Most people think that happiness has four sources: the sensory pleasures, material wealth, romantic relationships, and children. But recent research suggests that much of what people think about happiness is wrong. Daniel Gilbert, author of "Stumbling on Happiness," hosts this symposium in which experts discuss what science has discovered about each of these sources. The featured speakers are Paul Bloom, author of "How Pleasure Works"; Tim Kasser, author of "The High Price of Materialism"; Eli Finkel, author of "The All-Or-Nothing Marriage"; and Jennifer Senior, author of "All Joy and No Fun."