In 1921, John Augustus Larson, a medical student and police officer in Berkeley, California invented a machine to help detectives determine if someone was telling the truth - or lying. He called it - ...

Add Yahoo as a preferred source to see more of our stories on Google. American inventor John Larson, right, demonstrates the operation of a polygraph at Northwestern University in Evanston, Illinois, ...

The polygraph is not a lie detector but rather an instrument that measures a person’s physiological changes to questions posed by the examiner. An elevated physiological response to a particular ...