Visceral responses to the social environment.

Twenty-five hundred years ago, Hippocrates, recognizing the impact of life experience on health wrote: "those things which one has been accustomed to for a long time, although worse than things to which one is not accustomed, usually give less disturbance" (Bruhn & Wolf 1978). Since Hippocrates, much evidence has emerged to suggest that social stability is conducive to health, while social change, especially rapid change, may predispose to illness. The idea that sensory information from ordinary life experiences contributes in a major way to shaping the activities of the brain, took root in the 18th century with Pierre Gassendi and John Locke. A mechanism whereby the vast numbers of neurons in the brain could be rapidly rearranged and organized to respond to a host of different external stimuli emerged from the work of Santiago Ramon y Cajal who discovered the axonal growth cone and its capacity to elongate and guide an axon a considerable distance to a target dendrite (Cajal 1890). Thereby, with very rapid shifts in attention and perception, a wide range of responses, emotional, and physiological can be elicited. With this and other evidence at hand that the intracranial regulatory mechanisms can reorganize in response to environmental change including social change, we undertook a 30 year (1962-1992) prospective study of the effects of social patterns on health in Roseto, a closely knit Italian-American incorporated town in Pennsylvania. It was settled in 1882 by Italians from Roseto val Fortore, a town in southern Italy near the Adriatic Sea. We found a sharp increase in myocardial infarction among Rosetans when long established cohesive social patterns began to weaken and be replaced by more egocentric attitudes.