Book excerpt: Few of us, amidst our daily chores and responsibilities, consider how mundane infrastructures—from electrical grids to sewage systems—have developed over millennia in ways that enable everything we cherish, from democracy to technological innovation to individual liberty. But what drives the evolution of this infrastructure? And why is infrastructure so critical to human flourishing? In this book, the most innovative and interdisciplinary study of cultural evolution ever produced, new concepts are explored, new histories are brought into contact and new ground-breaking insights are defended. What makes creativity unique in human societies is not only our capacity to generate and modify our diverse individual intuitions about the social and physical world, but also our capacity to form and leave groups fluidly in a dancing rhythm of oscillation across the expanse of history. This book walks the reader carefully through these processes, with clear concepts and an approachable writing style.