Part I How can we know who is happy? Conceptual and methodological issues -- Objective happiness / Daniel Kahneman -- Ecological momentary assessment / Arthur A. Stone, Sual S. Shiffman, Marten W. DeVries -- Measurement issues in emotion research / Randy J. Larsen and Barbara L. Fredrickson --...

Emotion and rationality are fundamental elements of human life. They are abstract concepts, often difficult to define and grasp. Thus throughout the history of Western society, the head and the heart, concrete and identifiable elements, have been used as symbols of rationality and emotion....