Behaviorism

A BRIEF HISTORICAL OVERVIEW

PSYCHOLOGICAL BEHAVIORISM

OBJECTIONS TO BEHAVIORISM

CONCLUSION

BIBLIOGRAPHY

Behaviorism is a twentieth-century term, made popular by the psychologist John Watson (1878–1958) in 1913. Although Watson introduced psychological behaviorism, there is also a version called philosophical behaviorism.

Psychological behaviorism is the view that psychology should study the behavior of individual organisms. Psychology should be defined not as the study of the mind and internal mental processes via introspection, but as the science of behavior. The most famous proponents of psychological behaviorism were John Watson and B. F. Skinner (1904–1990). Other notable behaviorists were Edwin Guthrie (1886–1959), Edward Tolman (1886–1959), Clark Hull (1884–1952), and Kenneth Spence (1907–1967).

Philosophical behaviorism, by contrast, is a research program advanced primarily by philosophers of the twentieth century. This school is much more difficult to characterize, but in general, it is concerned with the philosophy of mind, the meaning of mentalistic terms, how we learn this meaning, and how we know when to use these terms. Important philosophical behaviorists include Bertrand Russell (1872–1970), Gilbert Ryle (1900–1976), Ludwig Wittgenstein (1889–1951), Rudolf Carnap (1891–1970), Otto Neurath (1882–1945), Carl Hempel (1905–1997), and W. V. O. Quine (1908–2000). Other philosophers such as Daniel Dennett (b. 1942), Wilfrid Sellars (1912–1989), Donald Davidson (1917–2003), and Richard Rorty (b. 1931) have behavioristic sympathies to varying degrees.

Besides these two generic versions of behaviorism, there are several subvarieties (see Kitchener 1999; Zuriff 1985). Eliminative behaviorism is the denial that there are any mental states at all; there is just behavior. Methodological behaviorism is the view that it does not matter whether there is a mind or not; psychologists should just study behavior. Logical behaviorism (also called analytic behaviorism or semantic behaviorism ) is the view that all mentalistic terms or concepts can be defined or translated into behavioral terms or concepts. Epistemological behaviorism and evidential behaviorism hold roughly the view that the only way to know about a mental state is by observing behavior.

A BRIEF HISTORICAL OVERVIEW

It should be noted that in the intellectual history of western culture there have been individuals who held views very similar to theories supported by one or both of these movements, even though they did not use the term behaviorism ; others have championed views that may not be characterized as “behavioristic,” but which have had a strong impact on behavioristic ways of thinking (see Peters 1973–1974; Harrell and Harrison 1938). The writings of Aristotle (384 bce-322 bce), in particular his De Anima, his account of practical rationality in the Nicomachean Ethics, and his scientific work on animals (De Motu Animal ), contain ideas that were assimilated by later behaviorists. Likewise, the writings of the Stoics and the Skeptics contain several theoretical accounts that are sympathetic to a general behavioristic approach, especially their views about animal cognition.

Several seventeenth- and eighteenth-century works inspired behavioristic followers, including Thomas Hobbes’s generally mechanistic account of the mind, The Leviathan (1651), René Descartes’s 1637 account of animal behavior, Discourse on Method, and the writings of several individuals who belonged to the French Encyclopedists tradition of the Enlightenment, such as Julien de La Mettrie’s Man a Machine (1748), Pierre Cabanis’s On the Relations between the Physical and the Moral Aspects of Man (1802), and Baron d’Holbach’s The System of Nature (1770), among others.

The Cartesian Tradition A major philosophical issue emerging in the seventeenth and eighteenth centuries concerned the question of the nature of the human mind and the animal mind: Is it possible to provide a mechanistic, materialistic, and deterministic account of the human mind, or must one appeal to principles that are quite different from those used in modern physics? Descartes argued that the human mind is made of a substance different from any found in the natural world, one that operates by principles at odds with the ordinary causal processes of inorganic matter. Although humans possess this special kind of spiritual being, animals do not; they are, quite simply, machines that operate by ordinary “matter in motion” (Descartes 1637). Humans are radically different from such animals because the human mind is made of a quite different substance that is not observable by ordinary naturalistic methods; however, humans have a kind of special access to their own minds, found by means of internal reflection or introspection. None of this was true of animals, all of whose behavior can be explained mechanistically in terms of simple mechanical principles (see Rosenfeld 1941).

The question that arose, therefore, was this: If Descartes was correct about his animal psychology, was he also correct about human psychology? Do we need to appeal to a special nonmaterial substance to explain the behavior of humans, or can all of their behavior be explained in the same ways we explain animal behavior? Although Descartes’s answer was widely accepted, there were a few individuals who argued that humans are no different from animals, and hence if animal behavior can be explained along naturalistic lines—by observing their behavior and trying to explain it by deterministic laws of matter in motion—the same is true of humans. This was the view of some eighteenth-century thinkers who championed a purely naturalistic, materialistic, deterministic, and mechanistic account of humans. They were the forefathers of mainstream psychological behaviorism.

The nineteenth century produced philosophers and scientists who, in one form or another, contributed ideas that were fuel for the behaviorists’ fire. An example are the post-Kantian German idealistic philosophers, many of whom stressed the importance of praxis, or human action. These ideas in turn strongly influenced members of the philosophical/psychological school of pragmatism, including Charles Sanders Peirce (1839–1914), William James (1842–1910), and John Dewey (1859–1952). These pragmatists were concerned with understanding and providing an account of humans and animals that focused on their action—something that organisms did, something they tried to accomplish as they interacted in their physical and social environment. Strongly influenced by the Darwinian revolution, the pragmatists employed a Darwinian model of organisms adapting to their environments to understand action. Such an approach at once stressed the problem-solving nature of human and animal mentality and the assumption that everything that exists must be understood in a “functional” way—that is, how entities such as ideas are useful in an organism’s struggle to survive in its environment. All intelligence was to be explained in this way, as an “instrument of action.”

Although Sigmund Freud was no behaviorist, he did aid the behaviorist cause by challenging the reigning Cartesian model of the mind that maintained that humans had an immediate and privileged access to the inner workings of their minds that employed a first-person rather than a third-person perspective on the mind, and that tended to draw a sharp distinction between the human mind and the animal mind. Freud argued that the mind is not transparent to our internal gaze because most of our mental activity is going on below the surface at the level of the unconscious (Freud 1900). If this is correct, then the method of psychology cannot be assumed to be introspective. This opened the way to alternative methods of psychological investigation.

The work of Ivan Pavlov on the conditioned reflexes of dogs ([1927] 1960), as well as the work of other Russian physiological scientists, provided behaviorists with scientific accounts of behavior. Behavior occurs, persists, and changes as a result of classical conditioning : An original stimulus elicits some response; another stimulus is subsequently paired with the original stimulus, thereby acquiring the power to elicit the response. This version of S-R psychology is the paradigm for at least early behaviorism, providing an explanation of behavior. The other kind of learning employed by behaviorists was instrumental conditioning (operant conditioning, trial and error learning), first introduced in 1898 by Edward Thorndike (1874–1949). In instrumental conditioning, a response is learned because it is reinforced by a stimulus—the reward—where the response is instrumental in obtaining the reward. Classical and instrumental learning promised to explain all of behavior. None of this seemed to require private internal workings of a special kind of substance. Psychology could take its place among the objective natural sciences.

PSYCHOLOGICAL BEHAVIORISM

In psychology, behaviorism began with John Watson, who coined the term behaviorism and set forth its initial premises in his seminal article “Psychology as the Behaviorist Views It” (1913). Behaviorism, Watson suggested, should be considered an objective, natural science, one that studies the public, observable behavior of organisms. Rejecting the method of introspection practiced by his predecessors, Watson suggested a different method to be used by psychologists: Study the observable behavior of others, and to explain it, given the stimulus, predict the response; given the response, predict the stimulus. The aim of psychology, therefore, was the prediction and control of behavior. What then of the mind, that special substance that Descartes claimed was the special province of humans? Watson gave several different answers over the course of his career, including eliminative behaviorism, methodological behaviorism, and, later, the view that the mind exists but is the same as behavior. In short, Watson’s argument was this: Humans and animals are not radically different from each other, and since the behavior of animals can be explained without appealing to consciousness, the behavior of humans can be explained without appealing to consciousness, too. With the rise of the cognitive sciences in the 1960s, this conclusion was denied, and so was the claim that the behavior of animals can be explained without appealing to consciousness.

The key question is, what did Watson mean by “behavior”? Was it a mechanical physical movement of the body or something more complex—the intentional, purposive action of a rational agent? If the latter, then how can a purely mechanistic science account for it? This perplexing question remained at the center of discussion for decades. Doubts about a mechanistic approach gave impetus to versions of purposive behaviorism found in the writings of William McDougall (1912), Edwin Holt (1915), and E. C. Tolman (1932). Indeed, McDougall and Holt had been proposing a kind of teleological behaviorism before Watson had appeared on the scene.

We can divide the history of psychological behaviorism into several periods: (1) classical behaviorism, (2) neobehaviorism, (3) operant behaviorism, and (4) contemporary behaviorism. The first period (1912–1930) introduced the theory of behaviorism championed by John Watson and several other early advocates of behaviorism, including Max Meyer, Albert Weiss, Walter Hunter, and Karl Lashley. These behavioristic accounts were, by and large, naive, sketchy, and inadequate, but they set forth the general program of psychological behaviorism.

The second period (1930–1950) was the era of neobehaviorism, so called because its philosophical underpinnings were somewhat different from its predecessors. Neobehaviorism was wedded to classical learning theory (see Koch 1959), and neobehaviorists were concerned with what form an adequate theory of learning should take. The main figures were Edwin Guthrie, Edward Tolman, Clark Hull, B. F. Skinner, and Kenneth Spence. All of these individuals spent a great deal of time laying out the philosophical bases of their respective kinds of behaviorism, and in doing so, they borrowed heavily from the school of logical positivism, which was influential at the time (but see Smith 1986). This resulted in an emphasis on the importance of operational definitions, a preference for a hypothetico-deductive model of theory construction, and a focus on issues about intervening variables versus hypothetical constructs, and the admissibility of neurological speculation. This move toward postulating internal mediating responses continued with later Hullian neobehaviorists such as Charles Osgood, Neal Miller, O. H. Mowrer, Frank Logan, and others.

The last two phases of behaviorism are more difficult to characterize. Skinner’s version of behaviorism—operant behaviorism—is markedly different from most of the other neobehaviorists, and yet he is perhaps the best-known behaviorist. Indeed, after the demise of Hullian learning theory in the 1960s, the main thrust of the movement switched to Skinner’s distinctive version of behaviorism.

Denying he was an S-R psychologist, Skinner championed an operant account of learning, in which a response that occurs is reinforced and its frequency is increased (1938). The response—for example, a bar press or a key peck—is not elicited by any known stimulus, but once it has occurred, its rate of response can be changed by various kinds of reinforcement schedules. The response can also be brought under experimental control when it occurs in the presence of a discriminative stimulus (e.g., light). Such a relationship—discriminative stimulus, response, reinforcement—is sometimes called a contingency of reinforcement, and it holds a central place in Skinner’s brand of behaviorism. Skinner himself characterized his behaviorism as a “radical behaviorism” because rather than ignoring what is going on inside the organism, it insists that such events are still behavior (1974). However, such behavior still is caused by environmental variables.

Skinnerian behaviorism was the dominant version of behaviorism in the 1970s, and Skinner extended his approach to consider more and more complex behavior, including thought processes and language. His 1957 book Verbal Behavior, an example of this extrapolation, was reviewed by the linguist Noam Chomsky, who subjected it to devastating criticism (Chomsky 1959). Skinner declined to respond to Chomsky, and many individuals took this as a sign of the demise of behaviorism. This was not completely true, as can be seen in the current era of behaviorism, which features teleological behaviorism, interbehaviorism, empirical behaviorism, and so on (see O’Donohue and Kitchener 1999). Although behaviorism does not have the hegemony it once did, it continues to exist, but is restricted to pockets of research. Indeed, there are several scientific journals devoted to behaviorism, including the Experimental Analysis of Behavior and Behavior and Philosophy.

Philosophical Behaviorism Although psychological behaviorism can be described relatively clearly, philosophical behaviorism cannot. Fundamentally, a philosophical behaviorist is one who has a particular theory of the philosophical nature of the mind. All philosophical behaviorists are opposed to the Cartesian theory of mind: that the mind is a special kind of nonphysical substance that is essentially private, and introspection is the only or primary way of knowing about the contents of the mind, such that the individual has a privileged access to his mind. One or more of these tenets is denied by the philosophical behaviorist, who believes that there is nothing necessarily hidden about the mind: It is not essentially private, not made of a special substance, not known by any special method, and there is no privileged access to the mind.

In effect, the philosophical behaviorist claims that the mind is essentially something public, exemplified in one’s actions in the world, and that mentalistic properties are those displayed in certain kinds of public behavior. Such a view was championed by Bertrand Russell (1921, 1927; see Kitchener 2004). But what particularly distinguishes twentieth-century philosophical behaviorism is its commitment to semantic behaviorism, the view that philosophy is concerned with the analysis of the meaning of mentalistic terms, concepts, and representations. This “linguistic turn” in philosophy (Rorty 1967) means that instead of talking about the nature of the mind as an object in the world, philosophers should be concerned with our linguistic representations of the mind. This type of philosophical behaviorism is called logical (analytic, conceptual) behaviorism. Philosophical behaviorism, therefore, is different from psychological behaviorism.

Ludwig Wittgenstein is sometimes called a behaviorist, largely because he was critical of the Cartesian model of the mind, especially its assumption that the meaning of a mentalistic term must be given in terms of one’s private sensations or states of consciousness. Such an account would amount to a private language because only the individual can know the meaning of a mentalistic term, an item of his necessarily private experience. Private languages are not possible according to Wittgenstein, because any language must (initially) be a public language; the meaning of mentalistic terms must be intersubjective and public (1953). In order to use a word correctly, Wittgenstein claimed, there must be public criteria for its correct employment. Most individuals insist that Wittgenstein’s kind of behaviorism is radically different from the psychological behaviorism of Watson and Hull. Whether it is fundamentally different from Skinner’s behaviorism is still an open question.

Gilbert Ryle is also sometimes characterized as an analytic or logical behaviorist. Also rejecting the Cartesian conception of the mind, Ryle showed that mentalistic terms have to have public criteria for their correct use, and hence that mentalistic terms and states are not essentially private to the individual, but must be understood (largely) as complex behavioral dispositions, or actions (and tendencies to act) in certain kinds of physical and social situations (1949). According to Ryle, therefore, mentalistic terms are to be understood in the same way we understand the meaning of, for example, the term punctual : An individual is punctual if she shows up to class on time, regularly meets her appointments, and so on. Ryle had strong reservations about calling his views “behavioristic,” largely because he thought behaviorism was committed to a mechanistic account of bodily movements and this was certainly not what behavior (or better, action) was.

