Burrhus Frederic Skinner: Theories and Models


Born in the small town of Susquehanna Pennsylvania, Burrhus Frederic Skinner became one of most renowned American psychologists of the twentieth century and his first book titled “The behavior of organisms (1938), proved to be a path breaking treatise on behaviorism (Fuller, 1995). During the next five decades, Skinner’s position and views were developed, criticized, evaluated and elaborated. He graduated in literature from Hamilton College and soon thereafter turned to writing (Fuller, 1995). But he did not find success as a writer. He then came across some articles by Bertrand Russell, which led him to study John B. Watson’s behaviorism, Jacques Loeb and Berman (Smith, 1994, 1994). He soon enrolled himself as a Ph.D. student at Harvard University for the autumn of 1928. It is interesting to note that he made the shift from literature to behavioral psychology without any intermediate course in psychology (Smith, 1994, 1994). He explained his passion for behaviorism saying that it appealed to him because he firmly believed that knowledge of human behavior can solve many of the problems facing humanity. Skinner worked on the ideas of Pavlov, Thorndike and Watson and provided new findings in the context of differentiation, generality and integration (Smith, 1994, 1994). He was endowed with the gift of thinking practically and technically.

Skinner’s basic views on Science, Psychology and Behavior

As Skinner did not have any kind of formal background in the field of psychology, he felt he could build his research programs from scratch and explore freely. He did not begin with a hypothesis that he conceptualized how to test. He simply used the resources available in the environment for his experiments. He chose rats to be his experimental subjects because he could afford them, occupied little space and could be submitted to experimental control of their routine of living. He also used departmental resources as his experimental apparatus. Skinner, in 1953, extended his findings from animal studies to a systematic treatment of human behavior in “Science and Human Behavior” (Demorest, 2005). Skinner had two basic assumptions regarding science: he assumed that science must not be made up of passive knowledge but rather active knowledge to deal effectively with the world (Demorest, 2005). And, in the context of the science of psychology, he argued that psychology must give up its past efforts to study the human mind and focus squarely on behavior. He contrasted the study of the mind as a “passive” kind of knowing, focusing on thoughts, needs, or emotions that occur to people, with the study of behavior as the study of what people actively do. Skinner first draws an explicit parallel between psychology’s study of human behavior and physics’ study of a rolling stone, and he ends by making the astonishing claim that attention to internal states is no more relevant to the former than it is to the latter (Demorest, 2005). He implied by this statement that the study of humans can proceed along the same lines as that of physical objects. Skinner believed that people could be understood only by studying their behavior and he assumed that human behavior like the rolling stone is caused by external forces and there are no inner causes. He did not accept the role of genetic factors in the development of behavior. To develop a science of psychology that focused on environmental influences Skinner sought to identify the laws by which the environment influences human behavior (Demorest, 2005).

Concept of Behaviorism

Behaviorism originated with the publication of John B. Watson’s 1913 “manifesto” in which Watson argued that to overcome the limitations imposed on psychology by the narrowness of structuralism and aimlessness of functional can be overcome only by redefining psychology as an “objective natural science” with behavior (rather than consciousness) as its primary subject matter. Thus, the true beginning of radical or contemporary behaviorism may be traced to the publication in 1938 of B. F. Skinner “The Behavior of Organisms: An Experimental Analysis”. Skinner was influenced heavily by the works of Watson. Watson, in his book “Behaviorism” (1924) had said that if he were given a dozen healthy infants, and allowed to raise them in a controlled environment, he can successfully train any random one among them to becoming any type of specialist – doctor, lawyer, artist or even a beggar or thief. This belief attracted Skinner a lot because this theory helped him avoid self blaming at his inability to become a successful writer. Moreover, Skinner liked the idea that it was possible to have control of one’s behavior. Even before he had taken a single course in psychology, Skinner had become a self-proclaimed champion of the behaviorist system (Demorest, 77) Skinner extended Watson’s mechanistic stimulus-response conception of behavior theory and established a sophisticated theoretical and experimental approach to the study of behavior which brought him name and fame (Todd, xxiii).

