Glad to see James Randi’s unequivocal denunciation of the (so-called) “lie detector” (“A Consistently Erroneous Technology,” September/October 2017). From a detailed study of its history, I think there might have been a period when the technique had some (small) value. Not because it can actually detect lies but because of its intimidation factor. Before everybody became inundated in technology, a skilled interrogator, aided by the polygraph mumbo-jumbo, could “sweat” admissions out of suspects without the use of physical abuse. That was certainly the intent of Chief Gus Vollmer (Berkeley, California) when he encouraged Dr. John Larson to build the device in 1921. Larson had a PhD in physiology and is generally credited with the invention of the first practical polygraph, which combined readings of blood pressure, pulse rate, respiration, and skin conductivity (related to sweat production). He later attained a medical degree in clinical psychiatry.
By the 1930s, Larson had essentially launched a crusade against the improper use of the device. Speaking in Detroit, Larson told an interviewer, “It is essential to realize that this testing does not detect lies, but [rather] painful complexes which are intensified by focusing the suspect’s attention on questions of truth or falsehood.” He saw it as a useful tool for psychiatry, but just that … and he strongly opposed any move to use the results in court.