THOUGHT

covert symbolic responses to intrinsic (arising from within) or extrinsic (arising from the environment) stimuli. Thought, or thinking, is considered to mediate between inner activity and external stimuli. In everyday language the word thinking covers several distinct psychological activities. It is sometimes a synonym for tending to believe, especially with less than full confidence. (I think that it will rain, but I am not sure.) At other times it denotes attentiveness (I did it without thinking); or it denotes whatever is in consciousness, especially if it refers to something outside the immediate environment. (It made me think of my old grandmother.) In the sense on which psychologists have concentrated, thinking is intellectual exertion aimed at finding an answer to a question or a means of achieving a desirable practical goal. The psychology of thought processes concerns itself with activities similar to those usually attributed to the inventor, the mathematician, or the chess player; but psychologists have not reached agreement on any definition or characterization of thinking. For some it is a matter of modifying cognitive structures (i.e., perceptual representations of the world or parts of the world). Others view thinking as internal problem-solving behaviour. Perhaps the most satisfactory provisional conception of thinking is one that applies the term to any sequence of covert symbolic responses (i.e., occurrences within the human organism that can serve to represent absent events). If such a sequence is aimed at the solution of a specific problem and fulfills the criteria for reasoning, it is called directed thinking. Reasoning, of which rudimentary forms can be inferred to occur in infrahuman mammals, is a process of piecing together the results of two or more distinct previous learning experiences to produce a new pattern of behaviour. Directed thinking contrasts with other symbolic sequences that have different functions; e.g., the simple recall (mnemonic thinking) of a chain of past events. In the past, psychologists and laymen often identified thinking with conscious experiences. But as the scientific study of behaviour came to be recognized generally as the task of psychology, the limitations of introspection as a source of data have become widely apparent. It thus has become more usual to treat thought processes as intervening variables or constructs with properties that must be inferred from relations between two sets of observable events. These empirically available events are inputs (stimuli, present and past) and outputs (responses, including bodily movements and speech). For many psychologists such intervening variables are of interest as aids in dealing with and in making sense of the immensely complicated network of associations between stimulus conditions and responses, the analysis of which otherwise would be prohibitively cumbersome. Others are concerned, rather, with identifying cognitive (or mental) structures that are held to underlie a human being's observable behaviour without his necessarily being aware of them. covert symbolic responses to intrinsic (arising from within) or extrinsic (arising from the environment) stimuli. Thought, or thinking, is considered to mediate between inner activity and external stimuli. Depending on the relative intensity of intrinsic and extrinsic influences, thinking can be expressive (imaginative and full of fantasy) or logical (directed and disciplined). Other terms for the two aspects of thinking are, respectively, autistic (subjective, emotional) and realistic (objective, externally directed). Both types of thinking are involved in normal adjustment. Realistic thinking. Logical, or realistic, thought includes convergent thought processes, which require the ability to assemble and organize information and direct it toward a particular goal; judgment, the discrimination between objects, items of information, or concepts; problem solving, a more complex form of realistic thinking; and creative thinking, the search for entirely new solutions to problems. Autistic thinking. Thought that is characterized by a high level of intrinsic influence and a low level of extrinsic influence includes free association, the giving of unconstrained verbal response to stimuli, found helpful in bringing repressed or forgotten experiences to consciousness; fantasy, characterized by sensory imagery in which a person loses contact with the environment, and ranging from vague reveries to vivid images; marginal states of consciousness, such as those experienced just before falling asleep or those induced by drugs; dreaming (see dream); and pathological thinking, which may be the result of antisocial behaviour disorders, neuroses (see psychoneurosis), or psychoses (see psychosis). The latter is characterized by major distortions in thinking and the lack of a realistic relation to the external environment. Theories of thought and thought processes have concentrated on directed thinking, in which thinking is organized in order to solve a problem. Theories have been concerned with both the elements of thought and with the procession of elements. According to one view, the elements organized by thinking are very weak nerve impulses sent to various muscles such that if the impulses were stronger, they would cause overt behaviour. At first it was thought that these impulses were primarily sent to the muscles used for speaking, so that thinking was seen as a kind of unexecuted speech; evidence that other muscles also receive very weak impulses during thinking led to the so-called peripheral theory, which holds that thinking goes on in the entire body by means of implicit muscular activities. In the last few decades psychologists have come to give more credence to so-called centralist theories, which hold that the locus of thinking is the brain, and that the implicit muscular activity is, in effect, a by-product. There are other conceptions of the elements of thought that regard them in more mentalistic terms. The Gestalt theorists of the 1920s and 1930s believed the elements to be of the nature of patterns elicited from experience. A more contemporary approach, influenced by the development of computers, considers the elements of thought as bits of information undergoing processing. At the beginning of this century the early behaviourists suggested that thought proceeded by association. The basic principles of association are similarity and contiguity, whereby an idea of something is followed by an idea of a similar or related thing. A later, more sophisticated view that thinking proceeds according to the whole of a situation was emphasized by the Gestalt psychologists. They argued against the turn-of-the-century view that thinking proceeds by an internal process of trial-and-error, whereby a thinker imagines various responses to a stimulus, eliminates those that are inappropriate, and thus gradually comes to a final response. By contrast, the Gestalt theorists held that the solution to a problem comes as the result of a sudden insight into the nature of the problem as a whole. Around 1950, however, evidence was found that integrated these two views, by suggesting that the thinker must become familiar with a problem through trial-and-error before being able to grasp its structure as a whole. Stimulated by advances in computer science, researchers have become concerned not simply with which thought element follows which, but also with operations that shift one element to the next. It is argued that these operations exploit a kind of controlled trial-and-error: in what is called a heuristic approach, the most promising avenues of solution to a problem are attempted first. Another topic of current interest concerns the motivations for thinking. According to the Gestalt (see Gestalt psychology) theorists, the motivation arises when a person experiences a gap in his or her overall conception of a situation. A similar view is held by neobehaviourists, who note that there are affective (emotional) rewards for resolving inconsistencies between thoughts. Additional reading R. Thomson, The Psychology of Thinking (1959), a readable summary account of experimental approaches to thinking; P.C. Wason and P.N. Johnson-Laird (eds.), Thinking and Reasoning (1968), a collection of reprinted readings by many of the leading contributors to the field; G. Humphrey, Thinking: An Introduction to its Experimental Psychology (1951), a scholarly and thorough critical review of theoretical treatments. The most influential directions in 20th-century theorizing may be found in M. Wertheimer, Productive Thinking, ed. by S.E. Asch et al. (1945), on Gestalt theory; O.H. Mowrer, Learning Theory and the Symbolic Processes (1960), on S-R or neo-associationist behaviour theory; A. Newell and H.A. Simon, Human Problem Solving (1971), on computer simulation; Jean Piaget, La Psychologie de l'intelligence (1947; Eng. trans. 1950), a compressed account of the first 20 years of this author's work; F.C. Bartlett, Thinking (1958), the treatment of thinking as a form of skill, sometimes known as the information-processing approach; and L.S. Vygotski, Thought and Language (1962; orig. pub. in Russian, 1934), the fountainhead of most Soviet research on the topic. D.E. Berlyne, Structure and Direction in Thinking (1965), reviews experimental findings, discusses crucial problems, and attempts a synthesis that draws on S-R behaviour theory, Piaget's ideas, and modern Soviet research, among other developments. See also Gilbert Ryle, On Thinking (1979), eight essays by an important theorist; and Charles Hampden-Turner, Maps of the Mind (1981), a survey of concepts of the mind held by many theorists throughout history.