7 Psychological 'Tricks' That Are Total Bullsh*t

3. Lie Detector Tests

Put very simply, lie detector tests don't work. And even if they did, they would be very easily fooled.

Lie detectors, or polygraphs, measure things like heart rate, skin conductivity (sweating, basically) and breathing rate to sniff out a liar. The problem is that they make their measurements against a baseline control reading, which means that if you were highly motivated to lie, you could try to induce a stress response when answering the control questions, then the rest of your untruthful readings would match up.

You needn't bother, however, because they're so unreliable that the chances of catching a liar with a polygraph is little better than flipping a coin. It is for this reason that polygraph results are not admissible in a court of law, and so many people flip out at their lie detector results on Jeremy Kyle.