[wedog6]

I believe it was the subject of the test who could make the polygraph reading show whatever they wanted, even though it was being administered by an experienced operator.

[the_af]

I think the point is that, since polygraph readings are pseudoscience, it's always the interrogator who picks what they "mean". If this is true, a smart test subject cannot mislead them, since there's nothing to mislead, as the polygraph is just a pressure technique and it means whatever the interrogator needs it to mean.