Skinner Box and Walden Two

Skinner extended his findings from the experiments to the psychology of all organisms from protozoa to human beings. In the laboratory, Skinner developed the ‘Skinner Box’, a small box-like apparatus under the experimenter’s control, which had the capability of representing all environments. With the use of the experimental method, the box and the white rat Skinner was able to create a database and a theoretical point of view. In his book “Science and human behavior” (1953), Skinner extended animal data by extrapolation to all aspects of human beings. The book dealt with six sections: the possibility of a science of human behavior; the analysis of behavior; the individual as a whole; the behavior of people in groups; controlling agencies and the control of human behavior (Smith, 1994). Skinner was open to consider all kinds of issues from all kinds of subjects. He took up the social angle shortly after the Second World War when he published Walden Two (1948) in which he discussed the issue of utopia, the good society (Smith, 1994). Though the book created some controversy initially, it was a huge commercial success and it gave Skinner, his first taste of success as a writer. In the mid-1940s, when his second child was born, Skinner turned his focus on the behavioral engineering task of improving the infant’s environment and the mother’s mental health by using an ‘air crib’ – which was described as a “baby in a box” (Smith, 1994, 4). Skinner created a controlled environment for the child within the box and proved that the baby could be raised within a controlled environment.

Basic principles of Skinner’s learning model

Skinner first proposes a distinction between two kinds of behavior, respondents and operants. Respondents are behaviors caused in a person due to a change or stimulus in the environment. For example, an eyeblink is a response to irritation in the eye. Operants, on the other hand, are not caused by environmental factors, but by the organisms to operate on the environment. Whether these acts get repeated depends on the environmental consequences. For example, a wink is an operant that, once enacted, will be more likely to recur in future if it results in a smile from the other being winked at, and less likely to recur if its consequence is a scowl from the other.

While the respondent such as an eyeblink is an involuntary act, the operant such as a wink is a voluntary act. However, this does not mean that operants are controllable and respondents are uncontrollable. Skinner holds that both operants and respondents are fully under the control of the environment and not of the organism; but the nature of control differs in the two cases. In the case of respondents, the environmental stimulus happens before the behavior and the respondent is common to all organisms in nature. For example, when there is irritation in the eye, the eye automatically blinks to protect the eye. This reflex action is common across all organisms in all situations. The difference in the case of operants is that the environmental stimulus occurs after the organism’s behavior, and the relationship between behavior and environmental consequence differs across organisms and situations. A wink can cause reaction for people but not for rats and moreover, it is not necessary for the wink to elicit a smile from a person all the time. Because of this variability, the environmental control of operants is less apparent than that of respondents.

Skinner argued that most of the behavior of adults is in the form of operant and therefore control of operant is an important area to be studied in the context of understanding human behavior. According to Skinner there are three major processes by which operants are controlled by their environmental consequences: reinforcement, extinction, and punishment. Reinforcement is the process by which a behavior is encouraged to happen more often. An operant behavior will increase in frequency if it is followed by the presentation of something favorable or by the removal of something unfavorable (Perkinson, 1984). Positive reinforcers are conditions that, when they follow behavior, increase the probability of that behavior being repeated. Food, praise, and so forth are usually positive reinforcers. Negative reinforcers are conditions, the removal of which will increase the probability of the behavior that removes them. Anything aversive to the organism is a negative reinforcer: pain, hunger, thirst, etc are negative reinforcers (Perkinson, 1984). Thus, in Skinner’s experiment, the rat pressed the lever more number of times when it was fed with a food pellet each time it pressed the lever. A behavior will decrease in frequency as a function of extinction or punishment. In extinction, the behavior is brought to a halt by stopping the reinforcing element. Skinner’s rat showed a decline in lever pressing when the food magazine jammed and stopped delivering food for it. In punishment, there is a decline in the frequency of a certain behavior and practically, it is enforced by presenting something unfavorable or by the removal of something favorable. When a child gets spanked for saying a dirty work, it will stop telling it. Though there are three methods of human behavior control – reinforcement, extinction and punishment, Skinner felt that punishment is the more commonly employed method of human control.

Based on the respondent and operant concepts, F. Skinner advocated two different principles of learning – respondent conditioning and operant conditioning (Perkinson, 1984). Respondent conditioning refers to the procedure that others call classical or Pavlovian conditioning, and operant conditioning refers to the procedure that others call instrumental conditioning (Perkinson, 1984). Skinner favored instrumental or operant conditioning in the context of education. He totally disapproved the use of punishment for control due to two main reasons: he did not believe punishment could be effective in the long run and secondly, punishment can have undesirable side effects in the form of negative emotions such as fear and rage. Thus, in the context of learning B.F. Skinner considers that positive reinforcement and avoidance of punishment are the key to success in learning. It is punishment or reward that determines whether a particular kind of behavior becomes habitual (Andrei, 2003). To be effective, reinforcement should be appropriate and immediate (Bucher and Manning, 2001). In Walden Two, Skinner said that learning is positively reinforced by natural consequences, teaching is empirically based and educational progress is graded by readiness of the students and not to which class or year he belongs.

