What motivates us to work? Contrary to conventional wisdom, it isn't just money. But it's not exactly joy either. It seems that most of us thrive by making constant progress and feeling a sense of purpose. Behavioral economist Dan Ariely presents two eye-opening experiments that reveal our unexpected and nuanced attitudes toward meaning in our work. It's become increasingly obvious that the dismal science of economics is not as firmly grounded in actual behavior as was once supposed.