Science correspondent Ronald Bailey reports for Reason magazine on fMRI-based “lie detection” in “Reading Minds: Is Commercial Lie Detection Set to Go?” Excerpt:
Evolutionary psychologists suggest that human cooperation is the result of evolved brain mechanisms that enabled our ancestors to detect cheaters. Broadly speaking, cheaters are people who accept a benefit from someone on the understanding that they will reciprocate, but then fail to give back. A robust finding of game theorists is that the ability to detect cheaters is necessary for cooperation evolved. In the constrained situations that characterize games it’s easy for players to detect cheaters because their lack of reciprocation becomes immediately obvious. But what about the real world? Are evolutionary psychologists right when they claim that human beings have evolved into natural lie detectors?
Most of us think that we’re pretty good at identifying liars. However, a lot of experimental data says that we’re wrong. Most people can distinguish truth from lies at a rate no better than chance. Not even professionals, such as cops and judges, do much better. Of course, humanity has been ceaselessly seeking the fool-proof lie detector, ranging from thumbscrews to polygraph testing. With regard to the latter, the National Academies of Science issued a comprehensive report in 2003 on polygraphy that concluded, “There is essentially no evidence on the incremental validity of polygraph testing, that is, its ability to add predictive value to that which can be achieved by other methods.”