A handheld lie detector is to be given to US Army soldiers in Afghanistan this month. The device, called Preliminary Credibility Assessment Screening System (PCASS), will flash red when the subject varies from what he believes to be the truth.

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 (see demonstration photo), 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."

Lie detectors have an interesting history. 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 a special handheld lie detector in a well-known fictional work (see actress Lynda Carter demonstrate the device in this brief video).

You may have guessed it: Marston is the creator of the Wonder Woman comic character. The Lasso of Truth (also called the Magic Lasso or Golden Lasso) forces a captured person to tell the truth in the comic (and the television show).

(This Science Fiction in the News story used with permission of Technovelgy.com.)