A new study has claimed that polygraph test, popularly referred to as a lie detector, may not be a very useful tool to identify when a person is lying.
Lead author Chris Street from the University of Huddersfield said it has traditionally been said we should trust our hunches and unconscious knowledge of body language to detect whether someone is lying or not, but this study suggests people are better off consciously relying on a single cue to tell if someone's nose is growing, such as whether or not a person is plainly thinking hard.
To analyze how people lie to the most accurate extent possible, Street developed an experiment, in which participants being studied should not be aware that they are taking part in experiments that are dealing with the subject of truth and lies.
The researchers devised a deception of their own that involved hiring a film studio in London and persuading passers-by to be interviewed for a "documentary" on tourism.
The filmed interviews gave researchers a bank of material showing how people behave when they are lying. The material will be made available to other researchers in what is still a relatively new field of human lie detection.
Street and his co-researcher and author Daniel Richardson, of University College London, have developed a different explanation.
"Indirect lie detection does not access implicit knowledge, but simply focuses the perceiver on more useful cues," the researchers said. It is an argument that could have real-world significance, in the training of interrogators, for example.
The results are published in the Journal of Experimental Psychology: Applied