your answer is naive----there are PATTERNS on the polygraph (DA WAVES) that correspond
STATISTICALLY to what happens when a person lies at the SKIN.
What statistics are those?
What happens on a polygraph when someone is deceptive? Does the chart spike up?
Can it spike down?
Can it do nothing at all? Can someone who's telling the truth be measured as being deceptive?
Please, regale us with your intimate knowledge of polygraph tests.
One of the main reasons polygraphs aren't admissible, aside from the reasons I've already laid out, is that they are simply inaccurate up to 15% of the time, and there are plenty of examples where the polygraph failed to do what was hoped.
Oh, I worked for NIS (Naval Investigative Service) for five years while on active duty and was present for more than a few of these...