Plasticity refers to the ability of many organisms to change their biology or behaviour to respond to changes in the environment, particularly when these are stressful. Humans are, perhaps, the most plastic of all species, and hence the most variable. This book reflects on the history of research in this area, state-of-the-art research methods and discoveries and needs for future research in human plasticity and variability. Topics discussed include child growth, starvation, disease of both young and old and the effects of migration, modernisation and other life-style changes. The book will be especially useful to biological anthropologists, human biologists and medical scientists interested in knowing more about how and why humans vary.