Human adaptation to levels of environmental stimulation

This paper examines the environment as a source of dimensions of stimulation that are directly related to the individual's affective response to his environment, and his behavioral adaptation to it. The concept of an optimal level of stimulation is introduced, along with a view of environmental stress as resulting from conditions of excessive deviation from such optimal levels, with particular reference to variations in intensity, diversity, and patterning of the stimulus input. This analysis provides the framework for a consideration of behavioral adaptation to the environment by reference to the concept of adaptation level. Levels of adaptation to particular environmental dimensions, established as a function of past exposure, are shown to act as potent determiners of the individual's evaluation of his environment, as well as representing a plausible basis for the optimal level of stimulation principle itself. The presentation proceeds to an examination of the process of adaptation to the environment as a multilayered process, and to a discussion of the concept of the cost of adaptation as it applies in the behavioral realm. Finally, adaptation is contrasted with an alternative mechanism, adjustment, involving active alteration of the environment by the individual, and the relative place to be accorded to these two processes in the individual's relation to the environment is considered.