The documentary tells a story of honest intentions and sinister consequences. John Larson, one of its inventors, was a medical student and law enforcement officer in search of more humane methods of policing and interrogation. He piggybacked off new scientific and psychological concepts to create the device in 1921.
The technologies Larson and his co-inventors used were still in their infancy, and the idea that people produce measurable, consistent physical symptoms when they lie was unproved.
It still is. Polygraph protocols have evolved, but the devices’ detractors say they measure only anxiety, not truthfulness. And even as major organizations have raised questions about the scientific validity of the tests and federal laws have prohibited most private employers from requiring them, the idea that dishonesty can be measured through physical testing remains widespread.
The documentary suggests that the polygraph tests’ popularity was tied more to publicity than accuracy — and over time, Larson’s vision was turned on its head as polygraphs were used to intimidate, incarcerate and interrogate people.
With the help of expert interviews and a kaleidoscope of historical footage and imagery, director Rob Rapley tracks the tale of an invention its own creator compared to Frankenstein’s monster.
It’s a challenging, eye-opening view of the potential consequences of society’s desire to fuse psychology and science, and a cautionary tale that says as much about the psychology of the concept’s proponents as those whose truthfulness they question.