B. F. Skinner (1904-1990)

Fred Skinner, as his friends called him, was born in Susquehanna, Pennsylvania. His father was a lawyer. His mother was a homemaker who kept close watch on her two sons. (Skinner’s brother died of an accident at the age of 16.) Skinner exhibited early on a knack for solving problems using mechanical devices, a skill that would play a crucial

FYI: Skinner’s Apparatus-Skinner invented two pieces of laboratory apparatus that were instrumental in the development of radical behaviorism. One was the operant conditioning chamber or Skinner Box. The other was the cumulative recorder. He made Skinner boxes suitable for rats and pigeons. In rat chambers the response was a lever press while in pigeon chambers the response was a peck on a target disk (see Figure 11.4). A small bit of food or water served as the reinforcer. The chamber itself was the discriminative stimulus but other discriminative stimuli (e.g., lights or tones) could be added. The dependent variable in a Skinner Box was the rate of response (number of responses over time) which was measured by the cumulative recorder. During World War II Skinner engineered an apparatus for pigeons housed inside bombs. The pigeons could guide the bomb to the target by pecking at a display. The device worked but was never operationally deployed. After the war, Skinner made an Air Crib in which he and his wife, Yvonne, raised their second daughter. He made the Air Crib for their second child, Deborah, partly to keep her warm in the Minnesota weather without having to

Air Crib, Rat Operant Chamber, Pigeon Operant Chamber, Teaching Machine,

bundle her with layers of clothing. Skinner attempted to market the device but it never caught on, especially following an article in the Ladies Home Journal magazine (Skinner, 1945) that described it as an experiment in child rearing. Urban legends circulated that Deborah had either gone crazy or committed suicide. Those legends were untrue; she was a well-adjusted child and a successful adult (Joyce & Faye, 2010).

role in his later research. He was a good student, attended Hamilton College where he majored in English. His goal then was to be a writer. After he graduated he attempted to write short fiction unsuccessfully. In his autobiography (1970, p. 7), he wrote, “I had failed as a writer, because I had nothing important to say, but I could not accept that explanation.” After reading Russell’s (1927) Philosophy along with Watson’s and Pavlov’s works he adopted behaviorism although the radical behaviorism he created later would be much different than anything that he had learned at school. He went to Harvard to study psychology and received his PhD in 1931; he remained there five more years as a fellow. A discussion with the philosopher Alfred North Whitehead at a fellow’s dinner proved seminal to Skinner’s later theorizing. Whitehead challenged Skinner to demonstrate that studying language scientifically was possible. Skinner’s response, however, was long delayed. It came in the form of a book (Skinner, 1957), Verbal Behavior, a work he considered to have been his most important contribution to psychology. Following his years as a fellow, Skinner first worked at the University of Minnesota for nine years followed by three years as chair at the University of Indiana. In 1948 he returned to Harvard where he remained as an active faculty member until his retirement in 1974. However, he continued to work and publish there as professor emeritus until his very last days of life. His final public appearance was at the American Psychological Association’s 1990 meeting just days before his death. There, he reaffirmed his commitment to radical behaviorism in the face of the “cognitive revolution” which had swept through psychology during his lifetime. In his speech, delivered before a standing room only crowd, he proclaimed, “Cognitive science is the creation science of psychology, as it struggles to maintain the position of a mind or self” (Skinner, 1990, p. 1209). What legacy to psychology, exactly, did Skinner leave with his radical behaviorism?

Border with Biology: Radical Behaviorism-As far as radical behaviorists are concerned no border exists between psychology and biology. In fact, they consider radical behaviorism to be a part of biological science. Borrowing the mechanism of selection from evolutionary theory, they argue that it operates at three levels. The first level is Darwin’s natural selection that selects organisms whose genes allow them to reproduce and become more numerous. Innate behaviors come from this level. The second level is operant conditioning that selects organisms’ emitted behaviors (or operants) through the action of the environment. Those selected behaviors also “reproduce” and become more numerous. Learned behaviors in animals and humans come from this level. The final level is cultural where humans’ verbal responses (also considered to be operants) are selected through the action of the linguistic communities people live in. The verbal responses selected by the linguistic community a person lives in also become more numerous. Culturally based behaviors in humans come from this level. Radical behaviorism interprets each type of selection at its own level with each possessing its own time frame. So, phylogenetically based innate behaviors evolved over millions of years. Learned behaviors in animals and humans develop over the course of the lifetimes of individual species members. Culturally based behaviors also evolve over long periods, from as little as several lifetimes to thousands of years. In terms of theory, radical behaviorists confine themselves to the last two levels but take pains to demonstrate that at all three levels either genes, behaviors, or verbal behaviors are being selected mechanistically according to environmental consequences operating at their respective levels.

