Verbal understanding and Pavlovian processes.

The behavioral processes through which people react appropriately to verbal descriptions remain poorly understood. I argue here that these processes are Pavlovian. Common objections to a Pavlovian account of symbolic behavior evidence a lack of familiarity with the relevant data or misunderstandings of operant theory. Although much remains to be done to explore the relation between verbal understanding and simpler forms of Pavlovian conditioning, the similarity of these two sets of phenomena has received increasing support in recent years. The difficulties of operant principles in accounting for symbolic behavior have a more general implication: Operant models, which focus on the maintenance of responding, must incorporate principles of behavioral induction that explain the origins of novel environment-behavior relations. Pavlovian processes are likely to contribute. Keywords: symbolic behavior, functional equivalence, Pavlovian conditioning, humans. How do words acquire their meaning? The problems associated with meaning and reference involve many dimensions. The fact that we can still refer today to Marco Polo's travel to China involves an initial connection of verbal behavior with a nonverbal referent, and a long chain of behavioral events that preserve meaning across linguistic communities. The issue of meaning therefore transcends the boundaries of psychology to involve social and cultural invariances holding from one generation to the next (Kripke, 1972; Putnam, 1975). Behavioral psychologists, who deal with the adjustments of individual organisms, cannot address this problem in its entirety. But they can elucidate the processes involved in how a person understands a sentence or reacts to the description of a situation. Behavioral psychologists can study how and why being told that swimming in the river is dangerous leads us to avoid swimming, how and why being told that the pie is delicious leads us to order a slice. In each case, the problem of verbal understanding has clear behavioral dimensions: Exposure to an organized set of verbal stimuli (including words such as "river" or "pie") later leads to a change of behavior with respect to their nonverbal referents. Verbal understanding has not been explained convincingly within Skinner's (1957, 1969) traditional operant framework, however. Most of the research inspired from Verbal Behavior (Skinner, 1957) involves the reinforcement of elementary verbal operants and focuses on the behavior of the speaker (Oah & Dickinson, 1989); verbal understanding, which concerns the behavior of the listener (Parrott, 1984, 1987), has been neglected or addressed in a deficient fashion. In the absence of a coherent specification of the underlying behavioral processes, for example, the concept of rule governance (Skinner, 1969) is merely an empty label. If we agree to call an instruction a "rule," then instruction-following is by definition a case of "rule governance," but pointing out the obvious does not lead us any closer to a scientific understanding of the relevant behavioral phenomena. The lack of progress in addressing verbal understanding from a standard operant perspective may arise in part from empirical difficulties, but also signal more basic deficiencies with reinforcement-based accounts. Their central deficiency can be understood by contrasting directly reinforced with derived behavioral functions. In the former case, the response distribution observed conditionally on a stimulus A arises from reinforcement in the presence of this stimulus or physically similar ones. In the latter case, the response distribution observed conditionally on A arises from reinforcement in the presence of a stimulus B distinct from A (and that entertains no formal similarity with A). Until recently, basic behavior-analytic research dealt almost exclusively with the former case, the study of which (Skinner, 1938) was taken as a model for the explanation of verbal behavior (Skinner, 1957). …