Political Parrhesia led us to this well-reasoned op-ed by Steve Chapman in Sunday's Chicago Tribune about the new report on polygraphs concluding that they are unreliable and shouldn't be used by employers. Chapman states that because polygraphs lie, they shouldn't be used in criminal investigations.

"The same fallibility that renders these machines unusable for employee monitoring makes them dangerous for criminal investigations as well. Police and prosecutors regard polygraph results as the closest thing to a dead-bang certainty. But that faith lacks any foundation. "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," concluded the panel."

"And there is no reason to think better technology will help. People simply don't respond in a clear and predictable way to questions about what they may have done wrong. 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," said the report. Polygraphs are a crude instrument that can't be refined."

"The consequences of a misleading polygraph exam are bad enough in the employment arena, where someone can lose a job or not be hired. But they're much worse for criminal suspects, who can be locked away or even put to death because their pulse rate rose too much in a stressful situation."