Book excerpt: Do children have a theory of mind? If they do, at what age is it acquired? What is the content of the theory, and how does it differ from that of adults? "The Child's Theory of Mind "integrates the diverse strands of this rapidly expanding field of study. It charts children's knowledge about a fundamental topic - the mind and characterizes that developing knowledge as a coherent commonsense theory, strongly advancing the understanding of everyday theories as well as the commonsense theory of mind.Henry M. Wellman is a Professor in the Department of Psychology and the Center for Human Growth and Development at the University of Michigan at Ann Arbor.