Lie Detection and Professional Ethics

This article from the BBC "The curious story of how the lie detector came to be" provides an interesting history of the device and some of its mythology:

The science behind the lie detector test has been disputed since its creation 90 years ago, so is there any reliable way to tell if someone is lying, asks Dr Geoff Bunn, author of The Truth Machine: A Social History of the Lie Detector.

"If I was guilty and wanted to beat that machine, it wouldn't be hard," says Sharon Stone's psychopathic character in Basic Instinct.
And the history of the polygraph - better known as the lie detector test - is littered with people who have been able to trick it.
The polygraph machine was invented in 1921 in Berkeley, California.
"Berkeley was a town with a very famous police chief, August Vollmer, and he was in charge of police reform and a leader of police professionalisation in the United States," says Ken Alder, professor of history at Northwestern University in Chicago.
"He actually wanted to use the science to make the cops more law-abiding themselves, to substitute this new scientific interrogation for what was formerly known as the third degree, which was a way of getting information from people by beating them up."

Find out more

The Truth And Nothing But The Truth is on Tuesday 21 May on 11:00 BST on BBC Radio 4 or catch it later on the BBC iPlayer.

• The Truth And Nothing But The Truth

Berkeley police officer John Larson created the first machine, basing it on the systolic blood pressure test pioneered by psychologist William Moulton Marston, who would later become a comic book writer and create Wonder Woman.

Marston believed blood pressure changes could show whether someone was lying.
The modern polygraph measures a range of physical changes such as pulse and breathing as well as blood-pressure.
But the credibility of the polygraph was challenged almost as soon as it was invented