The defense department admits that the device is not perfect, but insists that it can help save American lives by screening local police officers, interpreters and allied forces for access to U.S. military bases, and by helping narrow the list of suspects after a roadside bombing.
However, the National Academy of Sciences has this to say about lie detectors:
"Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy... The inherent ambiguity of the physiological measures used in the polygraph suggest that further investments in improving polygraph technique and interpretation will bring only modest improvements in accuracy."
When asked specifically about the PCASS device, the lead author of the study, statistics professor Stephen E. Fienberg, stated:
"I don't understand how anybody could think that this is ready for deployment. Sending these instruments into the field in Iraq and Afghanistan without serious scientific assessment, and for use by untrained personnel, is a mockery of what we advocated in our report."
The first work on the idea of a lie detector was done by William Moulton Marston during WWI; he worked on a systolic blood-pressure test that could be used to detect deception.
He also created an illustrated version of a special handheld lie detector in a well-known fictional work; see a brief video of this device in action.
(The original handheld lie detector)
The Lasso of Truth (also called the Magic Lasso or Golden Lasso) forces a captured person to tell the truth in the Wonder Woman comic series.