HOW do you tell if someone is lying? Easy, according to many of those who should know the answer, such as US government law enforcement and intelligent agencies: hook them up to a polygraph lie detector.
The FBI regularly uses the polygraph in national security investigations, and evidence from it is even admissible in some civilian courts in the US. Now the British government seems to share this optimism about the polygraph’s truth-divining capabilities: last week it revealed it is considering making it mandatory for testing sex offenders.
The trouble is, the polygraph doesn’t work – at least, not in…