Skinner views on teaching

Skinner in 1959 trained pigeons for being used as organic control mechanisms for guided missiles in war (Zimmerman and Schunk, 2003). He was able to train the pigeons to track silhouettes of ships and peck at the image, thereby triggering a flight response of the missile. Thus, it was now clearly evident that Skinner’s theory could be applied in the context of education. In his three volume autobiography, Skinner discussed his daughters’ educational experiences. Skinner found that the normal process of teaching was inadequate in two ways: the students were not informed whether their work was right or wrong immediately after the exam and secondly the students were made to progress at the same level despite varying levels of preparation or ability. He therefore built a “teaching machine”. Applying the concept of reinforcement, Skinner, began the teaching-machine movement, which was soon followed by programmed learning.

Technology of teaching

Skinner was able to observe keenly, and whenever he observed any problem or issue related to his theories, he was able to build technological equipment to solve the issue. He had an eye for ‘creativity’ and in one of his essays, ‘How to teach animals’, Skinner said that even a child’s toy or metal snapper which gives a high pitched sound can be converted into a reinforcer by using it in combination with food for the animal. The animal can be taught to do an act by using the sound along with the food (Smith, 1994, 5). The book “The technology of teaching” (1968) revolved around the problems in teaching and learning. In this book he discussed various aspects of school organization and administration. According to him the technology of teaching must be based on a framework of four elements: motivation, creativity, discipline and self control. By keeping a student motivated, self controlled and creative, Skinner felt teaching could be effective. Thus, the technology of teaching was basically educational psychology for teachers.

The educational psychology of teachers involves the scientific analysis of behavior and this in turn provides a practical framework for educational principles regarding the design of schools, equipment, textbooks, and classroom practices. Generally, the principles of learning consist of three variables: a situation or occasion that deduces behavior; the behavior itself; and the consequences of the behavior. In the context of education, the teacher must determine the behavior to be learned, must devise situations to evoke that behavior, and most importantly, must arrange contingencies of reinforcement.

Skinner explained his basic views on teaching by illustrating how he taught a pigeon to pace a figure eight. A hungry pigeon is placed in an enclosed space and it was conditioned to eat food from a food dispenser. This is the only conditioned act of the pigeon. In order to teach him to fly in figure eight, the demonstrator must reinforce any current response that would ultimately lead to the final pattern. He does this using reinforcement allowing the pigeon to learn it gradually. When a complete counterclockwise movement has been shaped, the clockwise turn is reinstated and, eventually, the pigeon makes both turns in succession and is reinforced. The whole pattern is then quickly repeated. Skinner says, though the teacher’s only contact with the pigeon is through the food dispenser, by identifying behavioral objectives and improvising a program of contingencies to reinforce that behavior gradually helps the pigeon approach the terminal behavior. According to Skinner, this method was known as shaping and could be used among human beings as well.

In his book, “The Technology of Teaching” Skinner suggests a number of techniques for various classroom tasks such as teaching writing, memorizing a poem, and teaching the meaning of words. According to Skinner, teaching involves modifying or shaping behavior. In all cases of teaching, it is expected that the teacher identifies the behavioral objectives, evokes the behavior, and arranges contingencies of reinforcement. Priming is a method whereby a teacher evokes behavior simply by giving the student verbal instructions or by presenting a model for the student to imitate or copy. Prompting is a form of priming in which the student is given a hint or partial answer to nudge him towards the correct answer. Reinforcers in the classroom can be tangible prizes such as candy, books, prizes etc. or intangibles like grades, honors, privileges, smiles, nods, pats on the back, and saying “right” or “correct”. In addition, there are the automatic reinforcements of being right and moving forward.

