Feedback: beyond behaviorism.

Consistent behavior patterns are created by variable acts, and generally repeat only because detailed acts change. The accepted explanation of this paradox, that "cues" cause the changes, is irrelevant; it is unsupported by evidence, and incapable of dealing with novel situations. The apparent purposefulness of variations of behavioral acts can be accepted as fact in the framework of a control-system model of behavior. A control system, properly organized for its environment, will produce whatever output is required in order to achieve a constant sensed result, even in the presence of unpredictable disturbances. A control-system model of the brain provides a physical explanation for the existence of goals or purposes, and shows that behavior is the control of input, not output. A systematic investigation of controlled quantities can reveal an organism's structure of control systems. The structure is hierarchical, in that some quantities are controlled as the means for controlling higher-order quantities. The output of a higher-order system is not a muscle force, but a reference level (variable) for a lower-order controlled quantity. The highest-order reference levels are inherited and are associated with the meta-behavior termed reorganization. When controlled quantities are discovered, the related stimulus-response laws become trivially predictable. Variability of behavior all but disappears once controlled quantities are known. Behavior itself is seen in terms of this model to be self-determined in a specific and highly significant sense that calls into serious doubt the ultimate feasibility of operant conditioning of human beings by other human beings.