Is There A “Lie Detector” in the Polygraph?

Lies have been a part of human communication since the beginning of time. We have also attempted to distinguish between the truth and these falsehoods, a necessity that was exacerbated when cultures established legal frameworks. Law enforcement and other investigative organizations are aware that humans are not very good at determining the truth, but we do have the ability to develop technology that can pick up signals that are beyond of our range. The polygraph was the first device for truth verification, demonstrating that technology might be used to identify dishonesty. But how does this technology function in the modern world?

The Polygraph’s Historical Background

The phrase “lie detector,” which was once applied to the polygraph, is misleading. Although there is no reliable scientific method for lying detection, it is possible to quantify the psychophysiological responses that lie-related stress causes. The polygraph and other, more sophisticated truth-verification technologies were inspired by this idea.

Using a plethysmograph to assess respiratory and cardiovascular responses, Italian scientist Angelo Mosso studied people’s physiological responses to questions in 1878. His study was taken up and enhanced by other scientists.

A polygraph was created in 1921 by Canadian psychologist John A. Larson when he was employed by the Berkeley (California) Police Department. He called the tool “polygraph,” derived from the Greek word “polýgraphos,” which meaning “many writing.” The pulse, breathing, and blood pressure were recorded and plotted by the polygraph. In 1938, Leonarde Keeler made additional improvements to the apparatus by including sensors to gauge the galvanic skin reaction.

With sensors placed on the body, such as a blood pressure cuff to measure heart rate and blood pressure, pneumograph tubes to measure respiration, and galvanometers attached to the fingertips to measure perspiration, the modern polygraph model functions essentially in the same way as those developed nearly a century ago.

John E. Reid, a Chicago attorney, improved the polygraph procedure in the late 1940s. Reid went on to create the Reid Technique, a method for questioning and interviews that law enforcement frequently use, either with or without a polygraph test.

The polygraph of today is digital, and although it employs the same sensors and basic idea as the analog model, it analyzes the data using an algorithm before charting it on a computer program.

Vulnerabilities in Polygraphs

William Scott Stewart, a Chicago attorney, authored an essay titled “How to Beat the Lie Detector,” which was featured in the November 1941 issue of Esquire Magazine. Stewart noted that you could rig the polygraph by being more emotional in response to innocuous questions, making this likely the first essay of its sort to focus on countermeasures to the test. These “control questions” are intended to serve as comparisons to the pertinent questions and are asked during the Control Question Test (CQT). Stewart recommended biting the tongue or inside of the mouth as well as using physical countermeasures such contracting a thigh muscle or shifting a toe that the operator cannot see.

The polygraph still has a high mistake rate due to inconclusive, false positive, or false negative readings, and it is susceptible to psychological and physical countermeasures.

Trickery in the Course of Control Questions:

Participants can regulate their respiration

The sphincter muscles contract.

biting one’s tongue or oral cavity

Imagining terrible things

In 2015, the federal government sentenced Doug Williams, a former polygraph examiner and Oklahoma City Detective Sergeant, to two years in prison for his activities related to teaching individuals how to beat the polygraph. He trained thousands of others to employ countermeasures when he began to doubt the technology’s performance after using it for years. He gives the polygraph’s accuracy a maximum rating of 50%. Indeed, as evidenced by the fact that U.S. government agencies have trained undercover agents how to ace the polygraph, Williams’ assertion that such procedures can be learned is supported.

Trickery When Asking Applicable Questions

Using relaxation methods

Making mental computations

Considering peaceful topics

The Benefits of the Polygraph

Notwithstanding its shortcomings, the polygraph opened the door for later advancements and established a new standard for the use of truth-verification technology in police interviews. The polygraph community boasts devoted users and a strong lobby. A considerable number of examiners who are trained to utilize this technology are hesitant to upgrade their knowledge or buy new equipment; yet, around thirty of the best polygraph studies indicate that this truth verification instrument is not as trustworthy as they would like to think. The accuracy of the polygraph has been measured in a variety of studies; estimates have ranged from 70 to 90 percent accurate. Furthermore, according to a 2003 National Research Council assessment by the Committee to Review the Scientific Evidence on the Polygraph, just 29% of 194 “scientific studies” cited as evidence by proponents of the polygraph fulfilled the minimal requirements of scientific sufficiency.

Nineteen states permit polygraph testimony under specific circumstances, and polygraph evidence has been successfully allowed in court. Both the public and business sectors have employed this technology for pre-employment screening. One of the main advantages of the polygraph test is its ability to get admissions from individuals who feel they have been exposed to deceit following an examination. However, in the Internet Age, those who are being tested using polygraphs may now receive information about the test that was previously unavailable or, in some situations, prohibited from being made public. These people have started to reverse the effects of the polygraph by realizing its numerous flaws, which are outlined on websites.