Can lie detector devices be trusted 100%?
No. Lie detection devices rely on reading various body signals (sweaty-palms, racing heartbeat) that happen when you lie. And these signals can be wrong for a lot of reasons. First off, if you don’t think that you are lying, then there is no “lie” to detect. The machines can not tap into some huge library of truth. They only measure the human body. So if you’re not lying but wrong, the machine won’t know. Second, some people don’t give off these signals when they are lying. They’ve either trained themselves not to, or they are sociopaths, or whatever. No physical cues, nothing for the detector to pick up. And flawed answers. Third, some people give off these signals whether or not they are lying. This is one way people learn how to beat these tests. If your heart races on every question – true or false – then there is no way to determine when your heart is racing because you were digging your fingernails into your palms and when your heart is racing cuz you’re lying. Sorry. They just a
