Sabtu, 31 Maret 2012

The principle of operant conditioning from the laboratory to real life

The principle of operant conditioning
As Skinner argued throughout his work it is essential to any possible adequate explanation of behaviour not to rely on mentalistic terms. Any explanation based on mentalistic terms, in fact, presupposes the rationality of the agent. 
Citing reasons, intentions, beliefs, etc. does not provide an explanation of what makes behaving that organism according with those reason, intention, beliefs, in other world why the behaviour of the agent is rational and what makes his behaviour so adequate to the environment (Palmer, 2009).
Inevitably a scientific account of behaviour will replace with mechanistic explanations the intentional terms usually adopted. “Science seems to be inevitably iconoclastic. It usurps the place of the explanatory fictions which men have invented as pre-scientific devices to account for nature (Skinner, 1957, p. 234). The Copernican system, astronomy, Darwinism, chemistry, anthropology, carry on Skinner, shows that inevitably “as science advances, it strips men of fancied achievements”. “It was inevitable” concludes “that psychology should enter these lists”.(Skinner, 1957).
It is easy to see that the burden of dispensing behavioural explanations with mentalistic terms (and in this way making psychology enter the list), is borne by the principle of operant conditioning. As many commentators point out, its role for psychology is analogous of that played by the principle of natural selection for biology. The principle of natural selection has been so powerful and productive for such a long time because it dispense theory of evolution with the appeal to finalistic concepts (Fodor & Piattelli-Palmarini, 2010, Dennett, 1978).
Darwin explains a world of final causes and teleological laws with a principle that is, to be sure, mechanistic but - more fundamentally - utterly independent of 'meaning' or 'purpose'. It assumes a world that is absurd in the existentialist's sense of the term: not ludicrous but pointless and this assumption is a necessary condition of any non-question-begging account of purpose” (Dennett, 1978, p. 73). The field of application is different (phenotypic characters of organisms for the evolutionary theory, behaviours for the principle of operant conditioning), but the “two theories are virtually identical: they propose essentially the same mechanisms to compute essentially similar functions under essentially identical constraints“ ( Fodor & Piattelli-Palmarini, 2010, p. 3).
The operant conditioning theory sees an organism as a random generator of operants. Among these random behaviours reinforcers select the adaptive ones, whereas the maladaptive undergo a process of extinction (Fodor & Piattelli-Palmarini, 2010, Dennett, 1978). According to the principle behaviours, like species, are selected or extinguished by their adequacy to the environment.
Skinner explicitly holds this similarity with the principle of natural selection as an element of strength for the principle of operant conditioning:
Reflexes and other innate patterns of behavior evolve because they increase the chances of survival of the species. Operants grow strong because they are followed by important consequences in the life of the individual” (Skinner, 1953, p. 93).

Skinner clearly sees that getting finalistic (or mentalistic) concepts out is where the strength of both theory lies:
Evolutionary theory moved the purpose which seemed to be displayed by the human genetic endowment from antecedent design to subsequent selection by contingencies of survival. Operant theory moved the purpose which seemed to be displayed by human action from antecedent intention or plan to subsequent selection by contingencies of reinforcement. (Skinner, 1974, p. 224, quoted in Fodor & Piattelli-Palmarini, 2010, p. 179).

The affinity between operant conditioning and natural selection is no coincidence. It is extremely plausible that operant conditioning has been selected as principle of functioning of some organism through a mechanism of natural selection (Dennett, 1978). As Skinner says “it is not difficult to show that an organism which is reinforced by the withdrawal of certain conditions should have an advantage in natural selection” (Skinner, 1953, p. 173) and likewise advantage in natural selection is given to organisms reinforced by the deliver of others certain conditions.
Thanks to this continuity with the principle of natural selection, the principle of operant conditioning is able to accommodate psychology into the Darwinian paradigm and to allow the replacement of mentalistic concepts with mechanistic formulations.
Instead of saying that a man behaves because of the consequences which are to follow his behavior, we simply say that he behaves because of the consequences which have followed similar behavior in the past. This is of course, the Law of Effect or operant conditioning” (Skinner, 1953, p. 90).