As Ryle was influenced by Wittgenstein, so were other philosophical behaviorists. Rudolf Carnap and Carl Hempel were members of the group of philosophers known as logical positivists. According to a fundamental principle of logical positivism, the meaning of a statement consists of its method of verification. The meaning of a mentalistic term must be verifiable to be meaningful, and in principle, its meaning consists in how one verifies it by means of empirical observation. For example, the statement “Paul has a toothache” is (approximately) equivalent in meaning to the procedures one uses to verify that Paul has a toothache. Although this might consist in observing Paul’s physical behavior, it might also consist in observing the state of Paul’s tooth. Hence, for logical positivists, analytic behaviorism merged into the identity theory of mind and central state materialism—the view that mental states are central states of the brain. It remains unclear, therefore, to what extent they should be called “logical behaviorists”; certainly their version of logical behaviorism was quite different from Wittgenstein’s and Ryle’s.

The last notable philosophical behaviorist was Willard Quine, who was strongly influenced by Carnap (and Wittgenstein); nevertheless, his views are not easily assimilated with theirs. His views about meaning (and hence the meaning of mentalistic terms) were verificationist in spirit (because he was an epistemological behaviorist), but he did not share certain of Carnap’s views about how to give a behavioral translation of mental terms. It cannot be done atomistically, but only holistically: One cannot give the meaning of single mentalistic term by giving observational conditions for its use. Indeed, Quine was suspicious of the very notion of “meaning” because such things, if they do exist, would be difficult to reconcile with naturalism and physicalism, and therefore the meaning of a mentalistic term cannot be equivalent to some item of behavior. Quine was also skeptical of the very possibility of verifying a statement by means of a set of observations; scientific observation is a much more theoretical affair than this. Nevertheless, Quine insisted that any science is committed to the observation of behavior (epistemological behaviorism, evidential behaviorism), and hence that mentalistic terms are, in some sense, equivalent to behavior. This is, in part, due to the public nature of language (Quine 1960). We obviously do learn what words mean in the process of learning a language, but all of this occurs in the public arena. We are taught how to use words by our linguistic community: In the presence of a public object such as snow, we learn (by principles such as those indicated by Skinner) to utter the word snow. Hence, Quine’s behaviorism is sometimes called a linguistic behaviorism because he insisted that all we have to go on when we teach and learn a language is the public behavior of individuals. This is closely tied to the importance of empirical observation and verification. Furthermore, Quine was committed to semantic behaviorism, the view that the meaning of words is necessarily tied to (or consists of) public behavior. Meanings are, therefore, not “in the mind.” This is a close cousin to the logical behaviorism of earlier philosophers.

With the rise of computer science and artificial intelligence in the 1960s, an interesting question arose concerning how one could decide if a machine such as a computer was intelligent or not (i.e., whether it “had a mind”). Alan Turing proposed a test—the “Turing test”—for deciding this question (Turing 1950). Basically, the Turing test holds that if you cannot distinguish a computer from a human in terms of its behavior, for example by asking them both questions and reading their answers, then because the human is intelligent, it would be difficult to deny that the machine is intelligent too.

The Turing test raises the issue of behaviorism once more, this time in the context of computers: Is it the actual behavior of the computer that is decisive in ascribing intelligence to it, or are the internal workings of the computer (e.g., using a lookup table) important? Those who answer yes to the latter question might be considered mentalists rather than behaviorists (Block 1981). There is reason to believe that Turing himself thought the internal processing of the computer were important, something most behaviorists have never really denied.

OBJECTIONS TO BEHAVIORISM

Psychological behaviorism and philosophical behaviorism have been criticized since the beginning of the twentieth century.

Objection: Behaviorism Ignores or Denies Consciousness Critics charge that because the behaviorist focuses on behavior—and this means external behavior—he or she ignores or dismisses the private internal realm of consciousness.

Let us assume that consciousness does exist, that individuals are aware of their internal mental thoughts and sensations. The methodological behaviorist argues that this realm can be ignored (from a scientific point of view) by simply refusing to consider it. Radical behaviorists argue that behaviorism does not have to ignore this realm; instead, one can simply treat consciousness as internal behavior not unlike the behavior of one’s stomach when it digests food. Or, a behaviorist might reply that consciousness is not actual occurrent internal behavior, but rather a behavioral disposition. This is what we ordinarily mean when we say things such as, for example, “the cat is awake and thinking about the mouse.”

One property of consciousness that it is particularly difficult for the behaviorist to accommodate are qualia —the internal “feel” of certain mental states or events, like the taste of chocolate or the feeling of a sharp pain. A related problem is how a behaviorist can handle images, for example, the image I have of my morning breakfast.

Objection: Behaviorist Explanations Are Inadequate Most behaviorists take behavior as that which needs to be explained—why it occurs, what its form consists of, why it ceases, and so on. But what provides the explanation of such behavior? The standard answer is that stimuli—external stimuli—provide explanations, together with psychological principles concerning the relation of such stimuli to responses. But according to the critic, it remains doubtful that external stimuli can provide such all-encompassing explanations. Instead, one must refer to certain kinds of internal states—typically cognitive states—to explain the behavior.

A very sketchy behaviorist reply would be that all explanatory internal states—including all “cognitive” states—can be explained in terms of the ordinary concepts of stimulus and response, as long as these terms are suitably modified. This typically has taken the form of saying that there are internal states occurring between the external stimulus and the external response but that these internal states are understood to be internal stimuli and internal responses; for example, according to Hull, internal states might be fractional anticipatory goal responses together with sensory feedback from them. These internal mediating mechanisms are not popular by contemporary cognitive standards, but if behaviorism is to be a viable research program, it must clearly postulate such an internal mechanism or something analogous. Whether these behavioristic models are sufficiently cognitive or representational remains an open question.

Objection: The Behaviorist Concept of Behavior Is Inadequate According to one popular argument (Hamlyn 1953), the behaviorist sees ordinary behavior as a mechanistic, physical response, like the movement of an arm. But this is an inadequate conception of human behavior, which is better thought of as an action, such as waving, signaling, flirting, or gesturing. The behaviorist cannot handle this kind of conception because actions are not mechanistic but rather intentional, teleological, rule-governed, governed by social norms, and so on, and these are incompatible with the behavioristic program.

The standard behaviorist reply is to deny the distinction between movements and actions and/or to argue that the behaviorist has always been interested in actions (Kitchener 1977), and that such a concept is consistent with a causal account.

Objection: The Behaviorist Cannot Adequately “Analyze” or Define a Single Mentalistic Term by Means of a Set of Behaviors Logical behaviorists attempted to translate a mentalistic term such as belief into a corresponding set of behaviors, for example, a verbal response. But such a translation is only plausible if we assume other mental states in our account, for example, other beliefs, desires, and so on. Hence we have not gotten rid of mentalistic terms (Chisholm 1957; Geach 1957) because there is no term-by-term reduction or elimination.

This objection carries little weight because logical behaviorists such as Carnap and Hempel very early in their careers gave up such a term-by-term approach in favor of a more holistic, theoretical approach, and this commands a central place in Quine’s holistic behaviorism.

Objection: The Spartan Objection and the Dramaturgical Objection A mental state, such as pain, is not equivalent to a set of public behaviors because it is possible for one to be stoic about pain: I might be in intense pain but never show it because, say, it is not “macho” to show pain. Likewise, I might manifest pain behavior but not really be in pain, as when I simulate pain as an actor in a play. Hence pain behavior is neither sufficient nor necessary for being in pain (Putnam 1975).

Both of these objections assume a very naive, “peripheral” behaviorism in which the behavior in question is publicly observable. It is necessarily restrictive because behaviorists can hold more sophisticated forms involving “internal” (covert) behavior along with the inclusion of behavioral “dispositions.” Secondly, the behaviorist has insisted that one learns the meaning of the term pain and to use the word correctly only in the context of public behavior, a view shared by Wittgenstein, Carnap, Quine, Sellars, and Skinner. There must be public criteria for the correct use of pain. So originally a certain kind of behaviorism must be correct; later, we may learn how to suppress such behavior and to internalize it. The basis of this claim concerns the learning of language and is based on Wittgenstein’s arguments against a private language, or on arguments similar to his.

CONCLUSION

Few individuals would claim that behaviorism today enjoys the popularity it once had. Indeed, many (or most) argue that behaviorism is dead—both in psychology and in philosophy. The claim is easier to make with respect to psychology, particularly in the aftermath of the cognitive revolution. Nevertheless, the reports of the death of behaviorism are somewhat exaggerated. Not only are there viable and interesting research programs that are behavioristic in name, there are signs that even in cognitive science and cognitive psychology there is a reemergence of behaviorism, for example, in connectionism (neural nets), robotics, and dynamic systems theory. In fact, according to some, it remains unclear how cognitive psychology differs from behaviorism, since most behaviorists have also been concerned with central cognitive states. Still, psychological behaviorism is currently a minor opinion.

In philosophy the matter is somewhat different. This is because of the centrality of language learning in analytic philosophy, which seems to demand something like a rule-following conception that presupposes a public or social conception of behavior. This view is shared by those sympathetic to Ryle, Wittgenstein, or Quine. The logical behaviorism of Carnap and Hempel is passé because it was abandoned early in favor of a central state theory of mind. But although psychological behaviorism may have seen its day, philosophical behavior, in one form or another, still claims the strong allegiance of many philosophers (depending on how one characterizes behaviorism ).

BIBLIOGRAPHY

Baum, William M. 1994. Understanding Behaviorism: Science, Behavior, and Culture. New York: Harper.

Block, Ned. 1981. Psychologism and Behaviorism. The Philosophical Review 90: 5–43.

Boakes, Robert A. 1984. From Darwin to Behaviorism. Cambridge, U.K.: Cambridge University Press.

Cabanis, Pierre J. G. [1802] 1980. On the Relations between the Physical and the Moral Aspects of Man. Trans. Margaret Duggan Saidi. Baltimore, MD: Johns Hopkins University Press.

Carnap, Rudolf. [1932] 1959. Psychology in Physical Language. Trans. G. Schick. In Logical Positivism, ed. Alfred Jules Ayer, 165–198. New York: Free Press.

Chomsky, Noam. 1959. Review of Verbal Behavior by B. F. Skinner. Language 35: 26–58.

Chisholm, Roderick. 1957. Perceiving. Ithaca, NY: Cornell University Press.

Davidson, Donald. 1963. Actions, Reasons, and Causes. Journal of Philosophy 60 (23): 685–700.

Descartes, René. [1637] 1984. Discourse on Method. Trans. John Cottingham, et al. In The Philosophical Writings of Descartes, vol. 1, 109–176. New York: Cambridge University Press.

Descartes, René. [1642] 1984. Meditations on First Philosophy. Trans. John Cottingham, et al. In The Philosophical Writings of Descartes, vol. 2, 1–62. New York: Cambridge University Press.

D’Holbach, Paul-Henri Thiry. [1770] 1970. The System of Nature. Trans. H. D. Robinson. New York: B. Franklin.

Freud, Sigmund. [1900] 1965. The Interpretation of Dreams. Trans. James Strachey. New York: Basic Books.

Geach, Peter. 1957. Mental Acts: Their Content and Their Objects. London: Routledge and Kegan Paul.

Hamlyn, D. W. 1953. Behaviour. Philosophy 28: 132–145.

Harrell, W., and R. Harrison. 1938. The Rise and Fall of Behaviorism. The Journal of General Psychology 18: 367–421.

Hayes, Linda J., and Patrick Ghezzi, eds. 1997. Investigations in Behavioral Epistemology. Reno, NV: Context Press.

Hempel, Carl. 1949. The Logical Analysis of Psychology. In Readings in Philosophical Analysis, eds. Herbert Feigl and Wilfrid Sellars, 373–384. New York: Appleton-Century-Crofts.

Hobbes, Thomas. [1651] 1994. The Leviathan. Indianapolis, IN: Hackett.

Holt, Edwin. 1915. The Freudian Wish and Its Place in Ethics. New York: Holt.

Hull, Clark. 1943. Principles of Behavior. New York: Appleton-Century-Crofts.

Hunter, Walter. 1919. Human Behavior. Chicago: University of Chicago Press.

Kitchener, Richard F. 1977. Behavior and Behaviorism. Behaviorism 5: 11–72.

Kitchener, Richard F. 1999. Logical Behaviorism. In Handbook of Behaviorism, eds. W. O’Donohue and Richard Kitchener, 399–418. New York: Academic Press.

Kitchener, Richard F. 2004. Russell’s Flirtation with Behaviorism. Behavior and Philosophy 32: 273–291.

Koch, Sigmund. 1964. Psychology and Emerging Conceptions of Knowledge as Unitary. In Behaviorism and Phenomenology, ed. T. W. Wann, 1–41. Chicago: University of Chicago Press.

La Mettrie, Julien Offray de. [1748] 1996. Man a Machine. Trans. Richard Watson. Indianapolis, IN: Hackett.

Lashley, Karl. 1923. A Behavioristic Interpretation of Consciousness. Psychological Review 23: 446–464.

MacKenzie, Brian D. 1977. Behaviorism and the Limits of Scientific Method. London: Routledge and Kegan Paul.

McDougall, William. 1912. Psychology: The Study of Behavior. New York: Holt.

Meyer, Max. 1921. The Psychology of the Other One. Columbus: Missouri Book Company.

O’Donnell, John M. 1985. The Origins of Behaviorism: American Psychology, 1870–1920. New York: New York University Press.

O’Donohue, William, and Richard Kitchener, eds. 1999. Handbook of Behaviorism. San Diego, CA: Academic Press.

Pavlov, Ivan. [1927] 1960. Conditioned Reflexes. Trans. Gleb V. Anrep. New York: Dover.

Peters, R. S. 1973–1974. Behaviorism. In Dictionary of the History of Ideas, ed. Philip Wiener, 214–229. New York: Scribner.

Putnam, Hilary. 1975. Brains and Behavior. In Philosophical Papers, vol. 2: Mind, Language, and Reality, 325–341. Cambridge, U.K.: Cambridge University Press.

Quine, W. V. O. 1960. Word and Object. Cambridge, MA: MIT Press.

Rachlin, Howard. 1991. Introduction to Modern Behaviorism. 3rd ed. New York: Freeman.

Rorty, Richard, ed. 1967. The Linguistic Turn. Chicago: University of Chicago Press.

Rosenfeld, Leonora C. 1941. From Beast-Machine to Man-Machine: Animal Soul in French Letters from Descartes to La Mettrie. New York: Oxford University Press.

Russell, Bertrand. 1921. An Analysis of Mind. London: Allen and Unwin.

Russell, Bertrand. 1927. An Outline of Psychology. New York: W. W. Norton.

Ryle, Gilbert. 1949. The Concept of Mind. New York: Barnes and Noble.

Schwartz, Barry, and Hugh Lacey. 1982. Behaviorism, Science, and Human Nature. New York: Norton.

Skinner, B. F. 1938. The Behavior of Organisms. New York: Appleton-Century-Crofts.

Skinner, B. F. 1957. Verbal Behavior. New York: Appleton-Century-Crofts.

Skinner, B. F. 1974. About Behaviorism. New York: Knopf.

