06/12/1921 • 4 views
First modern lie detector test administered using a polygraph in 1921
On June 12, 1921, physiologist John A. Larson conducted what is widely considered the first modern polygraph test in Berkeley, California, using instruments to record respiration, blood pressure and pulse as indicators of deception.
Larson had trained in physiology and advocated for objective, instrument-based methods in criminal investigation. His device—sometimes called a cardiograph or polygraph—used a pneumograph for respiration and a manometer and other apparatus to register changes in cardiovascular activity on moving paper. The goal was to produce a continuous record that could be compared across control and relevant questions in an effort to detect patterns associated with lying.
The 1921 application built on earlier efforts by researchers who had explored physiological responses to stress and deception, but Larson’s approach emphasized practical use in police work and systematic recording. After the Berkeley test, variations of the polygraph spread to other law-enforcement agencies and forensic practitioners in the United States and abroad. Larson published descriptions of his methods and later refinements, and his work contributed to the popularization of the term “polygraph,” meaning ‘‘many measures.’’
Despite early enthusiasm, the scientific status of the polygraph has remained contested. Critics point to variability in physiological responses across individuals, the influence of anxiety and other emotions unrelated to deception, and the lack of a definitive physiological marker that uniquely signals lying. Over ensuing decades, courts, researchers and law-enforcement agencies have debated the admissibility and reliability of polygraph results. Some jurisdictions allow polygraph evidence under narrow circumstances, while others reject it or limit its use to investigative or screening contexts.
Historically, Larson’s 1921 test is significant not because it solved the problem of detecting lies but because it institutionalized an approach that combined physiological measurement with forensic investigation. It marks a transition from anecdotal and interrogation-based methods toward instrumented, ostensibly objective techniques. The method’s adoption influenced criminal procedure, employment screening, and popular culture, even as scientific and legal scrutiny persisted.
Contemporary research has produced mixed conclusions: some studies report above-chance accuracy for detecting deception under certain protocols, while meta-analyses emphasize error rates and the potential for false positives and negatives. Consequently, the polygraph remains a tool used in specific investigative roles rather than a universally accepted forensic standard. Recognizing both its historical impact and its scientific controversies provides a balanced view of the legacy of the June 12, 1921 test.