Many parallels between the history of the polygraph and black-box chain analysis
Discussion
It's a bluff?
Lots of money to be made by operators and a huge lobby to defend dubious reliability of the technique
Ooh, interesting. I know very little about polygraphs but remember hearing they were largely a way to get confessions. Probably oversimplification, and like you allude to, could see how an interested party could benefit from the unreliability.