A lie detector, also known as a polygraph test, is an electronic device that measures heart rate, perspiration, and blood pressure, reactions that are associated with lying. It was invented nearly a century ago by William Moulton Marston.
Despite their popularity, polygraph tests can be misleading. Many innocent people have been convicted due to faulty results from these tests.
It’s not a legal obligation
You are never under any legal obligation to take a lie detector test during a criminal case, even if the police tell you it’s mandatory or threaten to arrest you if you refuse. In fact, volunteering for a test to prove your innocence can be dangerous because the results are not guaranteed to be accurate.
The basic idea behind a polygraph is that people who are lying will show measurable physiological responses, such as increased perspiration and heart rate. However, this theory is flawed because lying causes many different types of reactions, and not all of them are measurable. For more info I’ll suggest you visit the website Lie Detector Test.
Additionally, certain medical conditions and drugs can skew the results of a lie detector test. For instance, a person who suffers from epilepsy may have trouble controlling their responses, and pregnant women can experience a rise in blood pressure. Moreover, the Employee Polygraph Protection Act prohibits most private employers from using polygraph tests for pre-employment screening.
It’s not a good idea
Whether you’re a suspect in a criminal investigation or have been cleared of all charges, you’re not under any legal obligation to take a lie detector test. In fact, it’s usually not a good idea to agree to one – especially after you’ve been accused of a crime – without first consulting with an experienced criminal defense lawyer.
A polygraph, or lie detector, measures a subject’s blood pressure, pulse rate, respiration, and perspiration responses to questions asked by the examiner. The theory is that liars show greater arousal than truth tellers, and the machine can determine that difference.
However, the underlying premise is flawed. Various experiments have shown that people can alter their results to pass a polygraph test, including taking sedatives to reduce anxiety, applying antiperspirant to counter sweating, and breathing deeply after each question. Even the notorious Green River Killer and Russian mole Aldrich Ames beat the polygraph. It is also known that racial bias can affect the results of a polygraph.
It’s not reliable
Lie detectors (or polygraph tests) measure a person’s physiological responses to questions. The theory is that when a person lies, their body will exhibit specific reactions, such as increasing blood pressure, heart rate and perspiration. The machine then records these reactions and produces a graph of the results.
Unfortunately, the science behind polygraphs is flawed. The tests are not accurate or reliable, which is why they are rarely admissible in court. Furthermore, a person can fail a polygraph simply because they are nervous. Frequent liars tend to be better at lying, so their body’s response to the test may be more subtle than that of an innocent person.
It is possible to beat a polygraph, but only if you have a trained examiner and the right strategy. Otherwise, you’ll likely just end up being agitated and scared. That won’t do much good if you’re trying to prove your innocence. In any event, it’s best to avoid taking the test altogether unless absolutely necessary.
It’s not accurate
Lie detector tests, or polygraphs, measure the subject’s physiological responses to questions. They typically include sensors to measure heart rate, blood pressure and perspiration. They are often used by employers and criminal investigators, although they can also be used in the context of a civil lawsuit or for certain government jobs.
The accuracy of these tests has been called into question for as long as they’ve existed. Some experts believe that the machines can be beaten by liars who are able to control their typical stress responses, such as increased heart rate or blood pressure.
In addition, a person’s results may be affected by non-verbal cues that are associated with lying. In fact, the infamous Soviet spy Aldrich Ames was able to pass his test by following his Soviet bosses’ advice to “simply relax.” Moreover, these tests are only as accurate as the examiner, which means that they can be misleading. You are never under any legal obligation to take a lie detector test, and you should always consult with an attorney before agreeing to do so.