Sounds like most of this focuses on the spoken word, correct: That's where the truth always hides. 'Body language' is the buzzword of the deception industry, but it's (almost) total bunk. There's nothing that will reveal more than your being able to listen well and know what to listen FOR.

People tell more than they realize, the only thing that saves them is virtually NOBODY knows how to 'listen between the lines.' It's not hard, but you do need to know a few tricks.