Of course it is not enough to simply say that the Law of Effect can account for every behaviour and in Verbal Behavior 
Skinner tries to explain human complex and verbal behaviour with the same principles derived from animal research (first of all the principle of operant conditioning).
As Skinner clearly states the book is an exercise of interpretation and not the experimental verification of the principles derived from animal research.
One important feature of the analysis is that [...] little use is made of specific experimental results. The basic facts to be analyzed are well known to every educated person and do not need to be substantiated statistically or experimentally [...] No effort has been made to survey the relevant "literature," The emphasis is upon an orderly arrangement of well-known facts, in accordance with a formulation of behavior derived from an experimental analysis of a more rigorous sort. The present extension to verbal behavior is thus an exercise in interpretation rather than a quantitative extrapolation of rigorous experimental results.” (Skinner, 1957)

Like we can gather from this and other passages of the book, Skinner position is that the generalizability to verbal behaviour of the basic principles is warranted by their scientific strength and by a well-established principle of uniformity, that is the assumption, invariably adopted in science, that the principles that emerge in the laboratory can be extended to domains where experimental control is impossible (Palmer, 2009).

From laboratory to 'real-life' behaviour

In Science and Human Behavior Skinner offers what he considers the barest possible statement of theprocess of operant conditioning:
we make a given consequence contingent upon a certain operant, and the behavior is then observed to increase in frequency”.(Skinner, 1953, p. 64).
This process is clearly observable through experimental procedure where the independent variables are strictly controlled and the response accurately measured. It is from experimental procedures of this sort that the principle of operant conditioning is inferred:if the occurrence of an operant is followed by presence of a reinforcing stimulus, the strength is increased (Skinner, 1938, p.21, quoted in Chomsky, 1959).

But, as Chomsky (1959) argues, because the reinforcement is defined as a consequence able to increase the strength of an operant, the principle of operant conditioning is tautological.
Practically what Chomsky's criticism shows is that reinforcers can only be postdicted from the fact of reinforcement (MacCorquodale, 1970).
The problem underlined by Chomsky is methodological more than theoretical. The process of operant conditioning is clearly observable through laboratory procedures where the experimental strictures make the response and the reinforcement clearly identifiable. Nevertheless it is unverifiable in, to use Chomsky's expression, real-life behaviours. With no control on independent variables, no knowledge of the history of reinforcement of the organism, lacking any methodological procedure to identify responses belonging to the same operant (see for example the discussion on the technical difficulty to distinguish between verbal operants in Hayes, Barnes-Holmes, & Roche, 2001) the application of the principle derived from experimental procedures can be only analogical.
Chomsky's criticism is not on the basic principles derived from laboratory procedures but on their extension on complex human behaviour. “The insights that have been achieved in the laboratories of the reinforcement theorist, though quite genuine, can be applied to complex human behavior only in the most gross and superficial way” (Chomsky, 1959).
Skinner interpretations in Verbal Behavior are built in analogy to discrimination experiments (For instance, a pigeon pecks a key under differential control of a green light, Palmer, 2009). This experimental paradigm offers a powerful interpretative analogy to analyse occurrence of verbal behaviour: “Paris” the student reply under the differential control of the question “What is the capital of France?” and we infer that the question has been encountered in school and that the appropriate response has been reinforced.
But let's consider a different kind of request unlikely to be encountered in the past (such as “Your money or your life”, see Skinner 1957, Chomsky 1959, p. 15). The correct response (handing over the wallet) is unlikely to have a history of reinforcement, still few would fail to emit the correct response.
Many similar examples may be found. Palmer (2009) offers an analysis of the features of complex human behaviour that struggle to be framed as a discriminated operant and concludes that the different examples share the feature that appropriate behaviour “seems to come out of nowhere.” (Palmer, 2009, p. 7; Dennett, 1978)
According to Graham (2010) this is the main criticism to the behavioural account of human behaviour: “It appears to be a fundamental fact about human beings that our behavior and behavioral capacities often surpass the limitations of individual reinforcement histories. Our history of reinforcement is often too impoverished to determine uniquely what we do or how we do it”.
Traditionally the behavioural reply to this critique has involved the concepts of (stimulus or response) generalization and respondent conditioning (Barnes-Holmes D., Barnes-Holmes Y., Cullinan V., 2000; see for example MacCorquodale, 1970).
Basically it is claimed that the situation and the response is similar in some essential respect to the novel situation or response and that the maintaining reiforcement has acquire his reinforcing power through a history of pairing with primary reinforcers.
It has to be claimed “that this is not truly novel behavior at all, but an instance of a general sort of behavior which has been previously conditioned […] that the stimulus I now encounter (and these are not defined) are similar in some crucial but undescribed respect to some stimuli encountered in my past which where followed by responses of some sort similar to the one I now make, where the past responses were reinforced somehow by their consequences” (Dennett, 1978).
The extention of the principle of operant conditioning to complex human behaviour is supported “by ad hoc postulation of reinforcers and stimulus histories for which one has not the slightest ground except the demand of the theory. For instance one […] presumes that when one exhibits an apparently novel bit of intelligent behavior, there must have been some “relevantly similar” responses in one's past for which one was reinforced (Dennett, 1978).