Smith, L. 1986. Behaviorism and Logical Positivism: A Reassessment of Their Alliance. Stanford, CA: Stanford University Press.

Staddon, John. 2001. The New Behaviorism: Mind, Mechanism, and Society. Philadelphia: Psychology Press.

Tolman, Edwin C. 1932. Purposive Behavior in Animals and Men. New York: Appleton-Century-Crofts.

Turing, Alan. 1950. Computing Machinery and Intelligence. Mind 59: 433–490.

Watson, John. 1913. Psychology as the Behaviorist Views. Psychological Review 20: 158–177.

Watson, John. 1914. Behavior: An Introduction to Comparative Psychology. New York: Holt, Rinehart, and Winston.

Watson, John. 1919. Psychology from the Standpoint of a Behaviorist. Philadelphia: J. B. Lippincott.

Watson, John. 1925. Behaviorism. New York: W. W. Norton.

Weiss, Albert. 1925. A Theoretical Basis of Human Behavior. Columbus, OH: Adams.

Wittgenstein, Ludwig. 1953. Philosophical Investigations. Trans. G. E. M. Anscombe. Oxford, U.K.: Blackwell.

Zuriff, Gerald. 1985. Behaviorism: A Conceptual Reconstruction. New York: Columbia University Press.

Richard F. Kitchener

BEHAVIORISM.

Behaviorism is a theoretical approach in psychology that emphasizes the study of behavior—that is, the outwardly observable reactions to a stimulus of an organism, whether animal or human—rather than the content of the mind or the physiological correlates of behavior. Largely centered in the United States, behaviorism had an early stage (1910–1930) that was dominated by the work of the comparative psychologist John B. Watson, and a later stage, neo-behaviorism (1930–1955), defined by the psychologists Edward C. Tolman, Clark Hull, and B. F. Skinner.

Behaviorism has its roots in the work of Ivan Pavlov (1849–1936), a Russian physiologist who studied medicine in St. Petersburg and physiology at the University of Breslau in Germany. Pavlov designed a series of experiments to understand learning, a psychological process, in terms of the physiological process of conditioning, or training, reflex responses. His experimental animal of choice was the dog, though he expected that his results could apply to humans as well. Dogs normally display a salivation reflex at the sight of food. Pavlov's experiment involved ringing a bell at the same moment that the dog was presented with food. After presenting both stimuli in this joint manner, Pavlov simply rang the bell without also presenting the food—and found that the dog salivated. The normal reflex had been conditioned to appear in response to an unconventional stimulus. An organism's innate responses could thus be trained by this conditioning method to be elicited by a range of stimuli that did not normally produce them, and Pavlov used the method to examine the ways in which responses could be excited and inhibited. The method of conditioning reflexes could, according to Pavlov, replace a mentalistic language about what animals see or hear or feel with a physicalistic, materialist language about responses to stimuli. The conditioning method focused on outward, objective observation of animal behavior, rather than on guessing about the content of an animal's mind. In Pavlov's interpretation, seemingly purposeful behavior on the part of the animal could be reduced to the training of reflexes, or the formation and breaking of habits. Such a view bears a strong similarity to that of the behaviorists who followed, but in an important respect Pavlov differed from them. He never abandoned the idea that he was basically a physiologist and that there could be no science of psychology independent of physiology. Pavlov intended that the acts comprising an animal's behavior should eventually be explained in terms of the workings of its brain. He had no patience with the American behaviorists' belief that behavior formed its own autonomous branch of scientific study.

Behaviorism (1910–1930)

Pavlov's experiments in classical conditioning were familiar to Western psychologists from 1906 on and formed the heart of the behaviorist method. In 1913 John B. Watson (1878–1958) systematically and provocatively set out the principles of behaviorism in a manifesto entitled "Psychology As the Behaviorist Views It." Watson was a comparative psychologist interested in making psychology a real science by defining it as the study of outwardly observable behavior, rather than of thought, imagery, consciousness, or mind. In doing so he intended to break psychology's ties with philosophy. As a comparative psychologist with interests also in developmental psychology—the study of how the mind develops in childhood, as well as over the course of evolution—Watson knew that the conventional psychological method of introspection was inapplicable to the subjects of his science. Children and animals could not be asked to introspect, to divulge the contents of their minds, and guessing at what they were thinking Watson judged to be unscientific. Focusing instead on behavior rather than on consciousness was therefore the only way to proceed. Watson also had a practical motivation for his behaviorism—he wanted to make it the science of how people act.

Watson was born in Greenville, South Carolina. He attended college at Furman University and graduate school in the department of philosophy at the University of Chicago, where he was trained in comparative psychology by the neurologist Henry Herbert Donaldson and the psychologist James Rowland Angell. Watson was interested in the work of Jacques Loeb (1859–1924), a German-trained materialist physiologist at Chicago who studied tropisms, or movements in plants and animals, that he interpreted in solely physico-chemical terms. Donaldson and Angell, however, dissuaded Watson from working with the radical Loeb, and Watson instead wrote his dissertation on the correlation between brain growth and learning ability in rats.

In 1908 Watson became professor of psychology at the Johns Hopkins University, but as a comparative psychologist felt marginalized in the department. In his 1913 manifesto he devised a way to bring comparative psychology to center stage. A truly scientific psychology, he wrote, would abandon talk of mental states or conscious content of minds and instead focus on prediction and control of behavior. By focusing on objectively observable behavior, by getting away from mind, consciousness, and introspection and examining physical variables instead, psychology would become a legitimate science. Like Pavlov, Watson believed in observing and training physical responses to stimuli, making no reference to mind, and thereby treating animal and human behavior on the same level. In his 1919 book, Psychology From the Standpoint of a Behaviorist, Watson rejected the concept of mind completely, interpreting even imagery, thought, and language all in terms of behavior accessible to an objective observer.

At Johns Hopkins, Watson was associated with the psychiatrist Adolf Meyer, the head of the Phipps Clinic, where Watson applied behaviorist conditioning methods to children. In a famous series of experiments conducted with his graduate assistant Rosalie Rayner, Watson trained a child by the name of Little Albert (aged 9–13 months) to fear a rat, a response the child then produced in reaction to the sight of any furry creature. Watson's evident success in training even such a deep-seated reaction as fear led him to believe that all of a person's behavior could be altered, any habit could be formed or broken, by the engineering of stimuli—that is, by the control of the person's immediate environment. In his 1924 book Behaviorism Watson expressed this environmentalist view in its most extreme terms. But by then Watson had been forced to resign his position at Hopkins because of his involvement in an extramarital love affair with Rayner. He and Rayner moved to New York City, where Watson joined the John Walter Thompson advertising agency, and where both Watson and Rayner became popular authorities on child-rearing according to behaviorist principles. Their Psychological Care of Infant and Child appeared in 1928.

Watson was not the only psychologist during the 1910s to advocate behaviorism. At Columbia University Teachers College, Edward L. Thorndike (1874–1949), experimenting with cats learning their way around puzzle-boxes, similarly argued that the study of objectively observable changes in behavior, and their correlation with changes in stimuli, formed the heart of a legitimately scientific psychology. Thorndike formulated the law of effect, which held that pleasure or reward will reinforce a certain behavior, while pain will extinguish it: thus the animal's experience has important consequences for its behavior.

Neobehaviorism (1930–1955)

The second phase of behaviorism, neobehaviorism, was associated with Edward C. Tolman (1886–1959), Clark Hull (1884–1952), and B. F. Skinner (1904–1990). Like Thorndike, Watson, and Pavlov, the neobehaviorists believed that the study of learning and a focus on rigorously objective observational methods were the keys to a scientific psychology. Unlike their predecessors, however, the neobehaviorists were more self-consciously trying to formalize the laws of behavior. They were also influenced by the Vienna Circle of logical positivists, a group of philosophers led by Rudolph Carnap (1891–1970), Otto Neurath (1882–1945), and Herbert Feigl (1902–1988), who argued that meaningful statements about the world had to be cast as statements about physical observations. Anything else was metaphysics or nonsense, not science, and had to be rejected. Knowledge, according to the logical positivists, had to be built on an observational base, and could be verified to the extent that it was in keeping with observation.

A professor of psychology at the University of California at Berkeley, Tolman focused his experimental work largely on white rats learning their way through mazes. He differed from his behaviorist predecessors by taking a more holistic approach to behavior than they had. Rather than talking in terms of atomistic, isolated stimuli and responses, Tolman emphasized their integration with the environment by referring to them as "stimulating agencies" and "behavior acts." In his 1932 Purposive Behavior in Animals and Men, Tolman argued that purpose and cognition were essential to behavior and should be interpreted not as mentalistic entities but as outwardly observable features of behavior describable in objective language. He also defined the notion of the intervening variable, a link between stimulus and response that helps to determine behavior. As many as ten intervening variables could exist between a stimulating agency and a rat's decision to move in a certain direction at a choice-point in a maze.

Of the three neobehaviorists, Hull was the most ambitious about constructing a formal theory of behavior. He believed he had found the fundamental law of learning or habit-formation—the law of stimulus generalization—and that this law not only underlay all behavior in animals and humans, but was a principle basic enough to unify all the social sciences. According to the law, a response could be called forth by an unconventional stimulus as long as that stimulus was associated, either temporally or in character, with the stimulus that usually called forth the response. As long as the unconventional stimulus was similar enough to the usual one, it could elicit the response. Pavlov had noted this effect when his dogs salivated at the ringing of a bell. Hull further theorized that learning was continuous—that is, when an animal was trained to respond to a particular positive stimulus (or avoid a negative stimulus), all aspects of that stimulus impinging on the animal's sensorium were gradually associated with that response. Thus the animal learns in an incremental way, not in an all-or-nothing burst, and thus engineering the appearance of stimuli could precisely control the animal's ability to form habits. These laws of behavior explained how all learning took place without resorting to immaterial notions like soul or free will. Hull, who had originally intended to become an engineer, even designed a variety of machines that worked on the principles of conditioning reflexes, in order to demonstrate that learning was a wholly mechanistic process. He expressed his laws of behavior in mathematical terms, filling his 1943 Principles of Behavior: An Introduction to Behavior Theory with complex equations.

The rigor for which Hull strove in his science was evident both in his exclusion of any nonmaterial entity and in his formulation of laws. It was also evident in the hypothetico-deductive method by which he believed psychologists must work. Here Hull's inspiration was the certainty of scientific knowledge achieved by the natural philosopher Isaac Newton (1642–1727). In Hull's method, the theorist began with the observation of a certain behavior, derived axioms from that observation, deduced consequences from the axioms, tested the consequences through experiment, and then refined the axioms, ultimately establishing the laws of behavior on a firm observational and experimental footing. In 1929 Hull moved from his teaching position at the University of Wisconsin at Madison to a prestigious post at the Rockefeller Foundation–funded Institute of Human Relations at Yale, where he remained until his death in 1952. Hull's laws of behavior and his rigorous scientific method became central to the Institute's mission to unify the social sciences. Hull's theory of behavior integrated psychology, psychiatry, sociology, and anthropology by describing learning as the forging of connections between stimulus and response, and then envisioning this mechanism as the mediator of all social and cultural activity. The build-up and breakdown of habit was thus interpreted as the key to all behavior. Hull and his work formed the focal points of the Institute of Human Relations, which lasted only as long as Hull lived and was dissolved after his death. His approach was, however, continued by his friend and supporter Kenneth Spence (1907–1967), a psychologist at the University of Iowa.

The Harvard psychologist B. F. Skinner, the third of the important neobehaviorists, rejected Hull's attempts at formal theory building and returned to the Watsonian project of founding a science entirely on the observation of behavior. Skinner devised an experimental set-up, the so-called Skinner box, in which a pigeon or a rat would be rewarded for accomplishing an act, such as raising its head above a certain line, or pressing a lever, by the release of food pellets. In his 1938 Behavior of Organisms, Skinner explained that a movement rewarded in this way was reinforced—that is, made more likely to occur—while one that was punished was stamped out. A behavior that was followed by the repetition of that behavior—a movement selected and maintained by its positive consequences—Skinner called the operant. His approach therefore was referred to as operant conditioning. Both animals and people behave the way they do because of the positive consequences produced by past behavior. For Skinner, all learning was a matter of such reinforcement, and his method consisted of recording sequences of movements that revealed the patterns by which behavior was reinforced. He avoided talking about habit formation, and even about stimuli, restricting his science to the observation of these movement patterns.

In his 1953 Science and Human Behavior, Skinner explained the principles that underlay his psychology. First, he argued that his science was entirely based in observation, and that theories and hypotheses played a limited role in it: his approach was radically inductivist and empiricist. Second, since psychology was supposed to be restricted to the level of behavioral observation, it had no need of being reduced to or explained in terms of physiology. Physiology was not more fundamental than psychology—it was either unobservable, hence unscientific, or part of behavior itself. Third, for Skinner, mental processes or states were to be interpreted as behavior—memory, knowledge, imagery, and other such mentalistic entities he dismissed as metaphors or fictions. Past consequences of behavior, not mental states, motivated future action. Skinner's 1957 Verbal Behavior was his attempt to deal with thought and language in terms of reinforced movements. Finally, Skinner believed that biological adaptation was the ultimate criterion for the persistence of a behavior: if an action aided survival, it persisted.

Skinner argued that behavior could be shaped, or controlled, by controlling the rewards or reinforcements meted out in response to them—that is, by controlling the environment. In the mid 1950s and 1960s, some penal and psychiatric institutions adopted this method of behavior modification to shape the behavior of their inmates. In his 1948 book Walden Two, Skinner had prepared the ground for such application of his science by imagining a utopian community led according to behaviorist principles. In his 1971 Beyond Freedom and Dignity, Skinner argued that such ethical principles as free will and individual responsibility are simply illusions, and what will make us truly free is the realization that behavior is instead controlled by the past and by the environment.

Neobehaviorism came in for strong criticism in the late 1950s and 1960s. Philosophers of science questioned the claim that any science could be theory-neutral and based solely in observation; observations were themselves seen to be theory-laden. Psychologists questioned the idea that learning was a singular entity that could form the basis for all of psychology. In particular, cognitive psychology, drawing on insights from computer science, redefined mental processes such as problem solving, learning, and memory in terms of information processing, a development that gave a new autonomy and a new respectability to the study of internal mental states. Influenced by this cognitivist turn, the psycholinguist Noam Chomsky (b. 1928) published a scathing review of Skinner's Verbal Behavior, arguing that language had to be understood in terms of universal and innate mental structures, not as behavior shaped by the environment. Behaviorism is currently regarded by psychologists as one approach among many; both cognitivism and neuroscience are arguably as influential in understanding mind and behavior.

See also Biology ; Determinism ; Education: North America ; Psychology and Psychiatry .

bibliography

Amsel, Abram. Behaviorism, Neobehaviorism, and Cognitivism in Learning Theory: Historical and Contemporary Perspectives. Hillsdale, N.J.: Erlbaum, 1989.

Boakes, Robert. From Darwin to Behaviorism: Psychology and the Minds of Animals. New York: Cambridge University Press, 1984.

