The concept of stress pervades modern society, yet there exists no generally accepted definition or classification of stressful experience. This authoritative work is the first to analyze critically the entire range of research and theory on stress in animals and humans, from W.B. Cannon and H. Selye's earliest studies in the 1930s up to the present day. Herbert Weiner not only documents the many empirical and conceptual advances of recent years, but also produces a new definition of stress in organismal terms and provides a classification of the various kinds of stressful experience. Because Cannon and Selye's approaches emphasized physiological and medical aspects, the concept of stress soon became inextricably linked to unavoidable and often overwhelming agents such as injury and infection. Overlooked in the early accounts was that all organisms face many additional types of natural challenges and obstacles in their efforts to survive and reproduce: for example, they must fight or escape predators, replenish diminished food supplies, and anticipate, seasonal changes of climate. Weiner's survey of the literature shows that much progress has been made in understanding the effects of exposing animals to these kinds of naturally occurring stressful experiences and their varied outcomes. Under such conditions there appear patterns of integrated behavioral and physiological responses that are exquisitely attuned to the experience. He carefully assesses the research on the ways in which neural circuits and peptidergic mechanisms in the brain generate and integrate these patterns. In addition, he presents new concepts about the perturbation of subsystems, including biological clocks, which may, or may not, lead to disease or ill-health. Perturbing the Organism is the first book to analyze in detail the relevant research in experimental psychology, psychiatry, medicine, endocrinology, immunology, and psychoneuroimmunology to provide a useful, integrative concept of stress--one that is rooted in an understanding of the organism as an interactive communication system composed of many subsystems. It will interest a wide range of clinicians and researchers throughout the medical and behavioral sciences.