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The History Behind The Polygraph

Since humans first started communicating with one another and told lies, we have been telling them. We have also tried to discern the lies from the fact and this was increasingly important when societies developed legal systems. The law enforcement agencies and other organizations investigating crimes are aware that human ability to discern truth is limited, however we have the capability to develop technology that will identify signals that are not within our reach. Polygraphs were the initial invention to verify truth that demonstrated the ability of technology to identify deceit, but what is the status of this technology against the current situation?

This is the History Behind The Polygraph

The polygraph was referred to by the name of “lie detector” however, that is not accurate. There isn’t a scientifically proven method to identify the lies of a person, but there are methods of measuring psychological reactions triggered by stress from lying. This is the reason why this concept has led to the development of the polygraph and later, more advanced technologies for truth verification, like the computer-generated Voice Stress Analyzer (CVSA(r)).

The year was 1878. Italian physiological scientist Angelo Mosso examined the physiological responses of individuals when asked questions using an instrument called a plethysmograph to gauge cardiovascular and respiratory reactions. Many other scientists rediscovered his work and improved it.
An Canadian psychologist from Canada, John A. Larson invented a variation that was a polygraph when in the Berkeley (California) Police Department. The device was named by him “polygraph” after the Greek “polygraphos,” which is a reference to “much writing.” The device recorded and measured blood pressure and respiration as well as pulse. Leonarde Keeler further contributed to the device in 1938, by adding sensors that could measure the galvanic skin responses.
The polygraph model currently in use works much the same way as those that were developed close to 100 years ago. They measure the responses of sensors that are placed in the body. They include a blood pressure cuff that measures the heart rate and blood pressure and pneumograph tubes that measure respiration, and galvanometers tacked to the fingertips for measuring sweat.
In the 1940s, Chicago attorney John E. Reid further improved the polygraph procedure. Reid was the one to create The Reid Technique, an interview and interrogation method that is widely used by law enforcement agencies with and without polygraph test.
The modern polygraph is digital and, despite operating with the same principles with the same sensors and premise as an analog one that it utilizes an algorithm that evaluates the data and then display it in a computer software.

Polygraph Vulnerabilities

Chicago attorney William Scott Stewart wrote an article that was published inside the October 1941 edition of Esquire Magazine titled “How to defeat the Lies Detector.” It is most likely the first publication focused on countermeasures to the polygraph. Stewart noted that you could alter the results of the polygraph by increasing your reactions when you’re asked benign questions. The so-called “control question” are typically asked in the Control Question Test (CQT) and are intended to be a comparison to the pertinent questions. For physical countermeasures, Stewart advised biting the tongue or inside the mouth, or making movements that are not visible by the user like stretching a toe or moving an ankle muscle.

The polygraph is still susceptible to psychological and physical countermeasures, and is also afflicted by a substantial error rate that is based on inaccurate, false positives or false negatives.

Manipulation during Control Questions:

Subjects are able to manage their breathing
The contraction of the sphincter muscles
The tongue is biting or inside of the mouth
The thought of horrible things

A former polygraph examiner as well as Oklahoma City Detective Sergeant Doug Williams was sentenced to two-years in prison in the year 2015 for actions related to his efforts to teach people on how to defeat the polygraph. After many years of using the technology, he started to doubt the results and instructed thousands of people how to use techniques to defeat the polygraph. Williams rates its accuracy as 50 percent or more. In reality, U.S. government agencies have trained individuals who participate in undercover operations how to defeat the polygraph, which is a confirmation of Williams claims that strategies could be learned to beat the polygraph.

Manipulation During Relevant Questions

Practicing relaxation techniques
Mental calculations
I was thinking of subjects that can be calming.

The positive impact of the Polygraph

Despite its flaws polygraph established a new standard in the use of truth-verification technology in the police interview process . It also set the stage for new innovations in the future. The polygraph community is an influential lobby and many loyal customers. A lot of examiners who have been educated to utilize this technology are not willing to re-invent their abilities or invest in technology that is more modern however, approximately thirty percent of the most prestigious polygraph studies suggest that this truth-verification tool isn’t as reliable as people would think it is. The results of studies vary in assessing the precision of the polygraph with estimates that range between 70-90 percent accuracy. In addition just 29 percent from 194 “scientific studies” that were cited as evidence by those who advocate for the polygraph met the standards for scientific quality, as per The 2003 National Research Council report by the Committee to Review the Scientific Evidence regarding the Polygraph.

The evidence of polygraphs has been accepted in court. the states that allow it are 19 and that is based on specific conditions for every state. The technology is also employed for pre-employment screening in both the private and public sector. One of the main advantages to the use of the polygraph may be used to obtain confessions following examinations in cases where people believe that fraud has been discovered. However, in the modern Internet Age, individuals who are subjected to polygraph tests have access to information on the polygraph that was previously not accessible and, in certain instances it was not released to the public.

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