An Invariant Function Interpretation of Developmental Process

On descriptive level, developmental processes of organisms in general can be studied in terms of growth pattern. At different developmental stages, the behavior pattern specific to that stage can be identified by observation. The idea of growth pattern assumes that there exist certain behavior processes which are fairly independent of evironmental interaction. In other words, certain behavior patterns are to a great extent common to the same species of animals at a certain stage of development, and not easily changed by environmental effect. This is what is meant by the term invariance. The Next step is to make clear the concept of environmental effect. For this purpose it is useful to look at the proper subject of behavior theory. The major questions in behavior theory concern the necessary an sufficient conditions for the occurrence of relatively permanent behavior change not due to maturation process and the laws which govern the processes of this behavior modification. Then the term environmental effect can be identified with the reinforcement procedure in behavior theory.