Buckley, Kerry. Mechanical Man: John Broadus Watson and the Beginnings of Behaviorism. New York: Guilford Press, 1989.

Harris, Benjamin. "Whatever Happened to Little Albert?" American Psychologist 34 (1979): 151–160.

Hull, Clark L. Principles of Behavior: An Introduction to Behavior Theory. New York: Appleton Century Crofts, 1943.

Mills, John A. Control: A History of Behavioral Psychology. New York: New York University Press, 1998.

Morawski, J. G. "Organizing Knowledge and Behavior at Yale's Institute of Human Relations." Isis 77 (1986): 219–242.

O'Donnell, John M. The Origins of Behaviorism: American Psychology, 1870–1920. New York: New York University Press, 1985.

Pavlov, Ivan P. Conditioned Reflexes. Translated by G. Anrep. Oxford: Oxford University Press, 1927.

Samelson, Franz. "Struggle for Scientific Authority: The Reception of Watson's Behaviorism, 1913–1920." JHBS 17 (1981): 399–425.

Skinner, B. F. The Behavior of Organisms. New York: Appleton Century Crofts, 1938.

Smith, Laurence D. Behaviorism and Logical Positivism: A Reassessment of the Alliance. Stanford, Calif.: Stanford University Press, 1986.

Tolman, Edward C. "A New Formula for Behaviorism." Psychological Review 29 (1922): 44–53.

Watson, John B. "Psychology as the Behaviorist Views It." Psychological Review 20 (1913): 158–178.

Weidman, Nadine M. Constructing Scientific Psychology: Karl Lashley's Mind-Brain Debates. New York: Cambridge University Press, 1999.

Nadine Weidman

BEHAVIORISM

Behaviorism is the conceptual framework underlying the science of behavior. The science itself is often referred to as the experimental analysis of behavior or behavior analysis. Modern behaviorism emphasizes the analysis of conditions that maintain and change behavior as well as the factors that influence the acquisition or learning of behavior. Behaviorists also offer concepts and analyses that go well beyond the common-sense understanding of reward and punishment. Contemporary behaviorism provides an integrated framework for the study of human behavior, society, and culture.

Within the social sciences, behaviorism has referred to the social-learning perspective that emphasizes the importance of reinforcement principles in regulating social behavior (McLaughlin 1971). In addition, sociologists such as George Homans and Richard Emerson have incorporated the principles of behavior into their theories of elementary social interaction or exchange (Emerson 1972; Homans 1961). The basic idea in social exchange approaches is that humans exchange valued activities (e.g., giving respect and getting help) and that these transactions are "held together" by the principle of reinforcement. That is, exchange transactions that involve reciprocal reinforcement by the partners increase in frequency or probability; those transactions that are not mutually reinforcing or are costly to the partners decrease in frequency over time. There is a growing body of research literature supporting social exchange theory as a way of understanding a variety of social relationships.

SOME BASIC ISSUES

The roots of behaviorism lie in its philosophical debate with introspectionism—the belief that the mind can be revealed from a person's reports of thoughts, feelings, and perceptions. Behaviorists opposed the use of introspective reports as the basic data of psychology. These researchers argued for a natural-science approach and showed how introspective reports of consciousness were inadequate. Reports of internal states and experiences were said to lack objectivity, were available to only one observer, and were prone to error. Some behaviorists used these arguments and also others to reject cognitive explanations of behavior (Skinner 1974; Pierce and Epling 1984; but see Bandura 1986 for an alternative view).

The natural-science approach of behaviorism emphasizes the search for general laws and principles of behavior. For example, the quantitative law of effect is a mathematical statement of how the rate of response increases with the rate of reinforcement (Herrnstein 1970). Under controlled conditions, this equation allows the scientist to predict precisely and to regulate the behavior of organisms. Behavior analysts suggest that this law and other behavior principles will eventually account for complex human behavior (McDowell 1988).

Contemporary behaviorists usually restrict themselves to the study of observable responses and events. Observable events are those that are directly sensed or are made available to our senses by instruments. The general strategy is to manipulate aspects of the environment and measure well-defined responses. If behavior reliably changes with a manipulated condition, the researcher has established an environment-behavior relationship. Analysis of such relationships has often resulted in behavioral laws and principles. For example, the principle of discrimination states that an organism will respond differently to two situations if its behavior is reinforced in one setting but not in the other. You may talk about politics to one person but not to another, because the first person has been interested in such conversation in the past while the second has not. The principle of discrimination and other behavior principles account for many aspects of human behavior.

Although behaviorism usually has been treated as a uniform and consistent philosophy and science, a conceptual reconstruction indicates that there are many branches to the behavioral tree (Zuriff 1985). Most behavior analysts share a set of core assumptions; however, there are internal disputes over less central issues. To illustrate, some behaviorists argue against hypothetical constructs (e.g., memory) while others accept such concepts as an important part of theory construction.

Throughout the intellectual history of behaviorism, a variety of assumptions and concepts has been presented to the scientific community. Some of these ideas have flourished when they were found to further the scientific analysis of behavior. Other formulations were interesting variations of behavioristic ideas, but they became extinct when they served no useful function. For instance, one productive assumption is that a person's knowledge of emotional states is due to a special history of verbal conditioning (Bem 1965, 1972; Skinner 1957). Self-perception and attributional approaches to social psychology have built on this assumption, although researchers in this field seldom acknowledge the impact. In contrast, the assumption that thinking is merely subvocal speech was popular at one time but is now replaced by an analysis of problem solving (Skinner 1953, 1969). In this view, thinking is behavior that precedes and guides the final performance of finding a solution. Generally, it is important to recognize that behaviorism continues to evolve as a philosophy of science, a view of human nature, and an ideology that recommends goals for behavioral science and its applications.

THE STUDY OF BEHAVIOR

Behaviorism requires that a scientist study the behavior of organisms for its own sake. Behaviorists do not study behavior in order to make inferences about mental states or physiological processes. Although most behaviorists emphasize the importance of biology and physiological processes, they focus on the interplay of behavior and environment.

In order to maintain this focus, behaviorists examine the evolutionary history and physiological status of an organism as part of the context for specific environment-behavior interactions. For example, a biological condition that results in blindness may have profound behavioral effects. For a newly sightless individual, visual events, such as watching television or going to a movie no longer support specific interactions, while other sensory events become salient (e.g., reading by braille). The biological condition limits certain kinds of behavioral interactions and, at the same time, augments the regulation of behavior by other aspects of the environment. Contemporary behaviorism therefore emphasizes what organisms are doing, the environmental conditions that regulate their actions, and how biology and evolution constrain or enhance environment-behavior interactions.

Modern behaviorists are interested in voluntary action, and they have developed a way of talking about purpose, volition, and intention within a natural-science approach. They note that the language of intention was pervasive in biology before Darwin's functional analysis of evolution. Although it appears that giraffes grow long necks in order to obtain food at the tops of trees, Darwin made it clear that the process of evolution involved no plan, strategy of design, or purpose. Natural variation ensures that giraffes vary in neck size. As vegetation declines at lower heights, animals with longer necks obtain food, survive to adulthood, and reproduce; those with shorter necks starve to death. In this environment (niche), the frequency of long-necked giraffes increases over generations. Such an increase is called natural selection. Contemporary behaviorists insist that selection, as a causal mode, also accounts for the form and frequency of behavior during the lifetime of an individual. A person's current behavior is therefore composed of performances that have been selected in the past (Skinner 1987).

An important class of behavior is selected by its consequences. The term operant refers to behavior that operates upon the environment to produce effects, outcomes, or consequences. Operant behavior is said to be emitted because it does not depend on an eliciting stimulus. Examples of operant behavior include manipulation of objects, talking with others, problem solving, drawing, reading, writing, and many other performances. Consequences select this behavior in the sense that specific operants occur at high frequency in a given setting. To illustrate, driving to the store is operant behavior that is likely to occur when there is little food in the house. In this situation, the operant has a high probability if such behavior has previously resulted in obtaining food (i.e. the store is open). Similarly, the conversation of a person also is selected by its social consequences. At the pub, a student shows high probability of talking to his friends about sports. Presumably, this behavior occurs at high frequency because his friends have previously "shown an interest" in such conversation. The behavior of an individual is therefore adapted to a particular setting by its history of consequences.

A specific operant, such as opening a door, includes many performance variations. The door may be opened by turning the handle, pushing with a foot, or even by asking someone to open it. These variations in performance have a common effect upon the environment in the sense that each one results in the door being opened. Because each variation produces similar consequences, behaviorists talk about an operant as a response class. Operants such as opening a door, talking to others, answering questions, and many other actions are each a response class that includes a multitude of forms, both verbal and nonverbal.

In the laboratory, the study of operant behavior requires a basic measure that is sensitive to changes in the environment. Most behaviorists use an operant's rate of occurrence as the basic data for analysis. Operant rate is measured as the frequency of an operant (class) over a specified period of time. Although operant rate is not directly observable, a cumulative recorder is an instrument that shows the rate of occurrence as changes in the slope (or rise) of a line on moving paper. When an operant is selected by its consequences, the operant rate increases and the slope becomes steeper. Operants that are not appropriate to the requirements of the environment decrease in rate of occurrence (i.e., decline in slope). Changes in operant rate therefore reflect the basic causal process of selection by consequences (Skinner 1969).

Behavior analysts continue to use the cumulative recorder to provide an immediate report on a subject's behavior in an experimental situation. However, most researchers are interested in complex settings where there are many alternatives and multiple operants. Today, microcomputers collect and record a variety of behavioral measures that are later examined by complex numerical analysis. Researchers also use computers to arrange environmental events for individual behavior and provide these events in complex patterns and sequences.

CONTINGENCIES OF REINFORCEMENT

Behaviorists often focus on the analysis of environment-behavior relationships. The relationship between operant behavior and its consequences defines a contingency of reinforcement. In its simplest form, a two-term contingency of reinforcement may be shown as R(Sr. The symbol R represents the operant class, and Sr stands for the reinforcing stimulus or event. The arrow indicates that "if R occurs, then Sr will follow." In the laboratory, the behavior analyst arranges the environment so that a contingency exists between an operant (e.g., pecking a key) and the occurrence of some event (e.g., presentation of food). If the presentation of the event increases operant behavior, the event is defined as a positive reinforcer. The procedure of repeatedly presenting a positive reinforcer contingent on behavior is called positive reinforcement (see Pierce and Epling 1999).

A contingency of reinforcement defines the probability that a reinforcing event will follow operant behavior. When a person turns the ignition key of the car (operant), this behavior usually has resulted in the car starting (reinforcement). Turning the key does not guarantee, however, that the car will start; perhaps it is out of gas, the battery is run down, and so on. Thus, the probability of reinforcement is high for this behavior, but reinforcement is not certain. The behavior analyst is interested in how the probability of reinforcement is related to the rate and form of operant behavior. For example, does the person continue to turn the ignition key even though the car doesn't start? Qualities of behavior such as persistence, depression, and elation reflect the probability of reinforcement.

Reinforcement may depend on the number of responses or the passage of time. A schedule of reinforcement is a procedure that states how consequences are arranged for behavior. When reinforcement is delivered after each response, a continuous schedule of reinforcement is in effect. A child who receives payment each time she mows the lawn is on a continuous schedule of reinforcement. Continuous reinforcement produces a very high and steady rate of response, but as any parent knows, the behavior quickly stops if reinforcement no longer occurs.

Continuous reinforcement is a particular form of ratio schedule. Fixed-ratio schedules state the number of responses per reinforcement. These schedules are called fixed ratio since a fixed number of responses are required for reinforcement. In a factory, piece rates of payment are examples of fixed-ratio schedules. Thus, a worker may receive $1 for sewing twenty pieces of elastic wristband. When the ratio of responses to reinforcement is high (value per unit output is low), fixed-ratio schedules produce long pauses following reinforcement: Overall productivity may be low, leading plant managers to complain about "slacking off" by the workers. The problem, however, is the schedule of reinforcement that fixes a high number of responses to payment.

Reinforcement may be arranged on a variable, rather than fixed, basis. The schedule of payoff for a slot machine is a variable-ratio schedule of reinforcement. The operant involves putting in a dollar and pulling the handle, and reinforcement is the jackpot. The jackpot occurs after a variable number of responses. Variable-ratio schedules produce a high rate of response that takes a long time to stop when reinforcement is withdrawn. The gambler may continue to put money in the machine even though the jackpot rarely, if ever, occurs. Behavior on a variable-ratio schedule is said to show negative utility since people often invest more than they get back.

Behavior may also be reinforced only after an interval of time has passed. A fixed-interval schedule stipulates that the first response following a specified interval is reinforced. Looking for a bus is behavior that is reinforced after a fixed time set by the bus schedule. If you just missed a bus, the probability of looking for the next one is quite low. As time passes, the rate of response increases with the highest rate occurring just before the bus arrives. Thus, the rate of response is initially zero but gradually rises to a peak at the moment of reinforcement. This response pattern is called scalloping and is characteristic of fixed-interval reinforcement. In order to eliminate such patterning, a variable-interval schedule may be stipulated. In this case, the first response after a variable amount of time is reinforced. If a person knows by experience that bus arrivals are irregular, looking for the next bus will occur at a moderate and steady rate because the passage of time no longer signals reinforcement (i.e., arrival of the bus).

The schedules of reinforcement that regulate human behavior are complex combinations of ratio and interval contingencies. An adjusting schedule is one example of a more complex arrangement between behavior and its consequences (Zeiler 1977). When the ratio (or interval) for reinforcement changes on the basis of performance, the schedule is called adjusting. A math teacher who spends more or less time with a student depending on the student's competence (i.e., number of correct solutions) provides reinforcement on an adjusting-ratio basis. When reinforcement is arranged by other people (i.e., social reinforcement), the level of reinforcement is often tied to the level of behavior (i.e., the greater the strength of response the less the reward from others). This adjustment between behavior and socially arranged consequences may account for the flexibility and variability that characterize adult human behavior.

Human behavior is regulated not only by its consequences. Contingencies of reinforcement also involve the events that precede operant behavior. The preceding event is said to "set the occasion" for behavior and is called a discriminative stimulus or Sd. The ring of a telephone (Sd) may set the occasion for answering it (operant), although the ring does not force one to do so. Similarly, a nudge under the table (Sd) may prompt a new topic of conversation (operant) or cause the person to stop speaking. Discriminative stimuli may be private as well as public events. Thus, a headache may result in taking a pill or calling a physician. A mild headache may be discriminative stimulus for taking an aspirin, while more severe pain sets the occasion for telephoning a doctor.

Although discriminative stimuli exert a broad range of influences over human behavior, these events do not stand alone. These stimuli regulate behavior because they are an important part of the contingencies of reinforcement. Behaviorism has therefore emphasized a three-term contingency of reinforcement, symbolized as Sd:R(r)Sr. The notation states that a specific event (Sd) sets the occasion for an operant (R) that produces reinforcement (Sr). The discriminative stimulus regulates behavior only because it signals past consequences. Thus, a sign that states "Eat at Joe's" may set the occasion for your stopping at Joe's restaurant because of the great meals received in the past. If Joe hires a new cook, and the meals deteriorate in quality, then Joe's sign will gradually lose its influence. Similarly, posted highway speeds regulate driving on the basis of past consequences. The driver who has been caught by a radar trap is more likely to observe the speed limit.

