As soon I heard this Fresh Aire program on Dr. Paul Ekman (wiki, website, blog)--a researcher who decoded universal emotional reactions and teaches others to do the same--I had to buy the book, Emotions Revealed. Unfortunately, like many books that didn't immediately grab me, it collected dust.
Reading Blink by Malcolm Gladwell, I revisited Ekman's website and this time bought the basic facial recognition program. It takes about an hour to complete. (Background on Micro Expressions, 8 basic facial expressions which Ekman's software trains you to spot, TV program Lie to Me based on Ekman's research, Ekman research used with parenting, Ekman research used with law enforcement, On the Media.)
While it is thrilling to "read people's minds" as Gladwell puts it or to know whether someone is lying as the above websites put it less judiciously, I'm not sure that glimpsing these split-second emotions tell the whole story. Here's a personal example from my early post-high-school days:
My father made a comment to me, which aggravated me for a fraction of a second. I dismissed the emotion as quickly as it came because my father hadn't meant anything by it. So I forgot the emotion and responded in a normal, rational tone. However, my father replied in anger. I was puzzled: Why was he angry? As it so happened, the door was open at an angle that reflected my facial expression back at me. It still contained that earlier aggravation. It took me a moment to recall that flash of emotion that I had felt and dismissed. I felt no aggravation. If I had flashed aggravation and later denied it, would I be lying?
Could it be that the emotions we feel are our pre-packaged reactions, not true emotions (unless some people operate purely on pre-packaged emotions) taught to us by experience with our environment? These would help us cope with life using split-second reactions--reflexes or knee-jerk responses--much as one would remove his hand from a stove were it hot.
Perhaps Dr. Ekman responds to this in that dusty book of mine.