How it Works

 How Lie Detecting Works

‘Lie Detecting’ from data collected by the Voice Stress– or Polygraph equipment, is actually not what term implies. Here is How it Works…

The data collected is purely indicators of physiological reactions, and  IS ACCURATE. Presuming that a lie is the only reason for a reaction in the physiology, is however incorrect.

There is to this day no known device which measures physiological or psychological activity that is capable of directly recording a lie.

With both Voice Stress Analysis and Polygraph the examiner formulates and makes use of  irrelevant questions (known truths), control questions (known lies) as well as relevant questions pertaining to the issue in question.

How lie detecting works
Polygraph data capturing is now digital

Commissioner Gill Loveday in her article (Polygraph Tests – Where Does The Truth Lie? 2001; 2, 3,4) notes that in both methodologies “testing is based on the fundamental premise that a truthful person will respond more (show greater physiological response to) the control questions, whereas, the guilty person will respond more to the relevant questions. The test assesses the individual’s credibility by looking for a different reaction between the two types of questions. The underlying rationale being that people will channel their fears and anxiety to what they perceive as the biggest threat”.

Deception Indicated (DI) Results only indicate that there was significant reaction to the Relevant Questions, not that the subject was lying about having committed the act – this is How Lie Detecting Works.

‘Lie Detection’ is comprehensive and consequently an involved profession.  An examiners’ training should be traceable. All our examiners are members of applicable associations that require full adherence to universally accepted detection of deception protocols.


Voice Stress and Polygraph are equally accurate, either method is used in Screenings. Screenings are when we test a large number of subjects for general criminal activities or deviant behavior.

Pre-employment Screenings for new staff; questions usually cover substance use, verifiable qualifications, theft, involvement in crime, etc.

Together, these two types of Screenings form an effective Honesty Management Program.

Specific Tests

To test a short list of employees suspected of involvement in a singular incident, the 3 Chart Single Issue technique is used. Additional information such as camera footage, witness statements should therefor support a suspicion.

In conclusion, choosing which Lie Detecting Method to ask for, depends on various factors and personal choice.

Why shop around taking unnecessary risks if you can go directly to the industry leaders?

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