It is complete pseudoscience. In the Penn and Teller's BS episode about it they have a guy who teaches people how to get whatever result they want by controlling their anal sphincter. Apparently it's not complicated.
It is, however, still a part of getting or maintaining clearance. A friend of mine wound up changing jobs simply because he failed the polygraph twice and didn't want to bother going in for a third.
It is, however, still a part of getting or maintaining clearance. A friend of mine wound up changing jobs simply because he failed the polygraph twice and didn't want to bother going in for a third.