An interactionist looks at the environment.

FOR this occasion I have chosen to focus on some major developing trends in the science of psychology which involve the systematic, multivariate study of the environment. This discussion is related to, but will advance beyond, the basic arguments presented in my recent symposium volume (Sells, 1963b) on Stimulus Determinants of Behavior. Although contemporary psychological theory is often criticized on the grounds of its many diverse and incompatible ideological positions, there are nevertheless a number of significant basic postulates that enjoy widespread, if not universal, acceptance, and which are common to those, at least, that represent psychology as a science. I wish to present three such postulates, as a frame of reference for the discussion to follow. These are: 1. All scientific theories of behavior accept some statement of the principle of determinism, with only minor variations, even though unexplained variance and experimental error arc frequently disconcertingly large in empirical data. 2. All contemporary theorists implicitly or explicitly accept the principle of the multiple determination of behavior, which implies that neither stimuli nor responses occur in isolation, but rather in patterned, sequential, and ordered complex relationships. Attitudes vary widely toward this characteristic aspect of behavior and major variations in choice of problems, methodology, and preferred levels of conceptual and experimental operation have resulted as a consequence. Nevertheless, the complexities arc not and cannot be denied. 3. Finally, all theorists appear to agree that behavior, even at the most primitive levels, represents the result of some form of mediated transaction between organism and environment. Let us call this the principle of interaction, expressed by the