Lie Detector Test

For more than ten years, Joseph Carlsberg led what you would call a double life. In one life, he was a 20-year veteran with the FBI and had access to some of the most-classified information in the nation. While in his other life, he was allegedly spying for the Russian’s. This deception of Carlsberg’s was finally discovered and he was later arrested and finally pled guilty to espionage. Yes, spies are probably the best liars in the world – they have to be, it is their job!

Indeed, most of us tell lies in our daily lives, even if it’s a simple matter of telling a good friend that his or her horrible new haircut ‘ looks decent’. Yes, people deceive others and tell lies for a number of reasons. In most cases, lying is used as a defense mechanism to avoid getting into trouble with figures of authority, bosses or even the law. Sometimes, it is easy to tell if someone is lying or not, but there are times when all of us tend to fall for these lies.

Polygraphs or lie detectors are instruments that are used to monitor the concerned person’s physiological reactions. On the contrary to what their name suggests, these instruments do not detect lies. They are only used to detect whether a person is displaying deceptive behavior.

How do Lie Detectors Tests work?
A lie detector is basically an instrument that is a combination of various medical devices that are put together to monitor any changes that might occur in the human body. As the person is being questioned about a particular incident or event, the examiner will check to see if the person’s blood pressure, heart rate, respiratory rate and electro dermal activity has changed as compared to the normal levels. Fluctuations in these levels may indicate deceptive behavior on the person’s part, but lie detector test results are kept open to interpretation on the part of the examiner.

Lie detector tests are generally associated with criminal investigations, but there have been many instances in which they have also been used for other reasons. There might come a day when you will also be subjected to a lie detector test before being hired for a particular job. Some private sector employers and many government entities have now started asking candidates to undergo a lie detector test prior to employment.

Lie detector tests are basically designed to look for any significant involuntary responses that might go on in a person’s body, especially when he or she is subjected to high levels of stress. These tests however, do not detect specifically whether a person is lying. But, there are certain specific physiological responses that most people undergo when trying to deceive another person. By questioning the person about a particular issue and examining the person’s physiological reactions to these questions, an examiner can then determine if the person is being deceptive or not.

In the last decade, the lie detector has indeed undergone a very dramatic change. For many years, lie detectors were those instruments that you probably saw in movies with those tiny little needles scribbling lines on a scrolling paper. Those were analog polygraphs. Today however, most lie detector tests are fully administered with digital equipment. The scrolling paper has now been replaced with computer monitors and sophisticated algorithms.

When you sit for a lie detector test, several wires and tubes will be connected to your body in certain places so as to monitor your physiological activities and responses. Deceptive behavior will most certainly trigger off certain changes in the physiological activity, and the examiner will detect this. The examiner will look for the amount of fluctuation in these physiological activities. Some of the physiological activities that are monitored are:

• The respiratory rate
• The heart rate and blood pressure
• Galvanic skin resistance

Some lie detector tests also detect if there are any arm and leg movements. As the examiner is questioning the person, signals from the sensors that are connected to the body will record these movements on a single strip of paper.

Detractors of the lie detector test call this practice something akin to voodoo, saying that lie detectors are no more accurate than flipping a coin to see if a person is lying or not.

However, the lie detector does not measure whether or not a person is lying, it simply measures changes in breath rate, blood pressure and perspiration rate, but these physiological changes can also be triggered off by many other emotions.

Yes, lie detectors do not detect lies. What has actually happened is that over the years, the media has dubbed this practice as lie detection and this is how the lie detector got its name. But from a scientific perspective, it is not possible to detect lies. However, the polygraph does detect deceptive behavior being displayed.

If the examiner is trained properly and has the necessary experience, he will be able to determine whether or not the individual is demonstrating deceptive behavior.