CONTEXT OF BEHAVIOR

Contingencies of reinforcement, as complex arrangements of discriminative stimuli, operants, and reinforcements, remain a central focus of behavioral research. Contemporary behaviorists are also concerned with the context of behavior, and how context affects the regulation of behavior by its consequences (Fantino and Logan 1979). Important aspects of context include the biological and cultural history of an organism, its current physiological status, previous environment—behavior interactions, alternative sources of reinforcement, and a history of deprivation (or satiation) for specific events or stimuli. To illustrate, in the laboratory food is used typically as an effective reinforcer for operant behavior. There are obvious times, however, when food will not function as reinforcement. If a person (or animal) has just eaten a large meal or has an upset stomach, food has little effect upon behavior.

There are less obvious interrelations between reinforcement and context. Recent research indicates that depriving an organism of one reinforcer may increase the effectiveness of a different behavioral consequence. As deprivation for food increased, animals worked harder to obtain an opportunity to run on a wheel. Additionally, animals who were satiated on wheel running no longer pressed a lever to obtain food. These results imply that eating and running are biologically interrelated. Based on this biological history, the supply or availability of one of these reinforcers alters the effectiveness of the other (Pierce, Epling, and Boer 1986). It is possible that many reinforcers are biologically interrelated. People commonly believe that sex and aggression go together in some unspecified manner. One possibility is that the availability of sexual reinforcement alters the reinforcing effectiveness of an opportunity to inflict harm on others.

CHOICE AND PREFERENCE

The emphasis on context and reinforcement contingencies has allowed modern behaviorists to explore many aspects of behavior that seem to defy a scientific analysis. Most people believe that choice and preference are basic features of human nature. Our customary way of speaking implies that people make decisions on the basis of their knowledge and dispositions. In contrast, behavioral studies of decision making suggest that we choose an option based on its rate of return compared with alternative sources of reinforcement.

Behaviorists have spent the last thirty years studying choice in the laboratory using concurrent schedules of reinforcement. The word concurrent means "operating at the same time." Thus, concurrent schedules are two (or more) schedules operating at the same time, each schedule providing reinforcement independently. The experimental setting is arranged so that an organism is free to alternate between two or more alternatives. Each alternative provides a schedule of reinforcement for choosing it over the other possibilities. A person may choose between two (or more) response buttons that have different rates of monetary payoff. Although the experimental setting is abstract, concurrent schedules of reinforcement provide an analogue of choice in everyday life.

People are often faced with a variety of alternatives, and each alternative has its associated benefits (and costs). When a person puts money in the bank rather than spending it on a new car, television, or refrigerator, we speak of the individual choosing to save rather than spend. In everyday life, choice often involves repeated selection of one alternative (e.g. putting money in the bank) over the other alternatives considered as a single option (e.g. buying goods and services). Similarly, the criminal chooses to take the property of others rather than take the socially acceptable route of working for a living or accepting social assistance. The arrangement of consequences for crime and legitimate ways of making a living is conceptually the same as concurrent schedules of reinforcement (Hamblin and Crosbie 1977).

Behaviorists are interested in the distribution or allocation of behavior when a person is faced with different rates of reinforcement from two (or more) alternatives. The distribution of behavior is measured as the relative rate of response to, or relative time spent on, a specific option. For example, a student may go to school twelve days and skip eight days each month (not counting weekends). The relative rate of response to school is the proportion of the number of days at school to the total number of days, or 12/20 = 0.60. Expressed as a percentage, the student allocates 60 percent of her behavior to school. In the laboratory, a person may press the left button twelve times and the right button eight times each minute.

The distribution of reinforcement may also be expressed as a percentage. In everyday life, it is difficult to identify and quantify behavioral consequences, but it is easily accomplished in the laboratory. If the reinforcement schedule on the left button produces $30 an hour and the right button yields $20, 60 percent of the reinforcements are on the left. There is a fundamental relationship between relative rate of reinforcement and relative rate of response. This relationship is called the matching law. The law states that the distribution of behavior to two (or more) alternatives matches (equals) the distribution of reinforcement from these alternatives (Herrnstein 1961; de Villiers 1977).

Although it is difficult to identify rates of reinforcement for attending school and skipping, the matching law does suggest some practical solutions (Epling and Pierce 1988). For instance, parents and the school may be able to arrange positive consequences when a child goes to school. This means that the rate of reinforcement for going to school has increased, and therefore the relative rate of reinforcement for school has gone up. According to the matching law, a child will now distribute more behavior to the school.

Unfortunately, there is another possibility. A child may receive social reinforcement from friends for skipping, and as the child begins to spend more time at school, friends may increase their rate of reinforcement for cutting classes. Even though the absolute rate of reinforcement for going to school has increased, the relative rate of reinforcement has remained the same or decreased. The overall effect may be no change in school attendance or even further decline. In order to deal with the problem, the matching law implies that interventions must increase reinforcement for attendance and maintain or reduce reinforcement for skipping, possibly by turning up the cost of this behavior (e.g., withdrawal of privileges).

The matching law has been tested with human and nonhuman subjects under controlled conditions. One interesting study assessed human performance in group discussion sessions. Subjects were assigned to groups discussing attitudes toward drug abuse. Each group was composed of three confederates and a subject. Two confederates acted as listeners and reinforced the subject's talk with brief positive words and phrases, provided on the basis of cue lights. Thus, the rate of reinforcement by each listener could be varied depending on the number of signals arranged by the researchers. A third confederate asked questions but did not reinforce talking. Results were analyzed in terms of the relative time subjects spent talking to the two listeners. Speakers matched their distribution of conversation to the distribution of positive comments from the listeners. Apparently, choosing to speak to others is behavior that is regulated by the matching law (Conger and Kileen 1974).

Researchers have found that exact matching does not always hold between relative rate of reinforcement and relative rate of response. A more general theory of behavioral matching has been tested in order to account for the departures from perfect matching. One source of deviation is called response bias. Bias is a systematic preference for an alternative, but the preference is not due to the difference in rate of reinforcement. For example, even though two friends provide similar rates of reinforcement, social characteristics (e.g., status and equity) may affect the distribution of behavior (Sunahara and Pierce 1982). Generalized matching theory is able to address many social factors as sources of bias that affect human choice and preference (Baum 1974; Pierce and Epling 1983; Bradshaw and Szabadi 1988).

A second source of deviation from matching is called sensitivity to differences in reinforcement. Matching implies that an increase of 10 percent (e.g., from 50 to 60 percent) in relative rate of reinforcement for one alternative results in a similar increase in relative rate of response. In many cases, the increase in relative rate of response is less than expected (e.g., only 5 percent). This failure to discriminate changes in relative rate of reinforcement is incorporated within the theory of generalized matching. To illustrate, low sensitivity to changes in rate of reinforcement may occur when an air-traffic controller rapidly switches between two (or more) radar screens. As relative rate of targets increases on one screen, relative rate of detection may be slow to change. Generalized matching theory allows behaviorists to measure the degree of sensitivity and suggests procedures to modify it (e.g., setting a minimal amount of time on a screen before targets can be detected).

Matching theory is an important contribution of modern behaviorism. In contrast to theories of rational choice proposed by economists and other social scientists, matching theory implies that humans may not try to maximize utility (or reinforcement). People (and animals) do not search for the strategy that yields the greatest overall returns; they equalize their behavior to the obtained rates of reinforcement from alternatives. Research suggests that matching (rather than maximizing) occurs because humans focus on the immediate effectiveness of their behavior. A person may receive a per-hour average of $10 and $5 respectively from the left and right handles of a slot machine. Although the left side generally pays twice as much, there are local periods when the left option actually pays less than the right. People respond to these changes in local rate of reinforcement by switching to the lean alternative (i.e., the right handle), even though they lose money overall. The general implication is that human impulsiveness ensures that choice is not a rational process of getting the most in the long run but a behavioral process of doing the best at the moment (Herrnstein 1990).

MATHEMATICS AND BEHAVIOR MODIFICATION

The matching law suggests that operant behavior is determined by the rate of reinforcement for one alternative relative to all other sources of reinforcement. Even in situations that involve a single response on a schedule of reinforcement, the behavior of organisms is regulated by alternative sources of reinforcement. A rat that is pressing a lever for food may gain additional reinforcement from exploring the operant chamber, scratching itself, and so on. In a similar fashion, rather than work for teacher attention a pupil may look out the window, talk to a friend, or even daydream. Thus in a single-operant setting, multiple sources of reinforcement are functioning. Herrnstein (1970) argued this point and suggested an equation for the single operant that is now called the quantitative law of effect.

Carr and McDowell (1980) applied Herrnstein's equation to a clinically relevant problem. The case involved the treatment of a 10-year-old boy who repeatedly and severely scratched himself. Before treatment the boy had a large number of open sores on his scalp, face, back, arms, and legs. In addition, the boy's body was covered with scabs, scars, and skin discoloration. In their review of this case, Carr and McDowell demonstrated that the boy's scratching was operant behavior. Careful observation showed that the scratching occurred more often when he and other family members were in the living room watching television. This suggested that a specific situation set the occasion for the self-injurious behavior. Further observation showed that family members repeatedly and reliably reprimanded the boy when he engaged in self-injury. Reprimands are seemingly negative events, but adult attention (whether negative or positive) can serve as reinforcement for children's behavior.

In fact, McDowell (1981) showed that the boy's scratching was in accord with Herrnstein's equation (i.e., the quantitative law of effect). He plotted the reprimands per hour on the x-axis and scatches per hour on the y-axis. When applied to this data, the equation provided an excellent description of the boy's behavior. The quantitative law of effect also suggested how to modify the problem behavior. In order to reduce scratching (or any other problem behavior), one strategy is to increase reinforcement for alternative behavior. As reinforcement is added for alternative behavior, problem behavior must decrease; this is because the reinforcement for problem behavior is decreasing (relative to total reinforcement) as reinforcement is added to other (acceptable) behavior.

APPLIED BEHAVIOR ANALYSIS AND
EDUCATION

The application of behavior principles to improve performance and solve social problems is called applied behavior analysis (Baer, Wolf, and Risley 1968). Principles of behavior change have been used to improve the performance of university students, increase academic skills in public and high school students, teach self-care to developmentally delayed children, reduce phobic reactions, get people to wear seat belts, prevent industrial accidents, and help individuals stop cocaine abuse, among other things. Behavioral interventions have had an impact on such things as clinical psychology, medicine, education, business, counseling, job effectiveness, sports training, the care and treatment of animals, environmental protection, and so on. Applied behavioral experiments have ranged from investigating the behavior of psychotic individuals to designing contingencies of entire institutions (see Catania and Brigham 1978; Kazdin 1994).

One example of applied behavior analysis in higher education is the method of personalized instruction. Personalized instruction is a self-paced learning system that contrasts with traditional lecture methods that often are used to instruct college students. In a university lecture, a professor stands in front of a number of students and talks about his or her area of expertise. There are variations on this theme (e.g., students are encouraged to be active rather than passive learners), basically the lecture method of teaching is the same as it has been for thousands of years.

Dr. Fred Keller (1968) recognized that the lecture method of teaching was inefficient and in many cases a failure. He reasoned that anyone who had acquired the skills needed to attend college was capable of successfully mastering most or all college courses. Some students might take longer than others to reach expertise in a course, but the overwhelming majority of students would be able to do so. If behavior principles were to be taken seriously, there were no bad students, only ineffective teaching methods.

In a seminal article, titled "Good-bye, teacher. . . ," Keller outlined a college teaching method based on principles of operant conditioning (Keller 1968). Keller's personalized system of instruction (PSI) involves arranging the course material in a sequence of graduated steps (units or modules). Each student moves through the course material at his or her own pace and the modules are set up to ensure that most students have a high rate of success learning the course content. Some students may finish the course in a few weeks, others require a semester or longer.

Course material is broken down into many small units of reading and (if required) laboratory assignments. Students earn points (conditioned reinforcement) for completing unit tests and lab assignments. Mastery of lab assignments and unit tests is required. If test scores are not close to perfect, the test (in different format) must be taken again after a review of the material for that unit. The assignments and tests build on one another so they must be completed in a specified order.

Comparison studies have evaluated student performance on PSI courses against the performance of students given computer-based instruction, audio-tutorial methods, traditional lectures, visual-based instruction, and other programmed instruction methods. College students instructed by PSI outperform students taught by these other methods when given a common final examination (see Lloyd and Lloyd 1992 for a review). Despite this positive outcome, logistical problems in organizing PSI courses such as teaching to mastery level (most students get an A for the course), and allowing students more time than the allotted semester to complete the course, have worked against widespread adoption of PSI in universities and colleges.

SUMMARY

Modern behaviorism emphasizes the context of behavior and reinforcement. The biological history of an organism favors or constrains specific environment-behavior interactions. This interplay of biology and behavior is a central focus of behavioral research. Another aspect of context concerns alternative sources of reinforcement. An individual selects a specific option based on the relative rate of reinforcement. This means that behavior is regulated not only by its consequences but also by the consequences arranged for alternative actions. As we have seen, the matching law and the quantitative law of effect are major areas of basic research that suggest new intervention strategies for behavior modification. Finally, applied behavior analysis, as a technology of behavior change, is having a wide impact on socially important problems of human behavior. A personalized system of instruction is an example of applied behavior analysis in higher education. Research shows that mastery-based learning is more effective than alternative methods of instruction, but colleges and universities its implementation.

references

Baer, D.M., M.M. Wolf, and T. R. Risley 1968 "Some

Current Dimensions of Applied Behavioral Analysis." Journal of Applied Behavior Analysis 1:91–97.

Bandura, A. 1986 Social Foundations of Thought and Action. Englewood Cliffs, N.J.: Prentice Hall.

Baum, W. M. 1974 "On Two Types of Deviation from the Matching Law: Bias and Undermatching." Journal of the Experimental Analysis of Behavior 22:231–242.

Bem, D. J. 1965 "An Experimental Analysis of Self-Persuasion." Journal of Experimental Social Psychology 1:199–218.

——1972 "Self-Perception Theory." In L. Berkowitz, ed., Advances in Experimental Social Psychology, Vol. 6. New York: Academic Press.

Bradshaw, C. M., and E. Szabadi 1988 "Quantitative Analysis of Human Operant Behavior." In G. Davey and C. Cullen, eds. Human Operant Conditioning and Behavior Modification. New York: Wiley.

Carr, E. G., and J. J. McDowell 1980 "Social Control of Self-Injurious Behavior of Organic Etiology." Behavior Therapy 11:402–409.

Catania, C. A., and T. A. Brigham, eds. 1978 Handbook of Applied Behavior Analysis: Social and Instructional Processes. New York: Irvington Publishers.

Conger, R., and P. Killeen 1974 "Use of Concurrent Operants in Small Group Research." Pacific Sociological Review 17:399–416.

