Polygraphs, or lie detectors, are frequent shown on TV as an accurate way of detecting lies. So what's the truth? According to the research polygraphs have a high false positive rate, meaning that the test isn't measuring a person's lie rather the anxiety of potentially being convicted of a crime that they may or may not have committed. Polygraph test also have a high rate of being able to "fool" through simple techniques that are designed to throw off the baseline readings. Those with emotional disturbances, whom don't feel a strong sense of guilt, are also quite easily able fool the polygraph and "pass the test". Other methods such as Guilt Knowledge Test and fMRI imaging, which have proven to produce less false positives than polygraphs are only effective if the person that committed the crime remembers minute details of the crime scene. So this leads to an interesting question. Do lie detectors continue to be effective in modern day because people are not aware of how inaccurate they really are? In fact due to these significant flaws in the tests, lie detector tests are only admissible in court on a state-by-state basis. Though many states are in the process of changing the admissibility in courts. As a result there are many appeals that are trying to get the polygraph evidence thrown out.
Click here for more information on polygraphs: American Polygraph Association