polygraph -- not a science

Different federal agencies administer their own polygraph tests for security clearances, and come up with different conclusions for the same people. Further proof that polygraphs are BS. Even an expert polygraph administrator and proponent admits 'that interpreting polygraphs is more "art than science" and that examiners at different agencies range from "Rembrandts" to "finger-painters."'

He also said that after the Aldrich Ames scandal (remember him? A drunk CIA agent who gave Russians secrets, and passed several polygraphs?) the CIA testers have to browbeat people and brag now about how they "catch" people that other testers don't. I'll bet a lot of those "catches" are false positives.