With all of the different information swirling around about lie detectors, one may wonder how effective they actually are. Can law enforcement really use lie detectors to discern whether or not someone is telling the truth? Not everything you’ve heard about lie detectors is a fact, which is why the attorneys at Andrew Beasley are discussing the most popular myths about these machines.
In this blog, you’ll learn how lie detectors work and be able to tell facts from fiction the next time you’re watching your favorite crime show.
What Are Lie Detectors?
Also known as a polygraph, a lie detector is a tool or process used to measure and record various physiological signals like blood pressure, pulse rate, respiration, and skin conductivity. This monitoring takes place while an individual is being asked a series of questions and providing their answers. The use of the polygraph relies on the belief that when someone gives deceptive answers, their body will exhibit physiological responses that can be distinguished from those associated with truthful answers.
These devices often appear in real-life investigations and crime dramas where the truth must be revealed. Lie detectors are surrounded by myths and misconceptions that have twisted our understanding of their reliability and accuracy.
The Most Common Myths About Lie Detectors
Myth 1 - Tricking a Lie Detector
Many people think a lie detector test can be tricked, giving individuals a reason to deceive the examiner and manipulate their responses. This perception has been prolonged by movies where the protagonist is ingeniously intelligent and able to outsmart the polygraph test. Viewers are left with the impression that such deception is easy, but the reality is much different.
The truth is that lie detectors are not easy to fool. Psychological responses like respiration, blood pressure, skin conductivity, and heart rate are measured to detect nervousness and stress. These naturally occurring physical responses are difficult to control and skilled examiners must go through training to be able to differentiate between deliberate attempts to manipulate the tests and genuine physiological reactions. These examiners are trained to identify tactics like physical discomfort and controlled breathing that could momentarily alter results.
Myth 2 - Lie Detectors Detect Lies Directly
Contrary to popular belief, a lie detector cannot directly detect lies; rather, it calculates bodily responses such as nervousness or stress, and that could suggest someone is lying. This calculation is based on the assumption that when a person lies, they have heightened physiological arousal. The fear of being wrongly accused or discomfort can trigger this arousal to confirm the assumption.
Note that interpreting a lie detector result is a complicated process that requires the examiner to look into various factors. The result should be used in conjunction with other investigative methods and pieces of evidence for accuracy.
Myth 3 - Infallibility of Lie Detectors
The myth that lie detector machines are infallible and can determine lies without any doubt is as old as the test itself. If lie detectors were completely accurate, many criminal cases could be solved within minutes. The reality is that these machines are not reliable and have been known to produce false negatives and false positives.
Emotional states, medical conditions, and individual physiological baselines can influence lie detector results and accuracy. An innocent person exhibiting nervousness due to fear or anxiety of the test leads to a false positive; in contrast, a skilled liar who remains calm under the pressure of the test leads to false negatives. Lie detector results are considered indicators instead of deception or definitive proof of truth.
How Can Lie Detectors Be Useful in Real-Life?
Despite the limitations of a lie detector test, it has practical application in specific contexts. These machines are used during employment screening for specific job roles, particularly those that involve sensitive information or high security. Additionally, law offices and law enforcement agencies often use polygraphs to gather information and assess the credibility of suspects or witnesses during a criminal investigation.
Individuals on probation or court-ordered treatment programs might be subjected to lie detector tests to monitor compliance. In this case, they will need a criminal defense attorney to be present during the process. Understanding the limitations of a lie detector is crucial for maintaining a just and fair legal system and helping criminal defense attorneys with their cases.
Andrew Beasley is Your Criminal Defense Attorney in Nashville, TN
At Andrew Beasley, we believe every criminal case is unique and deserves personalized solutions. That's why our dedicated team treats each case with attention and care. We offer free case reviews and consultations to ensure that you are fully satisfied with your decision to hire one of our skilled attorneys. During our appointment, we will take the time to thoroughly analyze your case and provide you with a comprehensive explanation of our plan moving forward. Rest assured that we will guide you through each step of the process, ensuring that you are fully informed along the way.