Most of us are continually aware that others have thoughts and feelings - but are children? When? This book is a concise and readable review of the extensive research into children's understanding of what other people think and feel, a central topic in developmental psychology known as "Theory of Mind". The understanding of belief is central to this text, which explains in simple terms what representational theory of mind is all about, and shows how researchers have demonstrated this understanding in 4-year-olds. The book considers what leads to this understanding, including the role of pretend play, understanding of attention and eye direction, and other precursors to representational understanding of mind. The general relevance of theory of mind is demonstrated through coverage of the development of other mental state concepts, and the relationship between understanding mental representation and other representational media. The author also carefully summarizes current research on the relationship between theory of mind and concurrent developments in executive functioning, and the understanding of language. The book closes by considering autism. A major achievement of theory of mind research is the light it has helped throw on this puzzling developmental disorder. Providing a comprehensive overview of 25 years of research into theory of mind, the book will be of great interest to both students and researchers in psychology, philosophy and the cognitive sciences.