Tests for Compulsive Lying

Polygraph tests are not considered reliable.

If you have ever met someone who has trouble being truthful, you may be thinking that tests for compulsive lying would be a good idea. There are no specific tests for revealing a compulsive liar, but there are signs you can look for when trying to evaluate whether someone is being truthful.

Tests for Compulsive Lying: Polygraph Tests

Polygraphs are commonly known as "lie detector tests", but the truth is that they don't actually indicate whether a person is lying. Instead, a polygraph measures the person's physiological responses as they are being asked a series of questions.

Physiological Responses

The polygraph test measures these types of physiological responses:

  • Blood pressure
  • Respiration
  • Pulse
  • Skin conductivity (This measures the electrical resistance of the skin and the degree to which that skin opposes an electrical current.)

Testing Procedures

The polygraph testing starts out with an interview of the person being examined. The information taken from the interview will be used to write some control questions. The subject will also be asked to deliberately lie so that his or her response in that kind of situation can be noted. (The tester must be able to determine that the person was lying.) The next step is to ask the subject a series of questions. Some of the questions asked will be ones that the person will be expected to answer truthfully such as "Is your name Peter Finley?", while other questions are ones that most people will probably lie about such as "Have you ever stolen anything?"

Other questions being asked are the ones to which the tester is really interested in getting answered. The person will pass or fail the test based on a comparison between the way he or she reacts to the questions where the subject will probably lie and the ones that are specific to the case in question. If the physiological responses are more pronounced when asked the specific questions, the person is presumed to have lied when answering them.

Compulsive Liars and Polygraph Tests

Since the polygraph test is designed to look for changes in a person's responses, it is possible for a person who is a compulsive liar (and quite comfortable with saying things that are not true) to "beat" the polygraph test. Since these machines are not designed as actual tests for compulsive lying, they are not the most practical (or accurate) way to find out whether someone you know is lying. You will need to find other ways to figure it out.

Other Ways to Detect Lying

Here are some other (non-scientific) ways to detect lies that you can be on the lookout for:

  • Watch for a fake or forced smile.

When a person offers a genuine smile, it involves more than just the lower part of their face. They will appear to be relaxed and happy, and their whole face will light up. A genuine smile will usually mean that a person will show their teeth even if only a little bit.

  • Be suspicious of too much detail.

The truth can be quite simple to state, and a person who adds way too much detail to their account may be lying.

  • Look for excessive sweating.

Lying can make people nervous, and this often leads to more sweating than usual.

  • Watch for eye contact.

A person who is lying may be able to maintain eye contact with another person, so that may not be a sure sign. A person will break off eye contact and look upward if they are trying to remember something, and this is a normal reaction and not a sign of lying.

  • Pay attention to body language.

A person who is lying may unconsciously turn away from the other person they are speaking with or place an object in between themselves and the other person.

None of these indications can be considered reliable tests for compulsive lying, but they are signs of which you should be aware when you suspect someone is habitually lying to you.

Tests for Compulsive Lying