Are these tests meant to be pretty accurate? And has anyone done them or known someone who has done one?
Most Helpful Girl
Well, back in the day I used to be super interested in detectives and from memory I think that lie detectors detect your heartbeat, sweat and blood pressure etc (Generally things that are quite high for someone who is lying) However accurate these are depends on the quality of the machine and the way a person is under pressure. For example, someone who is still telling the truth could be under pressure from being on the spot and naturally begin to sweat and have an increased heart rate. Equally there are some people who can lie very easily without worrying etc.
So while lie detector tests are deemed pretty accurate, they're not always right.
(Just in case my knowledge from when I was 10 is a little rusty, this site seems pretty good to read up on: http://people.howstuffworks.com/lie-detector1.htm )1
Most Helpful Guy
They are pretty accurate. The American CIA did do a series of experiments on ways to beat them, and found that their are ways to beat it, but only with training and experience. You can assume that the results will be accurate. If you are in the US and you are taking one for legal reasons, don't, as the results can not be used in a court of law. So if you pass they can still charge you and the fact that you passed you can't use in your defense, and if you fail then they'll slip it in to the record. At least speak to your attorney first.0