detect untruthfulness, but your natural biological and cognitive processes. In fact, there is no device that is able to truly tell if a person is being honest. However, the future could definitely amaze us with inventions which we never thought were possible.

References:

Ben-Shakhar, G. (n.d.). The Lie-Detection Myth. Psychology Today. https://www.psychologytoday.com/us/blog/memory-detection/201910/the-lie-detection-myth 

Law School, C. (n.d.). Lie detector test. Legal Information Institute. https://www.law.cornell.edu/wex/lie_detector_test 

Lilienfeld, S. O. (n.d.). 50 great myths of popular psychology: Shattering widespread misconceptions about human behavior (great myths of psychology): Lilienfeld, Scott O., Lynn, Steven Jay, Ruscio, John, Beyerstein, Barry L.: 8601200486643: Amazon.com: Books. Blackwellpublishing.com. https://www.amazon.com/Great-Myths-Popular-Psychology-Misconceptions/dp/1405131128