Our topic today: Faces, Feelings, and Lies.  And, in particular, how can we know what a person is feeling by looking at their face, and in particular can we know if they are lying?  There is clearly both a psychological side to this and an epistemological side.  Our guest is famous for his work on the psychological side, with a positive result:  we can know what a person is feeling, and whether they are lying; at least the information is often there in the face.  But it’s not always so easy. 

Ken and I will also be interested too in the epistemological side; what is the relation between the evidence we can see and the conclusions we draw?   We can start with the conclusions.  To what extent are feelings and emotioins, including the sincerety with which one says something, hidden?

By feelings we  mean not only the inner experience we have in certain situations.  But these feelings --- or better,  `emotions ‘ seem to also have a cognitive element.   If we're angry, we're angry about something.  If you carelessly spill coffee on me, I would have a feeling of anger.  But it would be anger at you, for spilling the coffee, or for being careless.    The emotion seems to be a complex, involving a feeling and a belief that gives rise to it and sustains it.  Sometimes we feel anger, but don’t know what we're angry about.  That’s not terribly uncommon, but it is odd.  We're perplexed until we figure out what we're angry about.

Indeed,  David Hume, the philosopher, thought the very same inner feeling could be connected with different emotions, where the cognitive factor was the differentiating element.  When Ken finishes his book on norms, I’m sure he’ll be proud of it. The cause of the pride will be the perceived high quality of the book.  The object of pride will be Ken himself.  The feeling is pleasure.  Now consider the esteem Ken feels for me.  The cause is my intelligence and wit.  I am the object.  But the feeling is basically the same, pleasure.

What about the anger I had for you, when you carelessly spilled coffee on me?  Well, the cause is my spilling coffee, the object is me, and the feeling is displeasure.  If you spilled the coffee on yourself, that would be the cause, the object would be you, i.e., self.  The feeling would also be displeasure, and that combination of things we call humiliation, not anger.

 Hume is no doubt not the last word on emotions.  I think our guest, Paul Ekman, will tell us that modern techniques of experimentation make it pretty clear that the same feelings are not involved in different emotions, in the way Hume thought.  Still, cause, object, and feeling seems like a useful framework.  Maybe it explains why it can be hard to tell what emotion another person is having.  You have to know what their feeling is, who it's directed towards --- the object --- and why, the cause.

At any rate, if inner feelings are in part definitive of a person’s emotions, that explains why it seems that it would be hard to figure out another person's emotions; perhaps impossible to know that one is right, given the ability of people to pretend.  But in fact, it isn’t so hard, and certainly not impossible.  That’s where faces come in.  We are in fact very good at detecting other people's emotions, sometimes better than we do our own, and it has to do with faces.  Actors learn to express a wide range of emotions, by learning the right facial expression.  And today, our guest is one of the world’s foremost authorities on faces and emotions, San Francisco’s very own Paul Ekman.  He has discovered that fleeting changes in faces, what he calls ``micro-expressions”, are surprisingly reliable guides to a person’s emotions, particularly those involved in lying.