This book uses new research and theory to present the first state-of-the-art account of children's understanding of biology and health. Each of the contributors views children's understanding in these areas to be to some extent adaptive to their well-being and survival and uses evidence collected through a variety of different techniques to consider whether young children are capable of basic theorising and understanding of health and illness. Topics ranging from babies to the elderly including birth, death, contamination and contagion, food and pain are examined and close links between research and practice are made with obvious attendant benefits in terms of education and communication. The combination of theory and practice will guarantee the appeal of this book to an international audience of advanced undergraduate and postgraduate students and professionals in areas such as education, child welfare, medicine and law.