People have been telling lies since the development of human consciousness. For as long as people have been telling lies, others have been trying to catch this behavior. Over the millennia, some people created systems they believed were effective at identifying deception in others.

The 1800s saw huge advancements in deception detection, with the 1900s witnessing the introduction of the first “polygraph,” an electronic system for detecting lies in statements. The polygraph as we know it today results from a progressive technological evolution pursued by experts in the field.

It results from centuries of development and tuning into a machine that looks nothing like the first iterations from the 1800s. In fact, you can be sure the original inventors of the first lie detector tech would be shocked to see its current format.

What began with a handful of rice shows us that the modern polygraph displays the work and dedication of an entire civilization. Determining the truth is a cornerstone of developing trust. Whether in personal or professional relationships – the truth forms the foundation of the social contract.

The polygraph is a vital technology used to detect deception in various circumstances. It’s undergone some significant changes to get to where it is today. This post unpacks a brief history of the lie detector test and how the tech evolved from humble beginnings.

Timeline of Polygraph History

  • 1921: John Larson, a police officer and medical student, develops the first polygraph instrument, combining measurements of blood pressure, heart rate, and respiration.
  • 1930s: Leonard Keeler, referred to as the “father of polygraph,” improves upon Larson’s design by adding skin conductivity.
  • 1947: The CIA begins using the polygraph for security screenings and intelligence operations.
  • 1950s: The polygraph gains popularity as a tool for law enforcement agencies in the U.S. for criminal investigations.
  • 1960s: Polygraph testing becomes more standardized with established protocols and training programs.
  • 1974: The Employee Polygraph Protection Act is passed, restricting the use of polygraphs in the workplace and setting standards for their use.
  • 1988: The American Polygraph Association (APA) establishes a code of ethics and standards for polygraph examiners.
  • 1990s to present: Advances in technology improve polygraph accuracy and reliability. New techniques and models are developed, integrating computerized systems.
  • 2000s: Ongoing research about the validity and reliability of polygraph tests influence regulations and practices worldwide.



The Early Beginnings of Deception Assessment – Rice & Warriors

The first methods of detecting deception and dishonesty in people extend back to ancient China. The Chinese were the first to realize a connection between lying and physiological stress. They realized lying resulted in a person’s mouth drying out due to a drop-off in saliva production.

So, people would ask a person to chew on a handful of rice when answering questions about their honesty and behavior. If the rice came out of the person’s mouth dry, they were considered liars. Detecting deception and dishonesty has always been an important part of society.

The warriors of Sparta would use methods to determine those warriors with fearless characters and those who were cowards. They would take prospective warriors to the edge of a cliff and ask them if the height and risk of falling scared them.

The answer was always no, but the warrior developed a keen sense of determining the fear in the person’s voice as they stood staring at potential death. If the master warriors detected any fear in the apprentice’s voice, they would push them off the cliff to their end. The Spartans did not value cowardice.

In the times of the Spanish Inquisition, we saw the most brutal examples of flushing the truth from deceptive individuals. These dark times in the Catholic Church formed the modern foundation for determining dishonest and truthful behavior in interrogated individuals.

They were the first to realize and analyze the role of blood flow in deceptive behavior. The interrogators would monitor a person’s pulse rate when questioning them. The practice resulted in the conclusion that a person’s pulse rate would rise when they were lying during the interrogation.

They didn’t realize it at the time, but this simple observation would form the foundation of what would later become the first lie detector device.


Angelo Mosso – Where It All Starts

While methods in lie detection progressed over the centuries since the Inquisition, it was in the late 1800s that we saw the appearance of the first lie detector methodology. In 1875, Italian physiologist, Angelo Mosso, started his research into how the fear response related to lying behavior.

Mosso was determined to prove measuring physiological changes in a subject’s body would lead to the detection of deception and the possibility of the invention of the first polygraph technology. Mosso knew the age-old revelation of the connection between pulse rate and lying.

However, he discovered other factors influencing the sympathetic and autonomic nervous system, such as increased blood pressure and respiratory rate playing a role in deceptive behavior. His research led him to develop a series of devices known as “plethysmographs.”

These devices would measure changes in blood pressure or breathing, giving Mosso the first scientific method of determining deceptive behavior in individuals questioned about their honesty. The idea for the machines was built around simple methodologies.

If the subjects breathing or blood pressure changed during questioning, the conclusion was they were being deceptive in their answers. This fear response forms the base of the modern lie detector. We can’t control the body’s “fight-or-flight” response; it’s governed by the sympathetic nervous system and automatic response to external stimuli.

So, Mosso determined there was a definitive connection between telling lies and changes in the stress and fear response created by the sympathetic nervous system. As a result, these changes concluded that the person under questioning made false statements. Now, there was an actual machine capable of determining this behavior – and no further need to throw people off cliffs.


Dr. Marie Vigouroux – Developing Electrodermal Response

Mosso’s initial success in the polygraph field paved the way for the progression of this technology. The next individual to pick up the torch was the French therapist, Dr. Marie Gabriel Romain Vigouroux. He was the first to identify the “electrodermal response” involved with deceptive behavior.