Teaching Machines

Skinner used the word “a teaching machine” to denote any device which can arrange contingencies of reinforcement (Skinner, 1965). In simpler words, it was a device for delivering programmed instruction or the hardware. Considering the fact that teaching is “the expediting of learning”, teaching machines are aimed at teaching rapidly, thoroughly and expeditiously a large part of the lessons (Zimmerman and Schunk, 2003). This minimizes wasted effort on the part of both student and teacher. Skinner produced such teaching technology and their design evolved throughout the 1950s. The designs ranged from equipment that drilled and tested course content such as manila envelopes with windows through which cards with questions and answers could slide, to those that shaped new behavior, such as covered disks that rotated to present questions, prompt responses, and display answers. In the case of covered disks, the design specifications included three terms: course content must be introduced from answers to questions about it, there must be provision for students to recall and construct their answers and not just recognize and select them; and finally, answers must be presented as the immediate consequence of student response. Any further design specifications were dictated by the means and ends of programmed instruction, for machines themselves do not teach. With the advent of new technology much more complicated teaching machines are now available. These new machines make use of an electronic computer and multimedia techniques (Andrei, 2003). However, the efficiency of the teaching machine depends on the quality of its program. Skinner introduced the programmed instruction as a novel teaching method.

Programmed Instruction

Programmed instruction was developed by B. F. Skinner (1968) as a means of including what was known at the time about learning from research in the laboratories – instruction could occur without the teacher being present. It is the task of the program to help him give the right answer and confirm his response. Programmed instruction was found to last over a longer period of time than teacher directed learning and provide greater mastery across a wide range of subjects and ages. It was delivered using teaching machines or in a programmed text format but more recently, it is in the form of computer-based instruction (Moran and Malott, 204).

Skinner suggested that the programmed instruction should be both structural and functional meaning. Structurally, instructional material is broken down into small steps and sequenced in “a plausible genetic order” – a logical sequence that allows the student to progress gradually till the end. But successive approximations alone are insufficient for teaching and it is important that each approximation or step is mastered before the next one is presented. This, Skinner recognized, was foreseen by Thorndike (1912): “If, by a miracle of mechanical ingenuity, a book could be so arranged that only to him who had done what was directed on page one would page two become visible, and so on, much that now requires personal instruction could be managed in print” (p. 175, as cited in Skinner, 1963). A teaching machine and its program constitute such a book.

Functionally, programmed instruction is based on the consequences and antecedents of responding. The consequences of responding refer to the response given by the programmed instruction model to the student. The consequences are the correct answers in each successive approximation to terminal performance, which act as reinforcers to move forward. Before reinforcement can be programmed, however, responding must occur first and this involves programming its antecedents, the techniques for which Skinner drew from Verbal Behavior (Skinner, 1957) – priming, prompting, and “vanishing.” When these techniques are systematically applied to subjects such as spelling, algebra, physics, neurology, etc in a sequence of successively mastered “frames”, the result is a “program” of instruction that teaches (Zimmerman and Schunk, 2003).

Programmed instruction deals with individualized pacing. Students progress according to their individual capabilities and there is no universal time duration for all students to learn a fixed amount of material (Zimmerman and Schunk, 2003). Successful programming is a very difficult task because if the student gives a wrong answer, it implies that the program has failed in its teaching aspect. The best part of programmed instruction is that it can be improvised over time through observing the pattern of student responses. A problem that is incorrectly answered by a number of students is obviously faulty and has to be rewritten or broken down into additional steps (Andrei, 2003). The principles of programmed instruction according to Skinner’s learning theory involve the following steps: material of instruction is carefully graded, presented as blocks of easy steps, response required from student, ensure that students make minimum number of mistakes, result and correct answer provided instantaneously and the program must be used on an individual basis by the student. There are two basic approaches to programmed instruction – the constructed-response program and the multi-choice program (Andrei, 2003). The constructed-response program requires the student to write an elaborate answer using full sentences and hence, in this approach, the student needs to have the ability of recalling. According to Skinner, emission of response is more effective in learning than simple recognition because it involves the learner being active. On the other hand, the multi-choice type of program requires the student to select one of a many alternate answers to a given question and tests the ability of the student to recognize, which is a passive activity. Moreover, structurally, the constructed response as promoted by Skinner’s programmed instruction is linear whereas the multiple-choice program is branching and intrinsic (Andrei, 2003). In the linear program the material is presented in a single ordered sequence and the student has to progress sequentially. Each correct answer allows the student to opt for the next item in the program and it is important that errors are kept minimal. The students must not only be made aware of his mistakes but he must also be provided with the correct answers. One of the main advantages of programmed instruction is that it explains why a response is right or wrong. As the program follows a fixed pattern of response, it is possible to find out the cause of errors and prepare appropriate explanations and remedial branch for insertion into the program at any point. Students who are unable to answer correctly may be forced to enter the remedial program before coming back to the regular program material.

