As a West London polygraph examiner I see misconceptions about lie detector tests all over the internet.  Occasionally they infiltrate newspapers and other media outlets.  It’s time we dispelled them to present a more balanced view. Here are some of the most common misconceptions.

Lie detector tests detect lies

No they don’t. Lie detector tests detect deception by monitoring psychophysiological responses to professionally formulated questions. Polygraph equipment detects changes in respiration, cardiovascular and electro dermal activity.  The latter relates to perspiration that alters the electrical properties of the skin.

Arguments that these responses are present in other situations when a person is not lying are valid. Natural anxiety can cause psychophysiological responses that are similar if not the same.  However, professional polygraph examiners take natural nervousness into consideration before the test is administered and the equipment is set accordingly.

Polygraph examination results are not wholly reliant on the equipment. The qualifications and experience of the examiner are equally important in the process.  Let’s face it, when you need a professional carpentry job done, you are not going to employ a hammer. You will employ a qualified carpenter who wields the hammer and knows what he is doing with it.  Likewise, you don’t use a polygraph machine without a highly trained examiner.

Polygraph tests don’t work

This misconception comes about because those stating it already believe that the polygraph detects lies. As previously mentioned it doesn’t.

However, it works extremely well as an investigate tool.  If this wasn’t the case it’s hardly likely that the Ministry of Justice in the UK would make taking tests a compulsory condition for certain types of offenders when they are released from prison on licence.  It’s even less likely that many UK police forces would use them for monitoring purposes yet they do.  Indeed they have become increasingly utilised in recent years.

In the justice system the polygraph is instrumental in pointing detectives in various directions to enhance their investigations. For example, a condition of a paedophile’s release may be that he must not access or download images from the internet. Questions can be asked in periodic, compulsory lie detector tests to ascertain whether he has broken that condition.  If deception is found, the computer will be confiscated and forensically examined.  Depending on the result of the examination he will be returned to prison to serve the remainder of his sentence. Since these polygraph tests have been implemented more than 160 offenders have been sent back to jail. The polygraph is working extremely well in these cases.

You can beat a lie detector test

As a West London polygraph examiner and qualified forensic psychologist I have to admit to being amused by attempts to do this.  The favourite is to trying putting a drawing pin in the shoe and then pressing down on it when certain questions are asked. The theory is that these responses will either produce inconclusive results or achieve a pass.

It is quite difficult to keep a drawing pin in your shoe and walk.  I have had subjects walk in to my office on tiptoe, a feat worthy of professional ballet dancers.  In the pre-test interview I have seen subjects attempt to insert a drawing pin into their shoe pretending to scratch their ankle.  Overcoming this stupidity is very easy.  I don’t test people with shoes on.

My training in forensic psychology has provided me with the ability to spot a scammer a mile away. A person searching online “how to beat a lie detector test” clearly doesn’t have the foresight to realise we can read too.

The aforementioned are the most common misconceptions but in addition there is confusion regarding the use of polygraph results in courts.

Lie detector test evidence

Polygraph evidence isn’t often used in courts but it has been responsible for turning frustrating investigations into successful ones. When detectives reach a dead end the polygraph can open new avenues for them to investigate.

Whether polygraph evidence can be used in court is up to the judge presiding over the case.  However, just as a judge wouldn’t convict on solely eye witness testimony, he or she wouldn’t do so based solely on polygraph results.  All evidence of any type has to be backed up with other evidence for a successful prosecution or defence.

Lie detector tests can always be mentioned in court and are often allowed in industrial tribunals.

Contact West London Polygraph Examiner

If you would lie to learn more about how polygraph services are used within the public, private or commercial sectors keep an eye on the blog or contact our free helpline on 07572 748364 . Our services are not only confined to West London but are nationwide.