What is a polygraph test?

A polygraph test is a test used by a professional to determine a persons guilt or innocence. A polygraph test (lie detector test) can help to eliminate a person from suspicion or to confirm a persons guilt.

Who can take a polygraph test?

Anyone over 18 can take a polygraph test in Ireland; those under 18 can take a test but only with parental consent. Have you been wrongly accused of a crime or family betrayal? A polygraph test can help you to prove your innocence.

How does a polygraph test work?

The examiner takes account of a combination of a persons vital signs, reactions, sweat secretions, blood pressure etc. and reaches a conclusion on the results obtained. It is virtually impossible to beat a polygraph test there are cases but they are few and far between.

Please note that any person who is taking prohibited drugs should not take a polygraph test, nor should any person with heart problems, mental illness or even a cold or flu, as these things can compromise the accuracy of the test results.

What happens during the polygraph?

A polygraph takes from one to three hours depending on the subject matter. The person taking the test is asked a series of questions whereby the answer is already known to be positive or negative. They are also asked a few false negatives, i.e. questions the examiner knows to be untrue, for example asking a 30 year-old to confirm they are 22. Then the unknown questions are asked, and any deceptive answers will bring about physiological responses that can be differentiated from those produced by the truthful ones.

Some people worry that if they are nervous it may produce an inaccurate test result. This simply is not true, because those nerves will be evident throughout the interview process (and thus manifest in physiological responses) and not merely in the questions of importance.