When I read this, I immediately thought of my favorite pop-culture lie detector reference: https://www.youtube.com/watch?v=ylthSc5tcqk
Still hilarious 23 (?) years later, but the laughs are based on the assumption that the device really works that well.
Because for the better part of a century, the entertainment industry (and Hollywood in particular) has told us they work. They're a central plot device in tens of thousands of books, radio dramas, plays, television shows, and movies.
It's like they say in politics: If you tell a lie enough times, it becomes the truth.