Emotion represents a core element of human life, as our thoughts and behavior are influenced by the complex and interrelated set of feelings we all experience. As such, developing an understanding of the role emotion plays in human psychology is essential not only in the treatment of mental illnesses, but for the optimization of overall well-being. This book includes five chapters, each presenting research concerning various aspects of emotion. Chapter One discusses the most effective treatments for emotion dysregulation and emotional disorders, focusing on therapies that target emotional regulation. Chapter Two examines the impact of emotions on learning processes, particularly how emotions evolve in the context of clinical reasoning, which aims to reduce the incidence of medical errors. Chapter Three draws from socio-cognitive and cultural studies to analyze the relations between emotions and social representations of the past. Chapter Four introduces three studies on Japanese children’s understanding of guilt. Finally, Chapter Five presents an integrated view of current studies on how consumers’ purchases impact their emotions, particularly their happiness.