The History of Lie Detector Machine


In a world where truth is of utmost importance, the quest to detect deception has led to the development of lie detector machines. Among these machines, the first lie detector, known as the polygraph, holds a significant place in history. In this blog, we will delve into the fascinating journey of the first lie detector machine, from the initial idea conceived by William Moulton Marston to the advancements made by Dr. John A. Larson and Dr. Leonard Keeler.

The Era of Polygraphy

William Moulton Marston and the Invention of the Polygraph:

William Moulton Marston, a renowned psychologist and creator of the fictional character Wonder Woman, was intrigued by the idea of detecting deception through physiological responses. Drawing inspiration from his work on emotions and human behavior, Marston conceived the concept of a lie detector machine. He believed that changes in blood pressure and pulse could indicate when someone was lying or being deceptive.

Dr. John A. Larson: Creator of the World’s First Polygraph:

While Marston planted the seed, it was Dr. John A. Larson who brought the first polygraph machine to life in the early 1920s. Larson, a police officer and medical student at the University of California, Berkeley, collaborated with Marston to develop the machine. Larson’s invention recorded changes in blood pressure and pulse, utilizing an inflatable cuff placed around the suspect’s arm. These physiological responses were believed to be indicators of deception.

Dr. Leonard Keeler: Advancing the Polygraph:

Dr. Leonard Keeler played a pivotal role in refining the polygraph machine. Keeler, an associate professor of psychology at Northwestern University, recognized the potential limitations of the original design and sought to improve it. He added an additional element to the machine by including a galvanic skin response measurement, which examined the electrical changes in the skin. This improvement allowed for a more comprehensive assessment of physiological responses, enhancing the accuracy of the lie detection process.

The Legacy of the First Lie Detector Machine:

Early Applications and Criticisms:

The first polygraph machine found its early applications in criminal investigations, where it was used to assist in questioning suspects. However, skepticism arose regarding the reliability and accuracy of the machine’s results. Critics argued that physiological responses could be influenced by factors other than deception, such as anxiety or stress. These concerns prompted further research and refinement of lie detection technology.

Evolution and Advancements:

Despite the initial criticisms, lie detection technology continued to evolve. Over time, advancements such as the inclusion of respiration rate and the development of computerized algorithms for data analysis contributed to the enhanced accuracy and reliability of lie detectors. The introduction of additional measurements, such as eye movement tracking and voice stress analysis, further expanded the capabilities of modern polygraph machines.

Ethical and Legal Implications

The Use of Lie Detectors in Criminal Investigations:

Lie detectors have been used in various criminal investigations, but their admissibility as evidence in courtrooms has been a subject of debate. The reliability and potential for false positives or negatives have raised ethical concerns and legal challenges regarding their use. In many jurisdictions, polygraph results are not admissible as standalone evidence but may be used to support other forms of evidence.

Lie Detection in Other Fields:

Beyond criminal justice, lie detectors have found applications in employment screenings, national security assessments, and other fields where truth verification is crucial. However, issues such as privacy, potential biases, and the human rights of individuals have emerged as important considerations when employing lie detection technology. The field is constantly evolving, with researchers exploring alternative approaches, such as neuroimaging and voice analysis, to enhance accuracy and address ethical concerns.


The first lie detector machine, born from the idea of William Moulton Marston and realized by Dr. John A. Larson, revolutionized the pursuit of truth. Dr. Leonard Keeler further advanced the polygraph, shaping its modern form. While lie detectors have made significant progress in accuracy and technology, debates persist regarding their reliability, ethical implications, and use in various fields. 


As society progresses, alternative approaches and emerging technologies continue to redefine the boundaries of truth detection in the quest for justice and honesty. While the journey of the first lie detector machine may have begun a century ago, the exploration of deception detection methods remains an ongoing endeavor, driven by the desire to unravel the mysteries of human behavior and unlock the truth.