In 1879, Vigouroux formulated the idea that deceptive individuals would experience a measurable change in the electrical resistance of the epidermis. Dr. Vigoroux published an account of his research in 1879, with several other leading minds in the field furthering the discovery to make new revelations.

Harvard psychology professor, Boris Sidis, performed a series of experiments titled “A Study of Galvanic Deflections Due to Psycho-Physiological Phenomena.” His research showed a relationship between alterations in emotional states and galvanic changes in the skin. The professor presented his findings to the American Psychological Association in 1909.


Cesare Lombroso – The First Appearance of Deception Identification in Court

While Sidis was busy with his research, 1895 saw Italian criminologist Cesare Lombroso conduct tests using a device for measuring pulse rate and blood pressure to detect deception. Lombroso monitored individuals for blood pressure changes after asking questions about their behavior and actions.

He named his device the “Hydrosphygmograph.” Lombroso published studies showing using a sphygmomanometer and plethysmograph when interrogating suspected criminals. The experiments had surprising accuracy.

In 1902, seven years after Lombardo presented his work, the first device was used in court to prove a man’s innocence. Slowly, the modern polygraph was beginning the take shape.


Vittorio Benussi – Breathing Changes Everything

The real breakthrough in polygraph technology came from Italian Vittorio Benussi in 1914. He was the first to introduce the impact of respiratory rate into lie detector tests. Benussi announced he could determine if a person was lying by analyzing their breathing.

To prove his theory, Benussi designed his “pneumography.” This instrument measured the respiratory rate in the interrogated individual. He based his work on the “I/E ratio” or “Inspiration/Expiration ratio.” His research showed dividing the length of inhalation by the length of exhalation showed an increase in the I/E ratio when the person was lying.


John Augustus Larson – The Originator of the Modern Lie Detector Machine

In 1921, John Augustus Larson, an American medical student, invented the first “lie detector” machine. The device could measure several physiological responses simultaneously, focusing on the subject’s pulse, blood pressure, and respiration rate.

The doctor built the device to assist law enforcement in investigating criminal cases. The world’s first polygraph was an effective device, contributing to convictions in many criminal cases. With the groundwork created for the first polygraph device, others took up the mantle of refining the performance and accuracy of the machine.

However, Larson did not build his device based on his proprietary knowledge. Instead, he refined a previously known procedure invented by lawyer, psychologist, and inventor William Moulton Marston. Marston outlined a scientific method of interrogation used in World War I.

Larson worked with this concept, evolving it into his unique device, which he presented to the Berkeley Police Department in 1921. Larson’s technique, known as “the R/I (relevant/irrelevant) procedure,” involved asking the suspect a mixed bag of questions.

Some would be relevant to the case, while others would be irrelevant. This methodology provided outstanding results in polygraph testing, with surprising accuracy that stunned those involved in the examinations.

This breakthrough technology was so vital in changing law enforcement and lie detection results that it was placed on the “Encyclopaedia Britannia Almanac 2003 list of 325 Greatest Inventions.” Larson continued his work on the polygraph after dying of a heart attack in 1965 at 72 years old.

While Larson did not develop any new features to his device, he paved the way for the modern polygraph systems we know today. He also played an instrumental role in changing the criminal investigation process and improving the conviction rates of serious offenders.


Leonard Keeler – Progressing the Technology

John Larson’s college Leonard Keeler took up the task of improving Larson’s device. The pair worked together at the Berkley Police Department, where Keeler would specialize in statement verification in polygraph interviews.

In 1925, Keeler designed and built a new version of Larson’s polygraph using specialized ink pens. These pens provided visual readouts of the physiological responses measured by the polygraph in questioning procedures.

This innovation improved the observation of the subject’s blood pressure and respiration rate, improving the accuracy of the examinations. Keeler kept developing the technology. In 1938, he added a feature to the device measuring the skin’s electrical resistance, similar to the work by Dr. Vigoroux in the late 1800s.

This invention was labeled the “psycho galvanometer.” After producing the first device, including all his innovations, the machine was dubbed the “Keeler Polygraph.” It was the machine closest to the modern polygraph we use today and the foundation for the contemporary evolution of polygraph technology.

While we could call John Larson “The Father of the Polygraph,” Keeler is “The Father of the Modern Polygraph.” Keeler continued his research in the field he revolutionized, adding enhancements and improvements to the questioning and interviewing techniques used in the polygraph exam process.

The results provided by his device were nothing short of astounding to law enforcement and justice officials. He received a patent for the Keeler Polygraph in 1931, and it would dominate the industry f the next three decades.

By 1935, Keeler had examined more than 2,000 suspects in various cases. During his career, he processed more than 30,000 examinations on suspected criminals, and in 1947, he founded the “Keeler Polygraph Institute” in Chicago, the world’s first polygraph school. Sadly, he passed away in 1948.