Radical Behaviorism

Radical behaviorism is, by design and intent, completely different from Watson’s behaviorism and other neobehaviorist formulations. Radical behaviorism, however, preserves Watson’s definition of psychology, the prediction and control of behavior. But, radical behaviorism rejects other neobehaviorist theories because of their use of intervening variables; those are rejected because they are mentalistic and because they assume dualism (which is mentalistic as well). At the same time radical behaviorism is not S-R psychology either. Instead, it explains learned behavior through selection by

Marginal Definition: mentalism-explaining behavior by recourse to variables such as cognitions, memories, or motivations.

consequences. Operant conditioning occurs when a response is followed by a reinforcer causing that response to be emitted more often. Organisms also learn the environmental occasions when reinforcement is likely. Skinner diagrammed the relationship as follows:

S^D --> R --> S^R

where the S^D is the discriminative stimulus, R is the emitted response, and S^R is the reinforcer. In the laboratory specifying the three terms above is relatively easy. Outside of the laboratory the search for discriminative stimuli and reinforcers is more difficult but still quite possible. A branch of radical behaviorism, applied behavior analysis,

Marginal Definition: applied behavior analysis-the design, application, and assessment of environmental modifications that lead to improvements in human behavior in the real world using principles derived from radical behaviorism.

specializes in searching for and understanding how operants or discriminative stimuli are at work in natural situations. Some applied behavior analysts work in clinical areas of psychology and use their knowledge to alter patients’ environments in ways that lead to positive outcomes to health or adjustment. Behavior modification is one of the techniques

used by applied behavior analysts. It consists of imposing new and consistent environmental contingencies in real world situations such as classrooms. Nearly every elementary and secondary teacher in the United States is at least aware of behavior modification and many use it to manage their classrooms effectively and efficiently.

Border with Social Science: Token Economies in the Classroom-Token economies, a type of applied behavior analysis, have been created for a wide variety of natural situations. All varieties are similar in that they use tokens (e.g., arbitrary items such as poker chips or stickers) as conditioned reinforcers. The tokens may be cashed in for primary reinforcers such as food according to a published schedule. A classroom token economy is a form of contingency management where students may earn tokens for following explicit, behaviorally based classroom rules. A recent study (Little & Akin-Little, 2008) revealed that 73% of teachers surveyed had created their own set of classroom rules. However, Maggin et al. (in press) reviewed 24 studies of classroom token economies and concluded “students generally respond to these types of interventions” but that “practitioners need to be aware that the use of token economies in schools and classrooms likely requires careful oversight and systematic protocols for delivering generalized conditioned and secondary reinforcement” (p. xxx). They also called for more rigorous research that better reported student characteristics and contexts in which token economies are designed and delivered. Despite the fact that managing behavioral contingencies in the real world is more difficult than doing so in the laboratory, many teachers do so successfully every day.

Understanding Skinner

DeBell and Harless (1992) examined common misunderstandings about Skinner using a short quiz that they administered to psychology students and faculty. They identified five common misperceptions or myths: “(a) the role of physiology and genetics in behavior, (b) the extent to which all behavior can be conditioned, (c) the uniqueness of the individual, (d) the use of punishment in controlling behavior, and (e) the existence of internal states” (p. 68). Their quiz had 14 questions, half of which were filler questions about Skinner that did not relate to the myths above; the other half addressed the five myths. Here is their quiz. The answers are on page xxx.