De Villiers, P. A. 1977 "Choice in Concurrent Schedules and a Quantitative Formulation of the Law of Effect." In W. K. Honig and J. E. R. Staddon, eds., Handbook of Operant Behavior. Englewood Cliffs, N.J.: Prentice-Hall.

Emerson, R. M. 1972 "Exchange Theory Part 1: A Psychological Basis for Social Exchange." In J. Berger, M. Zelditch, Jr., and B. Anderson, eds. Sociological Theories in Progress 38–57. Boston: Houghton Mifflin Co.

Epling, W. F., and W. D. Pierce 1988 "Applied Behavior Analysis: New Directions from the Laboratory." In G. Davey and C. Cullen, eds., Human Operant Conditioning and Behavior Modification. New York: Wiley.

Fantino, E., and C.A. Logan 1979 The Experimental Analysis of Behavior: A Biological Perspective. San Francisco: W. H. Freeman.

Herrnstein, R. J. 1961 "Relative and Absolute Response Strength as a Function of Frequency of Reinforcement." Journal of the Experimental Analysis of Behavior 4:267–272.

——1970 "On the Law of Effect." Journal of the Experimental Analysis of Behavior 13:243–266.

——1990 "Rational Choice Theory: Necessary but Not Sufficient." American Psychologist 45:356–367.

Homans, G. C. 1974 Social Behavior: Its Elementary Forms, rev. ed. New York: Harcourt Brace Jovanovich.

Kazdin, A. E. 1994 Behavior Modification in Applied Settings. New York: Brooks/Cole Publishing.

Keller, F. S. 1968 "Good-bye teacher. . ." Journal of Applied Behavior Analysis 1:79–89.

Lloyd, K. E., and M. E. Lloyd 1992 "Behavior Analysis and Technology of Higher Education." In R. P. West and L. A. Hamerlynck, eds., Designs for Excellence in Education: The Legacy of B. F. Skinner 147–160. Longmont, Colo.: Spores West, Inc.

McDowell, J. J. 1981 "On the Validity and Utility of Herrnstein's Hyperbola in Applied Behavior Analysis." In C. M. Bradshaw, E. Szabadi and C. F. Lowe, eds., Quantification of Steady-State Operant Behaviour 311–324. Amsterdam: Elsevier/North-Holland.

——1988 "Matching Theory in Natural Human Environments." The Behavior Analyst 11:95–109.

McLaughlin, B. 1971 Learning and Social Behavior. New York: Free Press.

Pierce, W. D., and W. F. Epling 1983 "Choice, Matching, and Human Behavior: A Review of the Literature." The Behavior Analyst 6:57–76.

——1984 "On the Persistence of Cognitive Explanation: Implications for Behavior Analysis." Behaviorism 12:15–27.

——1999 Behavior Analysis and Learning. Upper Saddle River, N.J.: Prentice-Hall.

——, W.F. Epling, and D. Boer 1986 "Deprivation and Satiation: The Interrelations Between Food and Wheel Running." Journal of the Experimental Analysis of Behavior 46:199–210.

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

——1957 Verbal Behavior. New York: Appleton Century Crofts.

——1969 Contingencies of Reinforcement: A Theoretical Analysis. New York: Appleton Century Crofts.

——1974 About Behaviorism. New York: Knopf.

——1987 "Selection by Consequences." In B.F. Skinner, Upon Further Reflection. Englewood Cliffs, N.J.: Prentice-Hall.

Sunahara, D., and W. D. Pierce 1982 "The Matching Law and Bias in a Social Exchange Involving Choice Between Alternatives." Canadian Journal Of Sociology 7:145–165.

Zeiler, M. 1977 "Schedules of Reinforcement: The Controlling Variables." In W.K. Honig and J.E.R. Staddon, eds., Handbook of Operant Behavior. Englewood Cliffs, N.J.: Prentice-Hall.

Zuriff, G.E. 1985 Behaviorism: A Conceptual Reconstruction. New York: Columbia University Press.

W. David Pierce

BEHAVIORISM

Traditional notions of the mind have tended to treat mental states as "private" and "subjective," not accessible to the public and objective methods of science. With the failure of an "introspectionist" psychology in the early twentieth century, the only recourse seemed to be either to deny that mental states had any role to play in any serious science, or to try to find a way to understand talk of mental states that was entirely objective. The first option is called the "eliminativist" strategy, and Radical behaviorism was a monumental effort to realize it. The eliminativist strategy proposed to explain all human and animal behavior in terms of physically specified stimuli, responses, and reinforcements. It is to be distinguished from the second, "reductionist" strategy, which attempts not to eliminate mental phenomena, but rather to save mental phenomena by identifying them with some or other existing physical phenomena. Analytical behaviorism was the specific reductionist view that mental phenomena could be identified in one way or another with dispositions to overt behavior. Both Radical behaviorism and Analytical behaviorism dominated Anglo-American philosophy, and especially psychology, from roughly 1920 through 1970.

Although the two views are similarly motivated, they are independent. As will be seen in section one, Radical behaviorism is a specific scientific hypothesis, to be assessed according to the usual scientific criteria of how well it predicts and explains its intended range of phenomena. Analytical behaviorism is essentially a semantic, or philosophical hypothesis, to be assessed according to how well it captures the mental notions it purports to analyze (sec. 2). A person could subscribe to one and reject the other: Strict radical behaviorists might be skeptical of semantic proposals of analytical behaviorists; and many analytical behaviorists might reject the scientific proposals of Radical behaviorism.

There is also a third view, methodological behaviorism, according to which the only evidence for any mental phenomena must be behavioral. As a claim about evidence, this is actually independent of both the other views, although it often accompanied them. Indeed, one of the lasting positive contributions of the entire behaviorist movement was a much higher standard of evidence than had been observed previously, discouraging the kind of reliance on empathic intuitions that was characteristic, for example, of clinical psychotherapeutic claims. Unlike Radical behaviorism and Analytical behaviorism, methodological behaviorism survives in some quarters to this day, although some problems for methodological behaviorism are raised at the conclusion of section three.

Radical Behaviorism

the law of effect

Since this is a philosophical encyclopedia, the treatment of Radical behaviorism will perforce be brief (for a more thorough discussion in which references can be found to the experiments cited here see Gleitman et al. 2004, Gallistel 1990, and Rey 1997). However, the treatment of Radical behaviorism is not philosophically irrelevant since a substantial number of twentieth-century philosophical views often relied on it, most famously those of the American philosopher W. V. Quine.

Radical behaviorism emerged from the work of the Edward Thorndike (1874–1949), John Watson (1878–1958), and Ivan Pavlov (1849–1936), receiving its most energetic development in the work of B. F. Skinner (1904–1990) and attaining considerable precision in the work of Clark Hull (1884–1952). It has its source in traditional empiricist theories of the mind, according to which the mind at birth is a tabula rasa, or blank tablet on which experience forms sensory impressions. Ideas are derived from experience and are welded together to form complex ideas by a process of association, which closely tracks the presentation of those experiences in reality. Thus, certain sights, sounds, and tactile sensations become associated in experience to form the idea of a material object, and certain associations of "contiguity, succession and constant conjunction" form the idea of causation (Hume 1734).

This traditional suggestion, though regarded by radical behaviorists as right in spirit, suffered from a major defect—namely, a reliance upon peculiar private entities, ideas, and impressions, which did not seem to radical behaviorists to be proper objects of scientific inquiry. To remedy this situation, they proposed studying not associations among ideas but among physically characterizable stimuli to sense organs and responses of the motor system. The specific law that linked stimuli and responses was Thorndike's Law of Effect, which for purposes of this entry may be stated thus:

The Law of Effect: The probability of a response R following a stimulus S is increased/decreased if pairs 〈R, S〉 have been followed by positive/negative reinforcements, F, in certain patterns (e.g., intermittently) in the past.

For example, should a particular movement like pressing a paw on a lever (=R) when a light is on (=S) be followed intermittently by the presentation to a hungry animal of a food pellet (=F), then the probability of the animal pressing its paw on the lever when the light is on in the future will be increased. Such are rewards. Negative reinforcements are either the absence of positive reinforcements, or actual punishments, which also reinforce, but in the opposite direction: the probability of the R given S is reduced if pairs of S and R have been followed by punishment in the past. Radical behaviorism is essentially the bold hypothesis that all intelligent human and animal behavior can be explained by the Law of Effect.

As Skinner frequently stressed, the Law of Effect is nearly the biological principle of natural selection, extended now beyond the persistence of traits that are genetically inherited to the persistence of acquired behaviors in individual animals. Just as from a random generation of genetic mutations certain ones are selected by virtue of meeting an environmental test of "survival of the fittest," so from an essentially random generation of responses in an animal certain ones are selected by virtue of being reinforced when they occur after certain stimuli. The responses that are selected in this way Skinner (1938) called "operants," since they involved ways that an animal "operated" on an environment that secured reinforcement. This process of "operant conditioning" was Skinner's distinctive contribution over "classical conditioning," where the response was elicited (e.g., salivation by hunger in Pavlov's dogs), rather than being spontaneously emitted.

How could such a simple law as the Law of Effect possibly stand a chance of explaining the full range of animal behavior? The central idea was an extension of the associationist strategy of building complex ideas from simpler ones, only now it was a matter of building not complex ideas, but complex responses. These could be built up out of simpler responses by "response chaining," whereby stimuli associated with a reward themselves become ("secondary") reinforcers, and so available for the conditioning of further responses. Thus, a pigeon conditioned to peck a lever on hearing a bell could now be conditioned by the sound of the bell itself to produce further responses given further stimuli, say, doing a little dance on seeing a red light, which is then followed by the bell, which is then followed by food if the pigeon pecks again at the lever. Discrimination of complex stimuli would similarly be built from discrimination of simpler stimuli, through either a chain of discriminations of simpler stimuli, or by "stimulus generalization," whereby novel stimuli are treated as "of the same kind" as earlier ones.

The Law of Effect is likely true of some animal behavior. Skinner achieved remarkable successes using it to train animals to engage in all manner of curious behavior: for example, rats to run mazes, pigeons to play Ping-Pong, and pigs to push shopping carts around supermarkets. And the Law of Effect seems to play a role in explaining a variety of persistent behavioral patterns, such as gambling and drug addiction, as well as in extinguishing them, as in "behavior modification therapy." For the purposes of this entry, the issue is not whether such applications occur or are a good idea, but whether they offer a theoretically adequate paradigm for understanding the full range of intelligent animal behavior.

inadequacies of the law of effect

Problems with the Law of Effect emerge in the first instance from the radical behaviorist experiments themselves. Contrary to popular belief, it is not only human behavior that resists radical behavioristic explanation; the theory does not even really work for the rats. The main problem is that the probability of a response can be increased in ways other than by the Law of Effect. There are at least four classes of phenomena that the law has trouble explaining: latent learning, passive learning, spontaneous alteration, and improvisation.

Latent learning occurs when an animal learns without reinforcement. Rats that were well sated with, for example, food and water were allowed to run around in a maze for ten days without any reward, sometimes being placed in the maze at arbitrarily different points. Subsequently, when they were hungry again they were introduced into the maze and were able to find the food much faster than rats not previously exposed. Similarly, Harry Harlow showed that monkeys presented with a complex hinge, requiring the undoing of several pins and bolts to free it, learned to undo it with no special reward other than "the fun of it." Further, indigo buntings learn something about the position of the stars while still in the nest, despite not using this information for navigation (and so, a fortiori, not for any reward) until they are much older. In all of these cases the probability of the animal producing the appropriate response was greater than that of animals that had not been previously exposed to such stimuli, but without any history of reinforcement. In a related vein, passive learning occurs when an animal learns without antecedently producing the requisite response. Thus, rats can learn a maze merely by being pulled through it in a transparent trolley car, not executing anything like the responses that will take them through the maze when they are tested later.

Not only can rats learn without reinforcement or response, they can sometimes respond in ways that defy their conditioning history. In "spontaneous alteration," an animal actually avoids emitting the response that has recently been reinforced. After having found food at a particular location, for example, hummingbirds will go somewhere else to find more food. Rats presented with a number of paths of equal length to a goal will vary their routes, although invariably in ways that advance their approach to the goal. The phenomenon is most dramatically displayed by rats in a "radial maze," consisting of eight pathways radiating out in all directions from a central location, with baits placed at the end of each arm. The Law of Effect should predict that the rats should return to an arm in which they have found food. What they do instead, however, is to avoid an arm they have already visited until they had—at random—visited all the others. That is (as we might put it mentalistically), they seem not to be matching responses to stimuli, but "keeping track" of "where the baits are," and, knowing they had consumed one, no longer "expected" it to be there. The Law of Effect seems not only inadequate to account for such cases; it actually seems to be disconfirmed by them

Animals also produce appropriate behaviors that have not even previously been produced, much less reinforced. Thus, rats trained to take a circuitous route to a goal box will immediately take a shortcut if it is made available. Indeed, animals apparently refuse to be tied to specific physical responses: Rats will swim a flooded maze after being taught to run it, and—moving to the wild, outside the confines of a structured maze—desert ants will forage in a winding path up to one hundred meters from their nests, and then, once they find food, will take a beeline home.

Passing beyond issues of navigation, it has been noted with regard to latent learning that monkeys presented with a novel, complex hinge, figure out how to undo several pins and bolts to free it. Köhler demonstrated even more remarkable improvisation in chimpanzees: They would use sticks as rakes to secure food that was outside a fence; they would then use these sticks as poles, which they would climb up in order to snatch food that was out of reach, grasping the food just as the stick toppled over. In all of these cases, the responses—that is, the sequence of muscular motions required to execute the acts—are by no means physically type-identical between prior and test trials. So the animals must have learned something other than merely to repeat certain physically typed responses.

Of course, these inadequacies with the Law of Effect become even more glaring in the human case. Picking up on an example of Skinner's (1957, p. 38), Daniel Dennett (1975) provides an apt and amusing discussion of the difficulties besetting a radical behaviorist attempting to explain why someone mugged in New York hands over his wallet: Why doesn't the person instead do any number of things that were more likely to have been previously reinforced with the stimulus "Your money or your life," such as giggling, or yawning? Of course, it is not impossible that there is a story of prior threat stimuli and responses of the requisite sort. But the burden is squarely on the radical behaviorist to supply it.

