Imitation guides the behaviour of a range of species. Recent scientific advances in the study of imitation at multiple levels from neurons to behaviour have far-reaching implications for cognitive science, neuroscience, and evolutionary and developmental psychology. This volume provides a state-of-the-art summary of the research on imitation in both Europe and America, including work on infants, adults, and nonhuman primates, with speculations about robotics. A special feature of the book is that it provides a concrete instance of the links between developmental psychology, neuroscience, and cognitive science. It showcases how an interdisciplinary approach to imitation can illuminate long-standing problems in the brain sciences, including consciousness, self, perception-action coding, theory of mind, and intersubjectivity. The book addresses what it means to be human and how we get that way.