The Brain, Homeostasis, and Health Balancing Demands of the Internal and External Milieu

The biologist Richard Lewontin (2000) characterized living organisms as electromechanical devices made up of articulated physical parts that, for purely thermodynamic reasons, eventually wear out and fail to function. Lithgow and Kirkwood (1996), in their review of research on the biology of aging, observed that it is “disadvantageous to increase maintenance beyond a level sufficient to keep the organism in good shape through its natural life expectancy in the wild, because the extra cost will eat into resources that in terms of natural selection are better used to boost other functions that will enhance fitness” (p. 80). We are only now beginning to understand how the brain integrates the regulatory and restorative forces of the body to foster health and adaptation to environmental challenge. This chapter examines these forces as they relate to psychology and health.