Behavior, the environment, and the health of the individual

The contribution of medical treatment to the health of the world's population was virtually nil until the 20th century and continues to be small. In contrast, the contribution of the prevention of disease through modification of the environment (improved ventilation, drainage, sewage disposal) has been great. This effect is seen in the dramatic rise in the population of Europe since the early 18th century. The major causes of death and disability in developed countries, however, have changed markedly during the present century. Most of the risk factors associated with these diseases are behavioral in nature (cigarette smoking, excessive caloric intake, excessive alcohol consumption, inadequate exercise, etc.). Accordingly, modifying the environment is no longer enough--one must modify the behavior of the individual. To do this, one needs an effective technology for modifying behaviors that have important health consequences. Such a behavioral technology is being developed. Some of the principles underlying this technology will be illustrated by their application to one modern scourge--cigarette smoking.