Radical behaviorists, of course, did not take challenges to the inadequacies of the Law of Effect lying down. They often made ingenious replies to them involving elaborate emendations of the theory—for example, by Clark Hull (1943). But these emendations were then subject to further tests, showing animals to be more ingenious than the Law of Effect allowed. A consensus began to emerge that what animals learn is not any mere sequence of responses to stimuli, but rather to the development of what Edward Tolman called an "internal map" (1948). Such talk of "insight" and "maps" of course, begins to imperil any eliminativist ambitions of Radical behaviorism: such a map would be an inner representation, involving an internal mental state.

structured responses and language

An important problem in principle for Radical behaviorism was raised by Karl Lashley (1951): Serial responses like those involved in tying shoes or riding a bicycle seemed to be structured in a way that it did not seem possible to explain by local response-chaining alone. A domain of behavior that exhibits particularly striking structure is language. Skinner (1957) tried to sketch an account of linguistic behavior, but it was soon subject to a devastating review by the then young linguist Noam Chomsky (1964). Among other things, he pointed out:

1. along lines indicated by Lashley, language is structured in units that cannot be captured by response chaining. For example, a sentence of the form "Either … or …," or "If … then … " can involve waiting indefinitely for novel items to be inserted in the blanks;
2. language is creative : most of the sentences people encounter and produce are constantly novel —it is why people bother to converse, read, and write—all contrary to the Law of Effect's commitment to a prior history with the stimuli and responses;
3. language is productive : in grasping a grammar, even small children know how to produce a potential infinity of novel, structured sentences, as in "This is the house that Jack built," "This is the rat that lived in the house …," "This is the cat that chased the rat …," without any history of conditioning each component in this way; indeed:
4. the complex set of rules that constitute the grammar is acquired effortlessly by practically all human children by the age of three, without (and sometimes despite) any efforts at explicit instruction.

(For more detailed discussion see Chomsky 1972 and Pinker 1994).

Although Chomsky's review was (to many minds) a definitive blow by itself, what really led to the end of Radical behaviorism was the spectacular positive research program that he and others (e.g., Fodor 1968, 1975) had begun to develop, what has come to be called the cognitive revolution, associated with computational-representational theories of mental processes.

Often recognizing the difficulty of avoiding mentalisms in the explanation of animal behavior, radical behaviorists sometimes allowed mentalisms to creep into their explanations, postulating "exploratory" and "curiosity" drives, or "drives to perceive" or "know." Of course, if the theory was to remain true to its goal to avoid reference to subjective mental states that it regarded as unscientific, it would be obliged to define these postulations in terms of overt behavior. It was in this way that Radical behaviorism invited Analytical behaviorism, to which we now turn.

Analytical Behaviorism

Analytical behaviorism was motivated by two related philosophical trends of the twentieth century that persist into the twenty-first century: the well-known verifiability theory of meaning (or verificationism ) and the less well-known doctrine that might be called irreferentialism. Because the latter serves as something of a background for the former, it will be considered first.

irreferentialism

Irreferentialism is a novel suggestion that arose from Bertrand Russell's (1905) famous theory of definite descriptions, according to which expressions like "the present king of France" should not be construed as referring to any (in this case) nonexistent entity, but as rather shorthand for some logically complex expression, only some of the most basic parts of which manage to refer. Perhaps the most obvious deployment of such a strategy is the in the case of a sentence such as "The average American family has 2.5 children," which, of course, does not entail that there is some family somewhere in America that has a half of a child. A proper analysis of the grammar of the claim reveals that it is simply a way of expressing the ratio between American families and their children.

The view begins to be applied as a claim about mental expressions in the work of the later Wittgenstein (1953) and Gilbert Ryle (1949). They argued that philosophers too often think about the phenomena that people introspect in their "inner mental worlds" on the model of the objects in the familiar "outer" one. The temptation to this analogy arose, Wittgenstein and Ryle claimed, from an excessively referential conception of the functioning of the human mental vocabulary, treating words like "belief," "thought," and "sensation" as referring to "inner," "private" objects, in the way that words like "cat" and "rock" refer to outer, public ones. It is not that, like "Zeus," they do not happen to refer to anything; rather, like "the average American," they do not even purport to refer to anything. The view is perhaps best known from Ryle's attack on the idea of the "ghost in the machine": A mind is not some sort of thing that could be a ghost, or any other thing. Not surprisingly, this irreferentialism was often associated with an antipathy one finds in Wittgenstein (1953) and Ryle (1949) toward a psychology that suggests a "promise of hidden discoveries yet to be made of the hidden causes of our actions and reactions" (Ryle 1949, p. 325).

Irreferentialism is an essentially negative thesis about the analysis of mental terms. Understandably, many people might want to hear something more positive: if the analysis of mental terms does not involve the postulation of mental entities, what does it involve? For Wittgenstein and his followers, in particular, this question (like, in their view, most philosophical questions) was the wrong one to ask: it exhibited a somehow inappropriate "craving for generality" about the nature of thought and language. That may in the end be so, but many wanted to see a greater effort made toward some systematic account than he and his followers provided. The use of mental language does not seem entirely capricious and chaotic, and, if it is not, then it is not unreasonable at least to ask what the principles might be that guide its use.

verificationism

According to verificationism, the meaning of a claim consists in the method by which it could be tested (see Ayer 1952 for a classic statement). For example, claims about something's being an acid might be defined in terms of its turning litmus paper red. Or claims about the existence of material objects might be analyzed as logical construction of claims about those sense experiences that people ordinarily take to confirm such claims (e.g., that people would have certain experiences of color, shape, and resistance to touch). Hypotheses such as those of the possibility of human lives being a dream, or other people having radically different mental lives were to be ruled out as "meaningless" if there really were in fact no evidence in principle that could make a difference to their truth or falsity.

There are myriad problems with verificationism: It is by no means obvious how to apply it to the claims of logic, mathematics, ethics, or aesthetics, or even to itself (what is the test for assessing where it is true?). Even in the supposed parade cases of natural science verificationism did not fare well: Scientists often do not know how to seriously test a hypothesis (as in contemporary string theory in physics) and often change their tests as their theories evolve (as new tests are devised for a disease). But the most serious problem is confirmation holism, or the fairly obvious observation that claims are not tested by experiment individually, but only as parts of whole theories (see Quine 1960). As will be seen, Analytical behaviorism offered a vivid case in point.

analytical behaviorist proposals

Analytical behaviorism was largely motivated by verificationism and the observation that the vast majority of human mentalistic claims are tested by observing overt behavior (of course, this does not seem to be true in the case of first-person reports, which were always a problem for Analytical behaviorism, although these represented a small minority of claims). Moreover, it did seem that those ascriptions were by and large indifferent discoveries that might be made about the actual physical aetiology of mental life. If one were to open up the heads of familiar people and discover that they were empty or full of sawdust, one would not conclude that these familiar people did not have the mental states that seem to be constituted by the familiar behavior observed. Consequently, it seemed reasonable to suppose that mental claims should be understood as equivalent to various sorts of dispositional or conditional claims about how an agent would behave if she were in such and such circumstances. One particular model that impressed behaviorists was that of dispositional claims that arise elsewhere: "Salt is soluble" presumably means something like, "If salt is put into water in certain normal conditions, then it dissolves"; "Glass is fragile," something like, "If struck in normal circumstances, it breaks." Analogously, wanting something should be taken to mean something like "trying to get it, if the occasion were to arise."

Successfully spelling out the appropriate dispositions in the case of mental terms turned out, however, to be none too easy. Ryle was never precise, but he offered a strategy, exemplified by the following characterization of belief:

To believe that the ice is dangerously thin is to be unhesitant in telling oneself and others that it is thin, in acquiescing in other people's assertions to that effect, in objecting to statements to the contrary, in drawing consequences from the original proposition, and so forth. (Ryle 1949, 134–135)

action vs. "colorless movement"

A formidable problem arises, however, as soon as one considers the "behavior" on which people normally rely, namely of distinguishing actions from mere movement : To take a famous example from Wittgenstein, it is the difference between raising one's arm and one's arm rising. The rising of an arm might occur as a result of, say, some machine moving the arm up and down; it is only the raising of an arm if it was the result of the person whose arm it is intending to raise it. Ryle may think that he is describing mere behavior in talking about someone being "unhesitant" and "acquiescing," "objecting" to certain "assertions," but a moment's reflection reveals these as only slightly covert mentalisms: hesitation, acquiescence, and the possible involvement of any of an indefinite variety of bodily movements (or none); all that is crucial is that whatever the agent does or does not do is a result of a certain psychological attitude.

This point was often most seriously missed by the radical behaviorists who, as has been noted already, often resorted to mentalisms to deal with the apparent counterexamples to their Law of Effect. Thus, Skinner wrote:

The artist … is reinforced by the effects his works have upon … others … [his] verbal behavior … reach[ing] over centuries or to thousands of listeners or readers at the same time. The writer may not be reinforced often or immediately, but the reinforcement may be great. (Skinner 1957, pp. 206, 224)

But, as Chomsky (1964) noted, the term reinforcement here has degenerated to only a ritual function, being used as a cover term for "X wants Y," "X likes Y," "and X wishes that Y were the case."

insuperable problems

For every thought experiment arguing for Analytical behaviorism there are compelling ones against it as well. Consider not only people with sawdust heads, but people who turn out to be robots cleverly controlled by radio waves produced by some ingenious scientists at MIT: Such creatures would seem to have no more of a mental life than do marionettes. Or consider a race of "Super-Spartans" who, as matter of training and principle, refuse to flinch or complain in response to even the most excruciating pain and are inarticulate about an enormous range of their psychological repertoire (Putnam 1975). Surely it is possible that these Super-Spartans have by and large the full range of psychological states of the more expressive and articulate.

All of these objections become more evident when one considers an underlying technical difficulty noticed by Roderick Chisholm (1957): Every effort to define most mental states by behavior seems to require citation of other mental states. Typically, any particular mental state causes a particular behavior only in conjunction with (an often large number of) other mental states. Beliefs, hopes, and expectations issue in behavior only in conjunction with (at least) desires; desires issue in behavior only in conjunction (at least) with beliefs and expectations. To take a proposed example from Tolman, suppose a person tried to define a rat's expectation that there is food at L in terms of the rat's moving toward L: This only if the rat wants food; and the rat's wanting food can be defined in terms of its moving toward L only if it expects there is food at L. Insofar as this is true, the prospects of a definition of a single informational or single directional state in terms of behavior seem dim. This problem is an instance of the aforementioned confirmation holism emphasized by Quine. Indeed, a philosophically influential (and disconcerting) way of understanding this and related difficulties with Analytical behaviorism is provided by Quine's (1960, ch. 2) "thesis of the indeterminacy of translation," according to which there is no fact of the matter about the content of mental states, a thesis that has influenced later philosophers such as Donald Davidson, David Lewis, and Dennett.

Methodological Behaviorism

In the twenty-first century few, if any, philosophers or psychologists would be prepared to defend either Radical behaviorism or Analytical behaviorism. However, there is a weaker view that survives, called "methodological behaviorism," according to which the only permissible evidence for a psychological claim can be behavioral. It is not, like Radical behaviorism, an explanatory scientific hypothesis, but neither does it, like Analytical behaviorism, offer analyses of mental terms, although it is motivated by vaguely verificationist concerns like those that motivated Analytical behaviorism. Methodological behaviorism is perhaps best expressed by Wittgenstein's famous dictum, "An inner process stands in need of outward criteria," (1953, sec. 580) but without any of the analytical behaviorist commitment to defining an inner process in terms of some specific criteria. It has most recently been defended by Dennett (1993), who describes its motivation as not a "village" but an "urbane verificationism" that is merely trying to avoid "epiphenomenalism, zombies, conscious teddy bears, [and] self-conscious spiders" (1993, p. 461). Indeed he "unhesitatingly endorse[s] the claim that necessarily, if two organisms are behaviorally exactly alike, they are psychologically exactly alike" (1993, p. 922).

For all methodological behaviorism's urbanity, however, it is hard to find a convincing argument for it. Why shouldn't psychologists avail themselves of evidence that may go beyond ordinary overt behavior, as they indeed seem increasingly to do when they investigate the finer structure of the brain? Consider, for example, the nice case Dennett (1991, pp. 395–396) discusses of the familiar plight of the adult beer-drinker who wonders whether in coming to like it since childhood, it is his experiences or his preferences that have changed. It can seem obscure what further considerations should settle the matter, and it is not implausible to suppose that current behavioral discriminations or even introspection would not suffice. Dennett concludes that that there is in such a case "no fact of the matter" about "the way the beer tastes" to such a person.

But suppose it turns out that children have more taste buds than adults. One might have independent evidence that both children and adults have the same preferences for bitter titillation, but that consequently children reach a painful threshold sooner with the same quantity of a bitter substance. It tastes differently because, arguably, more intense sensation is caused by their tongues and/or gustation subsystems. However, such cases would clearly transcend mere behavioral evidence.

So, in the end, even methodological behaviorism seems problematic given the increasingly rich conceptual and evidential resources of cognitive science, and especially of a computational/representational theory of thought. Behaviorism in all its forms seems a heroic theory that was ultimately defeated by the high standards of theory and experimentation that it encouraged. Eliminativist strategies survive in ambitions to replace mental talk by neurophysiological descriptions, and reductionist strategies abound, along either neurophysiological lines or computational ones. But the effort to replace mental talk with behavioral talk, or reduce it to it, can safely be said to have passed with the twentieth century, in which it first appeared.

See also Chomsky, Noam; Fodor, Jerry A.; Functionalism; Mind-Body Problem; Physicalism; Quine, Willard Van Orman; Reductionism in the Philosophy of Mind; Verifiability Principle.

Bibliography

Ayer, A. Language, Truth and Logic. New York: Dover, 1952. A classic statement of the "Verificationist Theory of Meaning," which provided the general semantic view underlying Analytical behaviorism.

Chisholm, R. Perceiving: A Philosophical Study. Ithaca, NY: Cornell University Press, 1957.

Chomsky, N. Language and Mind. New York: Harcourt Brace Jovanovich, 1972. Chomsky's earliest and most accessible statement of the relation of his theory of grammar to theories of the mind generally.

Chomsky, N. "Review of Skinner's Verbal Behavior." In The Structure of Language: Readings in the Philosophy of Language, edited by J. Fodor and J. Katz, 547–578. Englewood Cliffs, NJ: Prentice Hall, 1964. The devastating review of Skinner's effort to incorporate linguistic behavior into Radical behaviorism.

Dennett, D. Brainstorms. Cambridge, MA: MIT Press, 1975. Several essays ("Skinner Skinner," "Why the Law of Effect Won't Go Away") provide excellent discussions of the attractions and limitations of Radical behaviorism.

Dennett, D. Consciousness Explained. New York: Little Brown, 1993. A recent defense of methodological behaviorism (which he calls "urbane verificationism").

Fodor, J. The Language of Thought. New York: Crowell, 1975. The classic statement of the computational/representational theory of thought that, he argues, is presupposed by virtually all work in cognitive and perceptual psychology.

Fodor, J. The Modularity of Mind: An Essay on Faculty Psychology. Cambridge, MA: MIT Press, 1983. The classic statement of the now highly influential view of perception and language processing as consisting of computational "modules."

Fodor, J. Psychological Explanation: An Introduction to the Philosophy of Psychology. New York: Random House, 1968. An early, powerful philosophical critique of both Radical behaviorism and Analytical behaviorism.

Gallistel, C. The Organization of Learning. Cambridge, MA: MIT Press, 1990. An important non-behaviorist, computational theory of animal navigation, bringing together extensive studies of animals in the wild.

Gleitman, H., A. Fridlund, and D. Riesberg. Psychology. 6th ed. New York: Norton, 2004. An excellent, up-to-date text in psychology. Chapter four provides a detailed account of Radical behaviorism.