John E. Reid – Providing the Breakthrough in Modern Polygraph Technology

While the modern polygraph was a tremendous device capable of detecting lies with incredible accuracy, the next evolution in lie detector technology would come from the questioning side of the examination process.

The next individual to advance polygraph technology was John E. Reid. A Chicago-based lawyer, Reid developed the “Control Question Technique” between 1945 and 1947. This process involved asking the suspect control questions to compare to the real investigative work in the examination.

Individuals found telling the truth in the examination questioning process would illicit a stronger physiological response to irrelevant questions to which they were lying. John E. Reid also gained his reputation in the polygraph sciences for developing the “Reid technique” used in interrogations.

The method caused controversy lasting until today due to the proven fact that it can occasionally produce false readings. Despite the controversy, there’s no question that the “CQT” (Control Question Technique) dramatically improved the results of polygraph examinations, providing new possibilities for improving the accuracy of polygraph testing.

John E. Reid also contributed to the advancement of the tech side of the polygraph examination process by introducing motion sensors to the device. These sensors monitored the examinee’s muscle movements during the interrogation. If the pads detected abnormal activity in the muscular system of the examinee, it was a sign of deception.

Cleve Backster made the final improvement of polygraph devices and examination methodologies in this era. Backster was a CIA polygraph examiner responsible for introducing the “quantified chart analysis technique.”

This innovation dramatically improved the efficacy and accuracy of the polygraph examination results. The method utilized numerical analysis and formed the basis for today’s modern technology involving complex algorithms and software solutions.

The 1950s also saw the founding of the Lafayette Instrument Company, the first company to focus on designing, developing, and producing polygraph devices and related technologies. Max Wastl founded the company in 1947, shifting to focus exclusively on polygraph technology in the 1950s.

Lafayette is now the biggest and most respected name in polygraph development and production. It has a solid reputation for producing equipment trusted by leading polygraph examiners around the globe.


The Computerization of the Polygraph – A New Era

After the 1950s, the use of polygraph technology spread across the world, infiltrating law enforcement and justice departments in every country. The device was widely used in the United States before the 1960s, with tens of thousands of polygraph exams issued yearly.

While it was an effective technology in the 1950s, the introduction of the digital era and the invention of the computer changed everything. The 1980s saw scientists at the University of Utah invent the “Computer Assisted Polygraph System” (CAPS).

This shift in polygraph analysis gave way to the modern era of polygraph science, where a computer is solely responsible for analyzing data produced during lie detector examinations. The development of algorithms took the place of human interpretations, reducing the occurrence of human error in the exam and analysis phase of polygraph testing.

1992 saw the breakthrough into the modern era of digitized polygraph science. The field experienced rapid developments in instrumentation, devices, and software used in the exam process. As computers became more powerful and algorithmic technology progressed in complexity, scientists developed several innovations in the polygraph space.

Emphasis turned to improve accuracy in measuring physiological responses to questioning, assessed by electronic devices, and governed by algorithmic processes. It was only a short time before polygraph companies released the first dedicated software packages for polygraph processes.

The Lafayette Instrument Company also played a huge role in developing this technology, creating the benchmark standard for polygraph devices and software trusted by polygraph technicians and examiners worldwide.

In 2007, Lafayette was the first organization to introduce a wireless polygraph device. The company released the LX4000-SW, one of the most-used models in the modern era of polygraph examinations.



The Evolution of Technology – The Modern Polygraph

Today, the polygraph is a trusted method of verifying truthful statements. There are hundreds of agencies and associations using polygraphs to identify deceptive behavior. While the corporate world continues to see an ever-increasing need for polygraph technology, it’s also spreading significantly into the private sector.

Polygraphing services will continue to see an ever-increasing demand in the public and private sectors. Despite the accuracy of these devices and software, there’s still plenty of controversy surrounding the use of polygraphs. So much so that using them as a pre-employment screening tool is outlawed in many countries, including the U.S.

Polygraph results are now admissible in court. However, they are not considered standalone evidence. For a polygraph to be admissible, it must corroborate other admissible evidence and assist the court in achieving a verdict.

The controversy surrounding polygraph examinations stems from the accuracy of the results provided. Those professionals involved in polygraph technology and other proponents insist it has a 98% accuracy in detecting deception.

The other side of the argument shows accuracy only in the range of 60% to 70%. So, while there is substantial evidence confirming the efficacy and accuracy of polygraph testing, it remains unapproved for use as a standalone factor in determining guilt or innocence in court and other legal matters.

The reality is the polygraph has come a long way from a handful of rice shoved into a person’s mouth thousands of years ago. It shows tremendous utility for uncovering deception and continues its dominance as the benchmark in truth detection worldwide.

Polygraph Technology in the 1990s Vs the 2020s

Explore the evolution of polygraph technology from the 1990s to the 2020s in this comprehensive article. Dive into the advancements, challenges, and implications of lie detection over the decades, from the era of analog devices to the sophisticated digital systems of today.

Uncover the Truth with a Professional Lie Detector Test – Our Carefully Vetted Examiners Ensure Your Peace of Mind.