A paper published in 1921 by a psychologist and lawyer called William Moulton Marston described an experiment in which he claimed to be able to detect whether someone was telling the truth based on blood pressure readings alone.
Marston discovered that he could tell, based on blood pressure readings alone, which of his peers were lying. The idea that the actions of the body could betray the mind has been around for centuries. The general impression that Marston left his superiors with was that the results had more to do with him as an individual than any scientific breakthrough he’d made. Gus Vollmer, who was lost in thought at his desk at police headquarters, read Marston’s latest article with growing interest. Vollmer thought that if blood pressure rises during lying, it could be registered on a machine. Vollmer handed John Larson, a police officer, a book by Cesare Lombroso, the Italian criminologist, and the journal with Marston’s article in it. Larson’s assignment was to research and develop a machine that could accurately measure blood pressure in criminal suspects during questioning.
Source: https://crimereads.com/invention-polygraph-lie-detector/?ref=the-browser