The experimental paradigm is a strong analogy to explain complex human behaviour. Its success lies on the scientific value of the principle of operant conditioning. Its explanatory power has been proved in basic research, and opened several field of application (such as education, management, psychotherapy). 'Verbal Behavior' is written with the conviction that what has been prove working with animal would work to account for complex human behaviour but its interpretations are unfalsifiable and therefore unverifiable (lacking the possibility of experimental support).
50 years of behavioural research has show that explanations of verbal behaviour may be different from those hypothesize by Skinner and may involve phenomena such as derived stimulus relations, transformation of stimulus function, private events in the role of antecedent, reinforcements and punishments (Friman, Hayes, & Wilson, 1998). Nevertheless these phenomena are analyzable according to the basic principle of operant conditioning (Hayes, Barnes-Holmes, & Roche, 2001) and so are in strict continuity with the rest of behaviourist literature (Osborne, 2003). Human behaviour is being proved to be extremely more complex than Skinner speculations, but not independent from the principles he conceived.
Barnes-Holmes D., Barnes-Holmes Y., Cullinan V., (2000). Relational Frame Theory and Skinner'sVerbal Behavior: A Possible Synthesis. The Behavior Analyst, 23, 69-84.
Chomsky, N., (1959). Review of B. F. Skinner, Verbal Behavior. Language; 35, 26–58.
Dennett, D. C., (1978). Brainstorms, Cambridge, MA: The Mit Press/ A Bradford Book.
Fodor, J. A. & Piattelli-Palmarini, M., (2010). What Darwin Got Wrong. New York: Farrar, Straus & Giroux.
Friman, P. C., Hayes, S. C., & Wilson, K. G. (1998). Why behavior analysts should study emotion: The example of anxiety. Journal of Applied Behavior Analysis, 31, 137–156.
Graham, G., (2010). "Behaviorism", The Stanford Encyclopedia of Philosophy (Fall 2010 Edition), Edward N. Zalta (ed.), URL = <>.
Hayes, S. C., Barnes-Holmes, D., & Roche, B. (Eds.). (2001). Relational Frame Theory: A Post-Skinnerian account of human language and cognition. New York: Plenum Press
MacCorquodale, K., (1970). On Chomsky's review of Skinner's Verbal Behavior. Journal of the Experimental Analysis of Behavior.;13: 83–99.
Osborne, J. G. (2003). A review of Relational Frame Theory: A Post-Skinnerian Account of Human Language and Cognition. The Analysis of Verbal Behavior, 19, 19–27.
Palmer, D., (2009). The role of private events in the interpretation of complex behavior. Behavior and Philosophy, 37, 3-19.
Skinner, B. F., (1953). Science and Human Behavior, New York: Macmillan.
Skinner B.F., (1957). Verbal behavior. New York: Appleton-Century-Crofts.

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