[Summary] In the book "Understanding Emotions,” Dacher Keltner, Keith Oatley, and Jennifer M. Jenkins explore the science of emotions, examining their biological, psychological, and social aspects. The book focuses on the various components of emotional experience, such as appraisal, regulation, and expression. The authors also explore the role of emotions in human evolution, social interactions, and cultural differences. The text further examines the influence of emotions on mental health, well-being, and interpersonal relationships.