A broken promise is not a lie.
Most liars can fool most people most of the time.
Emotions Revealed: Recognizing Faces And Feelings To Improve Communication And Emotional Life.
MOST LIES succeed because no one goes through the work to figure out how to catch them.
People also smile when they are miserable.
The distinction between shame and guilt is very important, since these two emotions may tear a person in opposite directions. The wish to relieve guilt may motivate a confession, but the wish to avoid the humiliation of shame may prevent it.