A Brief History of the Lie Detector Test

In this article we look at how lie detection techniques have evolved over the last century...


  1. How do Lie Detector Tests Work?
  2. History of the Lie Detector Test (Polygraph)

    If there’s one thing synonymous with lie detection and lie detector tests it’s the polygraph machine. Whether you’re watching factual or non-factual television or film there’s always one thing you’ll see should there be a lie detector test being a conducted - a polygraph. But why have they become so prevalent in the field of lie detection and how did they come into existence? In this article we examine both of these questions, so if you’re interested in this area of science then this article is for you.

    1921 is commonly acknowledged at the humble beginnings of polygraph machine as we know it today. Whilst previous physiological testing was mainly limited to pulse-rate and blood-pressure readings, a psychologist called John Larson (who was employed by the police at the time) added respiration rate to the testing procedure (Dr. William Marston is credited as creating the first lie detector machine 6 years prior, which utilised blood-pressure readings). He then proceeded to name the instrument a polygraph which in Greek translate as ‘many writings’. Larson went on to use his polygraph during many investigations and had much success doing so.

    Four years later in 1925, the polygraph evolved once more when Leonard Keeler (who had worked with Larson) set out to reduce the bulky size of the polygraph as well as update the method by which it recorded its data. Keeler soon managed to complete what he had set out to do by creating a less cumbersome machine that used ink to document its output readings. Many years later in 1938 he made further alterations to the polygraph by adding what called a ‘psycho galvanometer’ - a tool that was able to detect changes in the electrical resistance of a subject’s skin. Once this was added to the machine the polygraph as we know it today was created (albeit a cruder version). Keeler went on to establish the world’s fist polygraph school in Chicago.
  3. Lie Detector Tests - Are they still relevant?
    Lie Detector Tests - Are they still relevant?
  4. Modern day lie detector tests don’t just consist of machine based techniques. Interrogation and questioning methods are vital to ensure as accurate a result as possible, and the beginnings of this can be traced back to the late 1940’s. An American lawyer named John Reid devised what he called CQT (Control Question Technique) that was designed to be emotionally stimulating for non-deceptive people and less so for those not telling the truth. Reid’s introduction and use of this technique was hailed as a major breakthrough in lie detection methodology.

    By the time the 1980’s had come around experts in the field of lie detection had started to consider the use of a computerised polygraph with the University of Utah being the leading establishment in this area. John Kircher and David Raskin created a system known as CAPS (Computer Assisted Polygraph System), which was an algorithm created for the purpose of evaluating the data collected from Polygraph machines. Some ten years later the first fully computerise polygraph was built and made its way into the market.

    In more recent times there have been several studies into polygraphs and their accuracy. The U.S Department of Energy’s 2003 study conducted in accordance with The National Academy of Sciences sought to analyse all previous data collected from polygraph research (they chose not to carry out any further tests due to the fact that recreating the scenario in which a lie detector would be used is all but impossible). The review concluded that whilst there may be other techniques for lie detection, none of them are able to outperform the polygraph nor is there any evidence to show that they are capable of doing so either in the present or in the future.

    We can therefore say that with over a hundred years of science and research having gone into polygraphs (and their associated lie detection methods) they remain the number one choice for lie detector tests.

    Find out more at: liedetectortest.ie