Many people are nervous about taking a polygraph, and they may try to research the testing procedures on the internet. Sometimes they feel that they can “beat” the equipment by the use of popularly known deception techniques:
- One popular suggestion is to use antiperspirant on your fingers and palms. This is thought to impede the polygraph’s ability to gauge your sweat gland’s reactions. What actually may happen is that if the antiperspirant works it will prevent the machine from making any readings at all for that measurement. This is a tell-tale sign of deception. You will be told to wash your hands to clean off the antiperspirant, and the examiner will mark your test as attempted deceptive.
- Lie on the control questions – Some of the questions asked on a polygraph are only there to set a baseline for your tests. A control question might be something like “is there anything you hope I don’t ask you?” or “have you ever done anything you felt guilty about?” The advice goes if you lie on those questions, then the test won’t have a bona-fide basis for comparison. What actually happens is that the examiner will know that you are lying on the control question (for example everyone at some point in their life has felt guilty or lied about something). The examiner will simply select another control question to be used as a basis of comparison, and will know you are attempting to be deceptive.
- Changing your breathing patterns – Some internet authorities suggest that you can beat a polygraph by carefully holding your breath at critical intervals during the polygraph test or biting your own tongue. The problem is that most experienced polygraph administrators have been trained to look for these standard countermeasures and will know that you are attempting to be deceptive. Another problem is that unless you have access to a polygraph machine to practice on, and know exactly what the examiners are looking for in scoring your test, you will not be able to effectively control your breathing in such a way as to manipulate the outcome.
People who are considering trying to beat a polygraph may also mistakenly assume they only have to fool a machine. In reality you would have to fool a trained, licensed professional examiner who may have decades of experience in administering thousands or tens of thousands of test.
The best advice that we can provide to those who are considering whether to subject themselves to a polygraph can be easily summed up as follows:
- If you are the subject of a police investigation do not take a polygraph until you have retained a lawyer, passed a private polygraph and your lawyer recommends that you take the police test;
- This advice does not change even if you believe that you are being wrongly or unfairly accused of a crime. Polygraph tests are very accurate, but on rare occasions there are false-positive test results. No one should discover that they are not a good candidate for this test at the police station (when it is too late).
I frequently make use of polygraph examinations when I have a client that I think could benefit. I do this both for cases in the pre-arrest and post-arrest stages. I reason that there is no downside to a client who maintains that they are innocent of the charges to take a polygraph in my office. If they pass the results can be shared with the police or the prosecutor, and if they don’t pass then no one knows the test was even taken at all. Favorable results have helped my clients avoid serious charges such as child molestation, burglary, or murder.