This book examines well-known rituals, customs, and traditions of human life from a psychological perspective: What new insights does modern science offer regarding the often ancient rituals of our individual or societal lives that continue to influence us today? The authors juxtapose new psychological explanations with historical backgrounds, thereby expanding our understanding of why certain customs exist, what functions they serve for our (co-)existence, and why some rituals have persisted while others have been abandoned or modified over time. Additionally, the book provides remarkable insights into human judgment, thinking, and behavior, along with concrete tips for our actions, such as in education in kindergartens and schools, leadership in companies, and in politics.