Peter B. Dews (1922–2012)

Peter B. Dews (1922–2012), who passed away on November 2, is considered quite appropriately to be the principal founder of the discipline of behavioral pharmacology, a discipline that examines the effects of drugs on behavior. An important feature of this discipline, and one that can be traced to Dews's initial studies, is the previously unrecognized contribution of behavior to the actions of a drug. Throughout his career, his research had a major impact not only on the emerging field of behavioral pharmacology but also on the experimental analysis of behavior, where he probed deeply into the analysis of schedule-controlled responding. In his research on the behavioral effects of drugs and on the analysis of behavior, a central theme was Dews's emphasis on the exquisite control and opportunities provided through the use of schedules of reinforcement. Peter received his medical degree from the University of Leeds in 1944 working under W. H. Bain. He left the Department of Pharmacology at the University of Leeds to work with J. H. Burn at Oxford University and then went on to spend time working with Sir John Henry Gaddum at the University of Edinburgh. In 1948 he moved to the United States under a research fellowship to a position at Burroughs Wellcome in New York. When he took a faculty position in 1953 at Harvard Medical School in the Department of Pharmacology under the direction of Otto Krayer, Peter was introduced to research being conducted in the Department of Psychology at Harvard University by B. F. Skinner and C. B. Ferster on schedules of reinforcement. Peter was struck with the objective and quantifiable methods that had been developed in Skinner's laboratory that were being studied using pigeons as experimental subjects. In a retrospective on this experience, he has said that “it was immediately apparent from the counters and cumulative records that behavioral phenomena were being studied in a way that was well suited for application to pharmacology” (Dews, 1987, p. 460). With borrowed apparatus and with the help of Ferster, Peter incorporated those techniques into his first studies with drugs and thereafter was committed to an experimental analysis of behavior and to a more detailed analysis of the behavioral effects of drugs. These early years in Peter's career and in the development of his research in behavioral pharmacology, as well as the founding of the Journal of the Experimental Analysis of Behavior, have been summarized in “Reminiscences of JEAB” (Dews, 1987). With his pioneering publication entitled “Studies on Behavior” (Dews, 1955), conducted with pigeons responding under fixed-ratio or fixed-interval schedules, he reported that the effects of pentobarbital depended on the schedule of reinforcement. Pentobarbital produced increases in responding under the fixed-ratio schedule at the same doses that decreased responding maintained under the fixed-interval schedule. The influence of the schedule of reinforcement on the effects of pentobarbital was striking and led to a recurring emphasis on the importance of behavioral consequences and on the influence of schedules in much of Peter's subsequent contributions to both behavior analysis and to the study of the behavioral effects of drugs. The results obtained with pentobarbital, typically characterized as a central nervous system depressant, clearly had both stimulant- and depressant-like effects, with those effects depending on the schedule of reinforcement that controlled behavior. His initial publication of “Studies on Behavior” and the series of articles that followed represent significant scientific landmarks that unquestionably established the foundation as well as the guideposts for the emergence and growth of the discipline of behavioral pharmacology. Dews viewed schedules as central principles that governed behavior and considered them to be as fundamental to behavior as osmosis is to physiology and evolution is to the selection and propagation of species. In a discussion of schedules and addiction, Dews (1973) commented that “evolution has produced subjects who are controlled by schedules; the control is a powerful determinant of behavior, be it adaptive or maladaptive” (pp. 44–45). The emphasis on schedules of reinforcement weaves together many threads in the fabric of Peter's work, whether he was discussing the specific effects of drugs under different experimental conditions or extrapolating to more global concepts such as “humors” (Dews, 1964), addiction (Dews, 1973), analgesia (Dews, 1974), or neurotransmitters (Dews, 1975). These extrapolations added further strength to the rationale for studying schedules of reinforcement and expanded the dimensions and the potential applications of schedule-controlled behavior. His penetrating insight, together with his expansive and often poetic application of the principles and concepts that underlie schedule-controlled behavior, have inspired many and were advanced with a foresight that foreshadowed several findings that were to be supported experimentally in the years to follow. Many of these contributions and their impact on the experimental analysis of behavior and on behavioral pharmacology have been summarized in recent testimonials to Peter's contributions to the origins of behavioral pharmacology and to behavioral research (Barrett, 2006, 2013; Barrett & Bergman, 2008; Morse, 2013). The period in the mid-1950s was an exciting time in pharmacology; chlorpromazine had recently been discovered and introduced into treatment for schizophrenia, and other new therapeutics followed rapidly. It was also an exciting time at Harvard with the focus of Skinner's laboratory on the development and analysis of schedules of reinforcement, which led to the publication of Schedules of Reinforcement (Ferster & Skinner, 1957), followed shortly by the emergence of the Journal of the Experimental Analysis of Behavior (JEAB). As mentioned previously, Dews fully appreciated the techniques that were developed to control behavior through the use of schedules of reinforcement and creatively incorporated them into his pharmacological studies. It is also true, although perhaps not as fully recognized, that he conducted a very large number of studies on schedule-controlled behavior in the absence of drugs. These experiments, published in JEAB over a 7-year period from 1962 to 1969, consisted of an extensive analysis of fixed-interval schedules in which he systematically manipulated a variety of interventions in an effort to dissect the characteristic scalloped pattern of responding maintained under these schedules. The results of his many experiments in this area were summarized in a chapter on the analysis of fixed-interval performances that represents one of the most comprehensive analyses of performance under this schedule to date (Dews, 1970). At the time of these early developments in the experimental analysis of behavior and behavioral pharmacology, there were a number of psychological theories about drug effects, emotions, and motivation. Again, the clarity of thought and the expressive manner in which Dews addressed these complex issues was refreshing for many who eschewed the overtheorizing frequently associated with psychology. His framework for the analysis of both behavior and of drug effects is perhaps best conveyed in a quote from one of his early publications: Traditionally, behavioral effects of drugs are attributed to effects of the drugs on emotions such as fear and anxiety, and on ambitions, inhibitions, drives, and other hypothetical or arbitrarily defined “states.” The system of experimentation under discussion leads logically to a different approach; it leads to an analysis in operationally defined terms. (1956, p. 274) Peter's emphasis was focused on behavior and on the variables that control behavior as they are expressed in determining the actions of various drugs. His emphasis on behavior and the environment were central themes that emerged from his work. Behavior was much more than a transducer or transmitter of drug effects, and this conceptual emphasis was crucial to the growth of the field. His understanding of both behavioral processes and the principles of pharmacology, together with the elegance and expansive expressions contained in his writings, were significant contributions to the development of the discipline of behavioral pharmacology. Infrequently, a new discipline is founded, undergoes growth and expansion, and gathers a group of enthusiastic scientists and students who eagerly embrace and attempt to contribute to building the foundation of that new discipline. Dews captured and further developed the established principles and techniques of behavior analysis and drug action to embrace new concepts while he simultaneously attempted to bridge, when appropriate, with other disciplines. His experimental work and his extrapolations to general concepts combined to passionately inspire those who followed. This is the legacy of Peter B. Dews. The disciplines of both behavioral pharmacology and the experimental analysis of behavior are enduring testimonies to his spirited and profound contributions. Peter was elected to membership in the American Academy of Arts and Sciences in 1964 and to the Institute of Medicine in 1984. He is survived by his wife, Grace; a sister, Jean Hilditch; his daughter, Pamela Rentschler; and his sons Kenneth, Alan, and Michael; as well as nine grandchildren and one great-grandchild.