--------------Table 11.1 Insert DeBell and Harless quiz and answers about here--------------

Interestingly, even psychology faculty missed more than half of the myth questions. Advanced undergraduates missed nearly all of them!

Skinner understood that physiology and genetics played an important role in behavior and that innate behaviors existed. Innate behaviors were the result of natural selection. However, the conditions that originally led to their selection could change, albeit slowly, as the environment changed. When it changed so did its selection pressures. Organisms either adapted or went extinct. Also, behaviors that were adaptive at one point in phylogenetic history might become maladaptive at a later point, the flight or flight response in humans, for instance. In the distant past it served an obvious adaptive purpose, it led to escape from danger. But, in the modern, industrialized world it had become maladaptive as it contributes to increased levels of hypertension and risk of heart attacks.

Skinner never claimed that all behavior was modifiable by operant conditioning; contingencies at the phylogenetic level or the cultural level might prevent it. However, operant conditioning was the major mechanism operating during a person’s life. Over the course of a person’s lifetime the environment would select behaviors that were followed by reinforcement and extinguish those that were not.

Skinner believed in human uniqueness and maintained that, except in the case of identical twins, all persons had been uniquely shaped by genetics, their environments, and the cultures they lived in. His research strategy reflected that belief. He conducted research on only a few organisms at a time and eschewed the use of large groups and the concomitant reliance upon statistical analysis. Instead, he argued for visual inspection of large amounts of data collected from only a few individuals. One of his innovations was the N = 1 research design where a single individual animal or human is subjected to successive experimental manipulations (see Kennedy, 2004 for more information on single case designs). One of the most common N = 1 designs is the ABA design. In it, the organism is observed in its environment without altering any behavioral contingencies. The purpose of that is to determine a baseline or control. This is the A part of the ABA

Marginal definition: baseline-the environmental situation or context that exists before a treatment or intervention is applied.

design. Next, the experimenter alters a contingency (this is the B part) and looks for a change in the rate of responding. This step is the intervention. If a change occurs then

Marginal definition: intervention-a specific alteration to the baseline condition designed to change the response rate initially observed.

the next step is to remove the contingency and observe whether the rate of responding returns to the baseline rate. These steps may be repeated (e.g., ABABABAB...) and if the rate of responding consistently changes then the researcher can infer that the intervention was causally responsible for the change in behavior. The ABA design is often used in applied behavior analysis to discover interventions that will change people’s behaviors. For Skinner, then, each individual and each situation was unique. Introducing large group designs and analyzing them statistically only confused understanding, he believed.

Skinner also differentiated strongly between reinforcement and punishment. Although both are similar structurally, but in opposite directions, they are quite dissimilar in their long-term effects. Reinforcement follows a response and strengthens it and punishment follows a response and suppresses it. But, the structural similarity ends there. Skinner (1953) offered three reasons why punishments should not be administered: they only work temporarily, they create conditioned stimuli that lead to negative emotional reactions, and they reinforce escape from the conditioned situation in the future. He wrote (pp. 192-193):

Civilized man has made some progress in turning from punishment to alternative forms of control...But we are still a long way from exploiting the alternatives, and we are not likely to make any real advance so long as our information about punishment and the alternatives to punishment remains at the level of casual observation. As a consistent picture of the extremely complex consequences of punishment emerges from analytical research, we may gain the confidence and skill needed to design alternative procedures in the clinic, in education, in industry, in politics, and in other practical fields.

Skinner’s view on internal states is probably the most startling example of his way of thinking about behaviorism. He rejects any idea that a separate mental world exists. At the same time, however, he makes possible an analysis of the environment inside the skin. Each person thus is affected only by the environment, but that environment consists of two parts: a public one potentially accessible to all and a private one accessible only to one’s self. So, as of right now there exist about seven billion human private environments, one inside each person alive today. Skinner describes the private world as “part of the universe enclosed within the organism’s own skin....With respect to each individual, in other words, a small part of the universe is private. (italics in the original) We need not suppose that events which take place within an organism’s skin have special properties for that reason” (Skinner, 1953, p. 257.) Moore (2001, p. 237) adds, “(a) private events are behavioral in character, and (b) they can contribute to discriminative control over behavior.” More simply put, radical behaviorism eliminates “mind” and in its place substitutes “private behavior.” But, Skinner’s standing among psychologists is due more to the results of his research than to the theory behind it.