Challenges in Programmed Instruction

Programming is not an easy thing as it involves difficult interactions among programmers, programs and students at three different levels – individual (learning), interpersonal (teaching) and cultural (educational). Skinner in 1954 realized that these practices were more art than science, even though his earlier experiments had provided a scientific basis to learning and teaching (Zimmerman and Schunk, 241)

Advantages of Programmed Instruction

Programmed instruction has its own advantages. It can do more than teach facts and simple skills. It teaches thinking. According to Skinner, thinking is behavior, whether in the form of paying attention, observing, making decisions, or solving problems. To teach thinking, as in the case of any other behavior, the teacher must first specify the behaviors to be learned, evoke these behaviors, and arrange for contingencies of reinforcement. In the case of problem solving, for example, Skinner points out there is a problem when some conditions will be reinforcing, but the person lacks a response that will produce it. He will solve the problem when he emits such a response. But solving a problem is more than emitting a response that is the solution. It is a matter of taking steps to make that response more probable. These steps are techniques, behaviors, which can be specified beforehand. If the problem is to say whether two things are the same or different, they may be placed next to each other to be compared, but if the problem is to confirm that they are different, they are kept separated. Likewise, similar things in classes are grouped together when they need to be treated in the same way. As with teaching anything else, a teacher can specify these behaviors, then take steps to evoke them, and arrange for contingencies to reinforce them. (Perkinson, 1984)

Skinner’s Darwinism

Generally behaviors are strengthened by the outcomes. When a hungry organism exhibits behavior that produces food, the behavior is reinforced by that consequence, and is, therefore, more likely to recur (Perkinson, 1984). Likewise behavior that reduces a potentially damaging condition, such as an extreme of temperature, is reinforced by the result of cooling and therefore is likely to be used again and again on similar occasions. Skinner held that growth of behavior, then, like the growth of the species, is a matter of adaptation to the environment. But such adaptation involves no purpose, or intent, or aim on the part of the organism. It is solely a matter of selection by the environment. This is known as Skinner’s Darwinism. When a hungry pigeon is put into a box, for example, it engages in exploratory trial behavior as it attempts to solve the problem of its hunger by pecking at different places each time. In the case of Skinner boxes, the pigeons must peck at the red disk to receive food. According to Perkinson (1984), the pigeon learns to do the desired thing not by reinforcement but by a method of trial and error elimination to solve the problem of hunger. This is a procedure of Darwinian selection. In the same way, a child learns to read, write, spell, be courteous, tie his shoelaces, or whatever he learns: by trial-and-error elimination. The environment, or the teacher, or his parents do not reinforce his behavior; they only provide critical feedback (Perkinson, 1984).

Skinner’s Transmission Theory of Education

Departing from his Darwinist views, Skinner has constructed the transmission theory of education. As a transmission theorist, Skinner views knowledge as the personal possession of some subject. Yet he does not view the learner as a receptor of knowledge, as do most other transmission theorists. According to him, people create knowledge insofar as they emit behavior. The organism is the source of knowledge. Thus, Skinner views the learner as an active creator of knowledge in the context of the transmission theory of education. However, this implies that education must be seen as a process of complete manipulation and total control. The teacher must determine what behaviors the student should learn, construct a situation that educes these behaviors from the student, and arrange an environment that reinforces the desired behaviors. This emphasis on control has lead to severe opposition to the behaviorist position. Though Skinner admits there is opposition, he insists that without any chance of choice, human behavior is always controlled. If teachers, parents, adults refuse to control the behavior of the young, refuse to see to it that they do develop proper behaviors, then the youngsters are left to “adventitious control by contingencies of reinforcement” – resulting in dangerous behaviors (Perkinson, 1984). Thus, in Skinner view, even though teachers do not like to see themselves as controllers of behavior, they must recognize they are indeed entrusted with the task of controlling behavior of students.

