The concept of intersubjectivity, explicit or implicit, has emerged as a common denominator in approaches to interpersonal engagements in early infancy and children's understanding of others' thought and emotion. This 1999 book brings together the most senior international figures in psychology, psychopathology, sociology and primatology to address the key question of the role of intersubjectivity in early ontogeny. Together, they offer an interesting perspective on child development, learning and communication and highlight important comparisons with processes in autistic development and in infant ape development. The book is divided into four parts, focusing on intersubjective attunement in human infancy; companionship and emotional responsiveness in early childhood; imitation, emotion and understanding in primate communication; and intersubjective attunement and emotion in language learning and language use. It is an invaluable resource for researchers in emotion and communication across the social and behavioural sciences.