Long-term successes of Radical Behaviorism

Skinner deserves his position as the most eminent psychologist of the 20^th century (Haagbloom et al., 2002) because of his long-lasting contributions to the discipline. Of his many contributions, a few stand out above the others. Already mentioned above are the operant conditioning chamber and the cumulative recorder. Those two enabled the discovery of schedules of reinforcement, the partial reinforcement extinction effect, and shaping. Another long-term contribution was his desire to apply psychology toward the betterment of the world. Or to put it in radical behaviorist terms, to reshape the environment in such a way to improve nearly every aspect of human behavior. In this last respect, Skinner was very much an utopian who believed that psychology, properly conceived and applied, could improve the world.

Skinner first described four basic schedules of reinforcement in addition to the original one, continuous reinforcement, where a lab animal received a reinforcer every time it made the operant response. He termed the new ones intermittent schedules to distinguish them from continuous reinforcement. The intermittent schedules delivered reinforcers on the basis of time (interval schedules) or number of responses (ratio schedules). In addition, each type could be delivered reliably (fixed) or randomly (variable) leading to four different schedules: fixed interval (FI), variable interval (VI), fixed ratio (FR), and variable ratio (VR). Each schedule was associated with a consistently different pattern of responding that came from the schedule itself. Skinner (1953, p. 99) noted of behavior under intermittent schedules, “Usually, such behavior is remarkably stable and shows great resistance to extinction.” The four basic schedules displayed very different cumulative recordings as displayed in Figure 11.5. The steeper the recording is, the faster the response rate. FR and VR schedules can achieve high rates of responding while the VI schedule never does. Also, note the characteristic differences in the shapes of the curves. The FI schedule is scalloped because organisms slow down immediately after receiving a reinforcer and speed up just prior to its delivery. The FR schedule shows post reinforcement pauses after each reinforcer is delivered. Outside of the laboratory schedule effects are easily observed as well. Slot machines pay off following a variable ratio schedule and players continue to insert money and pull the handles for long periods. Remuneration for most jobs follows a fixed interval schedule (e.g., getting a paycheck once a week). Workers in those jobs work the hardest just prior to receiving their checks, but their work rates drop off dramatically afterwards. Wise managers, thus, pay their employees late on Friday afternoon. Some jobs, though, pay according to a fixed ratio schedule (piecework). Those workers achieve higher levels of production and earn more than workers paid on a fixed interval basis. Reinforcement schedules can exert powerful contingencies on behavior.

------Insert Figure 11.5 about here[cumulative recordings of intermittent schedules]-----

FYI: Partial Reinforcement Extinction Effect (PREE)-To me, one of Skinner’s most startling discoveries was the partial reinforcement extinction effect or PREE. It runs counter to commonsense and makes a wonderful rejoinder to those who argue that psychological research simply validates commonsense. The PREE is seen in organisms under intermittent reinforcement. Compared to organisms under continuous reinforcement those under intermittent reinforcement take much longer to extinguish, and as noted above, they also achieve higher response rates. If you have friends who doubt the value of psychological research, you might ask them the following question, “Will an organism work harder and longer when you give it a food reward every time it makes the correct response or when it gets a food reward every tenth time?” More often than not the psychologically naïve will select the first alternative. After they do, you can explain their answer and say why it is incorrect.

Shaping, was another of Skinner’s discoveries. He described operant conditioning as a process similar to a sculptor shaping a lump of clay. Operant responses, he argued, are not “discrete units of behavior” (Skinner, 1953, p. 91), rather they are the end products of process he called shaping. Here is how he described the shaping of a pigeon

Marginal Definition: shaping-the reinforcement of successive approximations of a final, desired response.

to peck at a particular location on the wall of its enclosure (p. 92):

To get the pigeon to peck the spot as quickly as possible we proceed as follows: We first give the bird food when it turns slightly in the direction of the spot from any part of the cage. This increases the frequency of such behavior. We then withhold reinforcement until a slight movement is made toward the spot. This again alters the general distribution of behavior without producing a new unit. We continue by reinforcing positions successively closer to the spot, then by reinforcing only when the head is moved slightly forward, and finally only when the beak actually makes contact with the spot. We may reach this final response in a remarkably short time. A hungry bird, well adapted to the situation and to the food tray, can usually be brought to respond in this way in two to three minutes.

