Psychology professor Paul Ekman. His new book is “Emotions Revealed: Recognizing Faces And Feelings To Improve Communication And Emotional Life.” Ekman describes how facial expressions work. For example, he can tell the difference between a fake and a real smile by mapping the muscle movements of both. Ekman is professor of psychology in the department of psychiatry at the University of California Medical School, San Francisco. He frequently consults for government agencies like the FBI.