Criticism of Skinner

Skinner’s research has been criticized for treating human knowledge and thought in “mechanistic” terms, reducing knowledge to responses and thinking to facts. To this he had three explanations: he held that this kind of analyzes could explain many subject matters; secondly, knowledge and thought are descriptive concepts and knowing how to solve a mathematical problem is just a behavioral act of great complexity; third, he felt that independent of course content, programmed instruction can indeed teach thinking and promote self study (Zimmerman and Schunk, 2003). Another set of criticisms was that students would become dependent on teaching machines, individuality would be suppressed, and grades would be meaningless. For this, Skinner says that there are some advantages of teaching machines that make it all worthwhile. They can be used independent of classroom settings and where teachers are not available. As lessons are self-paced it can be customized to the student’s intellectual capabilities. Grades would reflect differences within students in the amount of the material they mastered. Teaching machines were also considered a threat to the teacher in the classroom. Skinner explained that teaching machines only eliminate tiresome work such as grading and disciplinary duties. There would still be classroom contact and responsibilities, Teachers would benefit from the support (Zimmerman and Schunk, 2003).

Skinner’s theories were also criticized. Skinner’s determinism raises a paradox. If Skinner says that all human conduct is the result of conditioning by the environment, his verbal behavior must also be the result of Skinner’s own conditioning by the environment. Someone else may say that human conduct is not the result of conditioning by the environment and his verbal behavior must also be accepted. If behaviorism is true, it is impossible to consider any argument in its support (Perkinson, 1984). Another criticism arises in Skinner’s explanation as to how behavior is determined by the environment. He says that a response that is reinforced upon a particular occasion is most likely to occur on a similar occasion. But any particular occasion is relevant only to a particular someone. This is because all repetition, all similarity, is a product of expectation, which depends from individual to individual (Perkinson, 1984). These contradictions seem to suggest that Skinner’s determinism is false and human conduct is not determined, and not always and necessarily controlled. But it can be controlled if necessary and in fact, Skinner’s work demonstrates that it is possible to create educational environments where human conduct is controlled


Skinner’s learning theory holds that behavior is not under the control of the individual psyche but rather under the control of the environment. By studying contingencies of reinforcement and punishment it is possible to reliably predict and control behavior. Skinner’s finding is that behavior is increased through reinforcement and decreased through punishment or extinction. This creates an image of people acting as physical objects in motion, susceptible to lawful external forces. Skinner’s learning theory is powerful in its simplicity. By asserting confidently that the inner world can be ignored Skinner was able to expose the logical legality of relationships between behavior and the environment (Demorest, 2005). This has serious and valuable meaning in the educational context, particularly in the realm of teaching, learning and providing the right environment.


Andrei, Laura (2003). Teaching Machines and Programmed Instruction.

Bucher, T. Katherine and Manning, Lee (2001). Exploring the Foundations of Middle School Classroom Management: The Theoretical Contributions of B. F. Skinner, Fritz Redl and William Wattenberg, William Glasser, and Thomas Gordon All Have Particular Relevance for Middle School Educators. Childhood Education, 78 (2), 2001.

Fuller, Ray (1995). Seven Pioneers of Psychology: Behaviour and Mind. Routledge Publishers, 1995.

Moran, J. Daniel and Malott, W. Richard (2004). Evidence-based Educational Method. Academic Press, 2004.

Perkinson, J. Henry (1984). A Reinterpretation of Twentieth-Century Educational. Greenwood Press, Westport, CT, 1984.

Skinner, B. F. (1938). The Behavior of Organisms. AppletonCentury-Crofts, New York, 1938.

Skinner, B. F. (1953). Science and Human Behavior. Free Press, New York, 1953.

Skinner, B. F. (1954). The science of learning and the art of teaching. Harvard Educational Review, 24, 86–97.

Skinner, B. F. (1957). Verbal behavior. Appleton-Century-Crofts, New York, 1957.

Skinner, B. F. (1958). Teaching machines. Science, 128, 969–977, Appleton-Century-Crofts, New York, 1958.

Skinner, B. F. (1962). Walden Two. Macmillan Publishers, New York, 1962.

Skinner, B. F. (1965). The technology of teaching. Proceedings of the Royal Society, Series B, 162, 427–443.

Smith, M. Louis (1999). B.F. skinner. Prospects: Quarterly Review of Comparative Education, UNESCO, Paris, XXIV (3/4), 1994, p. 519-32. Web.

Zimmerman, J. Barry and Schunk, H. Dale (2003). Educational Psychology: A Century of Contributions. Lawrence Erlbaum Associates, Mahwah, NJ, 2003.

Find out the price of your paper