> [!quote] [The psuedoscience of lie detectors](https://www.science20.com/gerhard_adam/pseudoscience_lie_detectors-93551) > However, lie detection, or polygraphy is not based on science. In fact it isn't based on much of anything, except psychological manipulation of the subject under the guise that taking the lie detector may cause them to confess, because they believe it is based on science. > > In short ... it's voodoo psychology. > > The first problem is in what the polygraph, or lie detector actually measures. The lie detector measures blood pressure, heart rate, respiration, and galvanic skin response or skin conductivity. Therefore the first scientific problem that must be addressed is what the correlation with these physiological measurements has to do with deception. It seems clear that the objective is to measure anxiety, but this presupposes that individuals become anxious for the same reasons and under the same circumstances. Since there is no context for these measurements by themselves, the thinking is that by asking some control questions, a kind of baseline can be established against which deception can be measured. > > However, the problem with that, is that it presumes that individuals react in a predictable manner with specific traits associated with deception. In other words, the underlying "theory" is that physiological reactions will occur because of "guilty knowledge" in whatever is being investigated. - [I] This is a useful #storystem/fic because when I write about mentalist and psychic type characters, I should do it with the seriousness and earnestness that modern culture treats lie detector techs.