A polygraph test, also known as a lie detector test, is a test used to detect whether someone is telling the truth. The test is usually used in situations where there is a potential for fraud or deception, such as in a job interview. The polygraph test is based on the principle that lying is a stress-inducing activity. The theory is that when a person lies, their heart rate and blood pressure will increase, and they will perspire more. The polygraph test measures these physiological responses to determine if a person is lying.

One of the main criticisms of the polygraph test is that it is not always accurate. There are many factors that can affect the results of the test, such as anxiety, fear, nervousness, and medication. Additionally, the test can be influenced by the interviewer’s own biases and beliefs.

Despite its shortcomings, the polygraph test is still widely used as a tool for detecting deception. In many cases, it is the only evidence available to investigators. In other cases, it is used to corroborate other evidence. For example, if a suspect has a history of lying, a polygraph test may confirm their guilt.

The cost of a polygraph test

A typical lie detector polygraph examination is anywhere from$900 -$1,500+, with an average fee of about $1,250.

In conclusion, a polygraph test is a useful tool for detecting deception, but it is not perfect. There are many factors that can influence the results of the test, and it should not be used as the sole evidence in a criminal investigation.