The alternative to shaping, in this case waiting for the pigeon to peck a spot on the wall and then delivering a reinforcer, would take much longer. It would not occur if the pigeon never pecked the wall. In practice, shaping has proven to be a powerful way of molding new operants quickly.

---------------Insert Figure 11.6 about here[Skinner shaping a pigeon]---------------

Skinner’s utopian visions appear most prominently in his books Walden Two (1948) and Beyond Freedom and Dignity (1971). In the latter work, especially, he argues that society can be improved but only if people are willing to give up belief in free will and personal autonomy as causal factors. In their place, Skinner proposed that people could arrange environmental contingencies is such a way as to promote a better world. He understood the difficulties he would have in promoting his solution. Freedom and dignity were the last preserves of “autonomous man” and they blocked the path to a scientific understanding of how the environment could be changed in order to promote good behavior (Skinner, 1971, p. 25):

Freedom and dignity illustrate the difficulty. They are the possessions of the autonomous man of traditional theory, and they are essential to practices in which a person is held responsible for his conduct and given credit for his achievements. A scientific analysis shifts both the responsibility and the achievement to the environment. It also raises questions concerning “values.” Who will use a technology and to what ends? Until these issues are resolved, a technology of behavior will continue to be rejected, and with it possibly the only way to solve our problems.

In place of traditional views on causation (e.g., free will and personal autonomy) Skinner (1981) urged that science accept a new conception for the source of behavior. That conception was his triad of selection by consequences found at the levels of natural selection, operant conditioning, and culture. He concluded (p. 504), “So long as we cling to the view that a person is an initiating doer, actor, or causer of behavior, we shall probably continue to neglect the conditions which must be changed if we are to solve our problems.” Skinner’s hopes have yet to be realized. Moreover, while radical behaviorists continue to research and apply their results to practical situations, psychology itself has moved in another direction, away from radical behaviorism. The radical behaviorists, themselves, have explored that phenomenon.

Radical Behaviorism Today

Radical behaviorism and the rest of psychology are uneasy partners at best. On the one hand, all psychologists recognize Skinner as one of a small handful of eminent 20^th century researchers and theorists. But on the other hand, the research and practice of radical behaviorism and nearly all of the rest of psychology hardly ever overlap or affect each other. This situation was dramatically illustrated by Morris, Lazo, and Smith (2005) when they described how an earlier article (Morris, Lazo, & Smith, 2004) they had written about Skinner and how much of his research incorporated biology had been rejected by five non-behavior analytic journals. Ultimately, they published it in The Behavior Analyst, and then had to respond to inquiries about why they had published it there, in a place where the “readership was already aware of Skinner’s views and that the paper should have appeared in a journal whose readers had more to gain” (Morris, Lazo, & Smith, 2005, p. 169). Their reply was simple; their article had been rejected by five other generalist journals. They observered that behavior analysis had become isolated from the rest of psychology for a variety of reasons. In addition, Skinner’s views on what he termed the science of behavior are often unknown or distorted by mainstream psychology faculty and students. Of all of the neobehaviorist approaches only his remains vital today, but that vitality is only seen in a relatively small and remote corner of psychology’s garden. As Segal and Lachman (1972, pp. 53-54) note:

After World War II...major formal and theoretical advances outside psychology in finite mathematics, computer technology, information theory, and philosophy of science...gave rise to procedures and ideas applicable to formulations in competition with the behaviorist approaches. Problems within S-R behaviorism which were generally conceived to be empirically resolvable proved to be intractable. The strong neobehaviorist positions have weakened so considerably in the face of this competition that neobehaviorism can hardly be identified. Thus, the justification for the domination of psychology by neobehaviorism has eroded, as has the domination itself.