Lie detectors are devices that measure the involuntary physiological changes of a person as they respond to a question or statement. They include measures of heart rate, blood pressure, respiration, perspiration and skin conductivity.
Generally, lie detectors are used to find out whether someone is telling the truth or not. These tests are commonly used by police, hospitals and law firms. URL liedetectors.co.uk
In addition, these tests are also used by employers who need to ensure that their employees are trustworthy. These tests are very accurate and have a success rate of 90% or more.
The History and Evolution of Lie Detector Technology
Some people believe that lie detectors are only used in Hollywood productions or police stations. However, they are actually used all over the world and can be useful in a variety of situations.
Polygraphs, the most popular lie detector, were first developed in the 19th century. They were originally designed to detect blood pressure, but later added the ability to measure galvanic skin resistance (which is a good indicator of sweat) and breathing rate.
The basic idea behind a lie detector is that when people tell lies, their stress levels are different than when they are truthful. This is because they are anxious, which causes their fight-or-flight response to kick in.
But a lot of psychologists have called this theory into question. Psychologist Leonard Saxe has argued that the underlying psychophysiological theories behind lie detectors are more myth than science. Moreover, studies have shown that lie experts, such as police officers and customs agents, are no better at detecting lies than lay people are.