Hull, C. Principles of Behavior: An Introduction to Behavior Theory. New York: Appleton-Century-Crofts, 1943. A serious, concerted effort to state the laws of behavior in terms of "colorless movement" in ways designed to accommodate many of the experimental problems Radical behaviorism faced.

Hume, D. A Treatise of Human Nature, (1739), edited by L. A. Selby-Bigge. 2nd edition revised by P. H. Nidditch. Oxford: Clarendon Press, 1975. The classic statement of an associationist psychology, of which Radical behaviorism was an instance.

Lashley, K. S. "The Problem of Serial Order in Behavior." In Cerebral Mechanisms in Behavior, edited by L. A. Jeffress, 112–136. New York: Wiley, 1951. Widely regarded as raising a crucial problem for Radical behaviorism by calling attention to highly structured behaviors that could not be the result of mere response chaining.

Pinker, S. The Language Instinct: How the Mind Creates Language. New York: Harper and Row, 1994.

Putnam, H. "Brains And Behavior." In Mind, Language And Reality: Philosophical Papers. Vol. 2. Cambridge, U.K., and New York: Cambridge University Press, 1975, 325–341.

Quine, W. V. Word and Object. Cambridge, MA: MIT Press, 1960. Chapter two presents his influential discussion of the "indeterminacy of translation," which he draws as an interesting consequence of Radical behaviorism.

Rey, G. Contemporary Philosophy of Mind: A Contentiously Classical Approach. Oxford: Blackwell, 1997. Chapters four and five present detailed discussions of Radical behaviorism and Analytical behaviorism along lines of the present article. Chapters seven and ten present arguments against methodological behaviorism (called "superficialism" there).

Russell, B. "On Denoting" Mind 14 (1905): 479–493.

Ryle, G. The Concept Of Mind. London: Hutcheson, 1949.

Skinner, B. F. The Behavior of Organisms: An Experimental Analysis. New York, Appleton-Crofts, 1938. The official statement of Skinner's famous version of Radical behaviorism.

Skinner, B. F. Verbal Behavior. New York: Appleton-Century-Crofts, 1957. Skinner's effort to provide a radical behaviorist framework for understanding language.

Tolman, E. "Cognitive Maps in Rats and Men." Psychological Review 55 (1948): 189–208.

Georges Rey (2005)

BEHAVIORISM

Most generally, behaviorism is a viewpoint that takes psychological phenomena as physical activity rather than as belonging to a special domain of mental events. For a behaviorist, then, psychology is the study of behavior and its physical, mainly environmental, determinants rather than of the nature of experience or of mental process. Behaviorism originated in natural-science traditions of the late nineteenth century, and precursors of its methods and concepts developed at the turn of the century in the work of E. L. Thorndike and Russian physiologist I. P. Pavlov, as well as of several other psychologists and physiologists (Day, 1980; Herrnstein, 1969).

But behaviorism as a distinct viewpoint came to be recognized with the publication of American psychologist John B. Watson's article "Psychology as the Behaviorist Views It" (1913). Identification of behaviorism with the controversial Watson persists despite the fact that it developed into several distinct traditions that bear only a family resemblance to Watson's views and to each other (Malone, 1990; Zuriff, 1985). The leading contemporary behaviorist position derives from the work of B. F. Skinner, which differs from other behaviorisms in its detailed account of verbal functioning and in its inclusion of activities such as thinking and feeling as behavior to be accounted for, while maintaining a primary focus on behavior-environment relations rather than upon processes inferred as underlying those relations.

Behaviorism originated in opposition to an orthodox psychology that attempted to analyze conscious experience by focusing upon reports by observers who were trained to examine their own mental functions through techniques of introspection. Watson boldly rejected this, asserting that behavior, per se, is the proper domain of psychology. For Watson, prediction and control of overt behavior, rather than introspection of mental processes, formed the basis for an objective, scientific psychology. Behavior was to be analyzed into stimulus-response (S-R) units without appeal to hypothetical activities of brain or mind. The units could be of widely varying size, from the relatively molecular eyeblink elicited by a flash of light to the more "molar" shopping trip as response to an empty cupboard. Watson emphasized the continuity between human and nonhuman species, and he stressed the importance of learning, in animals as well as in humans, as the fundamental basis for understanding psychological process.

A neobehaviorism that came to the fore in the 1930s, that of Clark L. Hull and his student Kenneth Spence, dominated until mid-century. Like Watson, Hull described behavior as composed of S-R units, but whereas Watson had presented S-R analyses as adjustable in scale, the Hull-Spence approach focused on molecular building blocks that were described as forming chains of connecting events between environmental stimuli and observed behavior. These mediating events included hypothetical (but presumably physical) stimulus traces, covert responses, and response-produced stimuli. Learned S-R units were called habits. Hull contrived an elaborate theory whose theorems and postulates, presented in geometer's style, were concerned with the formation of habit strength and with the mechanistic conversion of habit strength into overt action. The theory was published as essentially complete in 1943. Although highly touted, it proved ponderous, with numerous terms that were difficult to evaluate; it fell of its own weight within a decade. Nevertheless, Hullian students gained dominant positions within academic psychology, and elements of that approach can be discerned to this day in theorizing that rests on the metaphor of mechanical associative connections. Hull's emphasis on formal hypothesis testing, directed at hypothetical constructs that are anchored to observable events as specified by operational definitions, also survives as a "methodological behaviorism" (Skinner, 1945) that has permeated much of psychology.

A counterpoint to Hull's views in the 1930s and 1940s was provided by Edward C. Tolman, who attempted to include purposive, intentional language within a behavioristic system. He invoked terms like purpose, expectation, and cognition to capture the larger-scale, goal-oriented "molar" organization of behavior. Tolman asserted that these terms need not imply anything nonphysical or mentalistic; indeed, he employed them in accounting for behavior of laboratory rats as well as of humans. But Tolman undermined such disclaimers by characterizing his view as S-O-R theory, with the "O" denoting a special role for processes within the behaving organism. The learning of complex relationships, often characterized as "cognitive maps," was said to mediate between environment and behavior. Critics of Tolman's account suggested that it left the organism "buried in thought." To the extent that he addressed the sources of action, Tolman placed them within the organism, which tended to link his account with traditional mentalistic explanations of action. Thus it is not surprising that Tolman's inclusion of intentional language never was accepted by the broader behavioristic community.

B. F. Skinner also departed from the S-R behavioral mainstream of the 1930s and 1940s, but in different ways. He rejected mentalistic terms as "misleading fictions" while including the relationships that were Tolman's primary concern. Skinner's first conceptual innovation was to reformulate the reflex; he described this simplest unit of behavior not as stimulus-response connection but as directly observable abstraction, a correlation between classes of stimuli and classes of responses. Then he distanced his theory further from mediational notions of mechanism and associative connection by delineating non-reflexive behavioral units that he called operants. Operants act upon the environment; they are selected by their consequences through processes denoted as reinforcement, punishment, and extinction. Operants can range from small to large, and are defined by the consequences that shape or maintain them but also by the contexts within which the selecting consequences have occurred. The result is a three-term relationship composed of classes of responses, consequences, and discriminative stimuli.

Operant behavior often is characterized in ordinary language as intentional and purposive, thus having the "molar" characteristics that were Tolman's primary concern. But the traditional appeal to mentalistic intention is replaced by environment-based selection in this account of action, just as in Darwinian biology natural selection replaces divine intention in the account of new species. Learning of new behavior is readily demonstrated by rapidly shaping new patterns through differential reinforcement and through gradual fading of discriminative stimuli. In later work, Skinner (1984) described selectionist principles as applying to behavior patterns at the evolutionary level as well as at the level of cultural practice, giving accounts with close affinity to contemporary work in anthropology (e.g. Lloyd, 1985) and biology (Dawkins, 1982; Smith, 1986).

While his theory also included other principles, Skinner emphasized reinforcement as a basic relation, examining its properties and its broad implications. Empirically, he asked what would happen if only some occurrences of a response are reinforced; he devised schedules of reinforcement to explore the many ways in which this can happen and their effects on rates, patterning, and persistence of behavior. Contemporary research has extended this to examine issues such as the conditions of self-control and preferences among schedules that are relevant to microeconomics (e.g., Rachlin, 1989) and to biological theories of foraging (e.g., Fantino and Abarca, 1985). Interpretatively, Skinner addressed the functional characteristics of verbal behavior, describing how an individual affects the behavior of others and how others teach the individual's verbal discriminations (Skinner, 1957). His approach initially was not welcomed by linguists, but later developments in linguistics are more congenial to it (Andresen, 1990). The analysis includes activities like thinking, feeling, and even introspecting as behavior to be accounted for rather than as special bases for explaining overt action. It asserts that individuals know their private thoughts and feelings less well than they know external events, because the world cannot as accurately teach individuals to discriminate the former (Skinner, 1963). This provocative position gains independent support from the philosophies of Ryle (Schnaitter, 1985) and Wittgenstein (Day, 1969).

Skinner also addressed ethical and social issues in light of reinforcement-based principles, speculatively in Walden Two, a utopian novel that sketches an experimental approach to communal living, and analytically in essays such as "The Ethics of Helping People" (Skinner, 1978), which asserts that human rights properly concern empowerment of effective action rather than access to things or services. Extensive discussions of these and other implications of reinforcement theory are provided by Skinner (1971, 1974), and by Catania and Harnad (1988). Contemporary behavioral research related to language emphasizes relationships between verbal and nonverbal behavior (Cerutti, 1989; Hayes, 1989) and issues such as the nature and origins of symbolic functioning (Sidman, 1986).

Of contemporary approaches, the most distinctly behavioral one is behavior analysis. Extending from Skinner's work, it differs philosophically and conceptually from other behaviorisms as well as from mainstream psychology (Lee, 1988). Its pragmatic contributions have proved effective in such diverse settings as health-maintenance programs concerned with weight control, smoking, and wearing of automobile seat belts; "frequent flier" marketing techniques launched by airlines; techniques for basic research on drug addiction as well as for its treatment; educational techniques of documented effectiveness for handicapped and disadvantaged, as well as for mainstream, children (Becker, 1978; Wolf et al., 1987); and innovative formats for personalized instruction at the college level (Keller, 1977). Contemporary behaviorists are represented by professional organizations that include several thousand researchers, scholars, and practitioners (Thompson, 1988) whose work is represented by more than a score of primarily behavioral journals (Wyatt et al., 1986). Thus, behaviorism has extended well beyond, while continuing an appositional role within, the specialized field where it began.

See also:OPERANT BEHAVIOR; SKINNER, B. F.; TOLMAN, EDWARD C.

Bibliography

Andresen, J. T. (1990). Skinner and Chomsky thirty years later. Historiographia Linguistica 17, 145-165.

Becker, W. C. (1978). The national evaluation of follow-through: Behavior theory-based programs come out on top. Education and Urban Society 10, 431-458.

Catania, A. C., and Harnad, S. (1988). The selection of behavior, the operant behaviorism of B. F. Skinner: Comments and consequences. New York: Cambridge University Press.

Cerutti, D. T. (1989). Discrimination theory of rule-governed behavior. Journal of the Experimental Analysis of Behavior 51, 257-276.

Dawkins, R. (1982). The extended phenotype. San Francisco: Freeman.

Day, W. F. (1969). On certain similarities between the Philosophical investigations of Ludwig Wittgenstein and the operationism of B. F. Skinner. Journal of the Experimental Analysis of Behavior 12, 489-506.

—— (1980). The historical antecedents of contemporary behaviorism. In R. W. Rieber and K. Salzinger, eds., Psychology: Theoretical-historical perspectives, pp. 203-262. New York: Academic Press.

Fantino, E., and Abarca, N. (1985). Choice, optimal foraging, and the delay-reduction hypothesis. Behavioral and Brain Sciences 8, 315-362.

Hayes, S. C., ed. (1989). Rule-governed behavior: Cognition, contingencies, and instructional control. New York: Plenum.

Herrnstein, R. J. (1969). Behaviorism. In D. L. Krantz, ed., Schools of psychology: A symposium, pp. 51-68. New York: Appleton-Century-Crofts.

Hull, C. L. (1943). Principles of behavior. New York: Appleton- Century-Crofts.

Keller, F. S. (1977). Summers and sabbaticals: Selected papers on psychology and education. Champaign, IL: Research Press.

Lee, V. (1988). Beyond behaviorism. Hillsdale, NJ: Erlbaum.

Lloyd, K. E. (1985). Behavioral anthropology: A review of Marvin Harris's Cultural materialism. Journal of the Experimental Analysis of Behavior 43, 279-287.

Malone, J. C. (1990). Theories of learning: A historical approach. Belmont, CA: Wadsworth.

Rachlin, H. (1989). Judgment, decision, and choice: A cognitive/behavioral synthesis. New York: W. H. Freeman.

Schnaitter, R. (1985). The haunted clockwork: Reflections on Gilbert Ryle's The concept of mind. Journal of the Experimental Analysis of Behavior 43, 145-153.

Sidman, M. (1986). Functional analysis of emergent verbal classes. In T. Thompson and M. D. Zeiler, eds., Analysis and integration of behavioral units, pp. 213-245.

Hillsdale, NJ: Erlbaum. Skinner, B. F. (1938). The behavior of organisms: An experimental analysis. New York: Appleton-Century-Crofts.

—— (1945). The operational analysis of psychological terms. Psychological Review 52, 270-277, 291-294.

—— (1948). Walden two. New York: Macmillan.

—— (1957). Verbal behavior. New York: Appleton-Century- Crofts.

—— (1963). Behaviorism at fifty. Science 134, 566-602.

—— (1971). Beyond freedom and dignity. New York: Knopf.

—— (1974). About behaviorism. New York: Knopf.

—— (1978). Reflections on behaviorism and society. Englewood Cliffs, NJ: Prentice-Hall.

—— (1984). Selection by consequences. Science 213, 501-504.

Smith, T. L. (1986). Biology as allegory: A review of Elliott Sober's The nature of selection. Journal of the Experimental Analysis of Behavior 46, 105-112.

Thompson, T. (1988). Benedictus behavior analysis: B. F. Skinner's magnum opus at fifty. Contemporary Psychology 33, 397-402.

Tolman, E. C. (1932). Purposive behavior in animals and men. New York: Appleton-Century-Crofts.

Watson, J. B. (1913). Psychology as the behaviorist views it. Psychological Review 20, 158-177.

—— (1919). Psychology from the standpoint of a behaviorist. Philadelphia: J. B. Lippincott.

Wolf, M. M., Braukmann, C. J., and Ramp, K. A. (1987). Serious delinquent behavior as part of a significantly handicapping condition: Cures and supporting environments. Journal of Applied Behavior Analysis 20, 347-359.

Wyatt, W. J., Hawkins, R. P., and Davis, P. (1986). Behaviorism: Are reports of its death exaggerated? The Behavior Analyst 9, 101-105.

Zuriff, G. E. (1985). Behaviorism: A conceptual reconstruction. New York: Columbia University Press.

Philip N.Hineline