#2 Breathing
Image Source: Robert Anthony Provost
This behavior is not quite as easy to pick up on as head movement, so you may have to practice a bit to get good at spotting this signal. Someone who is telling a lie will often begin to breathe a bit heavier. You may be able to pick up on this by observing other changes that are triggered by their breathing. They may raise their shoulders slightly, and the sound of their voice may become a bit more shallow. Changes in breathing are triggered by the nervousness and tension that a person experiences when they tell a lie – even if they are not aware of it themselves.
