[AmericaUnited]

They don’t work on pathological liars. If the person truly believes the lie, the body does not change it’s response. Berger and the Clintoids are safe here.

[George Maschke]

They don’t work on pathological liars. If the person truly believes the lie, the body does not change it’s response. Berger and the Clintoids are safe here.

Polygraphs have not been proven to reliably operate at better than chance levels with normal persons under field conditions. And you don't have to somehow believe your own lies to pass a polygraph test when not telling the truth. Simple countermeasures that anyone can learn are readily available.