The Story of Psychology (58 page)

Eventually, after reaching a number of dead ends, many subjects get around to more productive “functional” heuristics (a few others use them from the outset), such as trying to identify the essential properties of the problem. They ask themselves, for instance, what the fundamental goal is, and only then do they look for a specific solution. In the above protocol, the subject began thinking this way when he said, “One ought to decrease the intensity of the rays on their way.” He then
reverted to the first kind of thinking (“Perhaps one could alter the location of the tumor”), but after the experimenter reminded him of his more basic heuristic he suddenly had his dramatic insight into a feasible solution. The mechanical heuristics are analogous to the chicken’s running back and forth along the fence, the functional heuristics to looking at the situation in broad perspective and seeing a less direct but effective way of reaching the goal.

Duncker’s other principal research method was to bring a subject into a room where a jumbled array of objects and materials lay on a table and then ask him to perform a task for which none of the objects seemed suitable. The goal was to see under what conditions the subject would weigh other possible uses of one or more of the available objects and under what conditions such restructuring was inhibited.

In one situation, for instance, the subject was asked to mount three small candles on the door at eye level, ostensibly for “visual experiments.” On the table were some candles, a few tacks, paper clips, pieces of paper, string, pencils, and some other objects, including the crucial ones: three small empty cardboard boxes. After fumbling around, every subject eventually restructured his view of the things at hand and saw that the boxes could be tacked to the door and used as little platforms to mount the candles on.

But in another version of the problem, the three boxes were filled, one with little candles, the second with tacks, and the third with matches. This time, fewer than half of Duncker’s subjects solved the problem. They had seen the boxes being used for a specific purpose, and that made it harder to see them as usable in an unboxlike way.
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Duncker called this common and serious impediment to problem solving “functional fixedness”; when a problem solver sees an object as having a specific function, it is far more difficult for him to see it as serving any other function.

This was a noteworthy discovery. It explains why so often the very people who know most about any subject are the least likely to find a good solution to a new problem in their field. Education creates expertise but also functional fixedness. An expert sees the tools he has at hand in terms of the functions he knows they serve; a neophyte may, while coming up with uninformed and even absurd suggestions, see them more creatively. It is no accident that scientists generally make their most original and important contributions early in life.

Duncker, thought by many to have been the most brilliant of the Gestalt group in the 1930s, might have gone much farther with his
investigation of problem solving had he not died tragically early. A political liberal, he fled from Germany in 1935 and went first to England and, in 1938, to the United States to teach at Swarthmore. In 1940, at thirty-seven, deeply depressed by the outbreak of war, he committed suicide.

The studies of problem solving by Köhler, Duncker, and other Gestalt psychologists look relatively simple but their implications were profound. They demonstrated that problem solving in human beings (and to some extent in animals) is not limited to trial and error and to conditioned responses but often involves certain kinds of higher-level thinking that produce new vision, thoughts, and solutions. The studies of problem solving were one of the most important ways in which the Gestaltists restored mind as the central concern of psychology.

For many centuries the study of how knowledge is acquired had been one of the chief interests of psychologist-philosophers and psychologists. But with the advent of the physiologist-psychologists and Wundt, most of it was stored in the attic of culture with other obsolete mentalist topics.

What little the physiologists and followers of Wundt said about learning was mostly secondhand associationism; they saw it as merely the linking or joining of bits of experience. The behaviorists made learning the central topic of their research—but only the mindless learning of SR conditioning; the higher-level mental processes involved in much human learning were ignored in favor of such calculations as the relationship between the number of reinforced trials and the strength of the established habit.

Among the contributions of the Gestaltists, and perhaps their greatest, was the restoration of meaning and thought to the study of learning. Although the Gestalt movement flourished only briefly in Germany and did not replace behaviorism in the United States, it revived and renovated the cognitive tradition and prepared the way for the cognitive revolution of the 1960s.

It was not the human mind, however, but the mind of the hen that provided the first solid evidence that associationist and S-R theories of
learning were seriously inadequate. Köhler, during his stay on Tenerife, conducted a tedious but enlightening experiment with four chickens. He allowed two of them to peck at grain scattered on a light gray square of paper but shooed them away whenever they tried to peck at grain on a darker gray square of paper. He gave the other two chickens the opposite treatment. Chickens are notoriously stupid, but after four hundred to six hundred trials the first two would peck only at grain on the lighter paper and the second two only at grain on the darker paper.

Köhler then altered both situations. He kept the background color the chickens had been trained to eat from but replaced the other one, substituting a still lighter paper in the first case, a still darker one in the second. Associationist and S-R theory would predict that since the chickens had learned to associate eating with a particular shade of gray, they would continue to do so, but in 70 percent of the trials they pecked at grain on the new backgrounds rather than the old ones. The pair that had been trained to eat from the lighter of two backgrounds now mostly chose the new, still lighter background; the two who had been trained to peck at the darker of two backgrounds now mostly chose the new, still darker background. Gestalt theory offered an answer: The chickens had learned to associate food not with a specific color but with a
relationship—
in one case the lighter, in the other case the darker, of two backgrounds.
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Köhler repeated the experiment with chimpanzees and with a three-year-old child. He presented each with two boxes, one of a dull color, the other of a bright color. When a chimpanzee was the subject, the bright-colored box had a bit of food in it; when the child was the subject, a bit of candy. After the chimpanzee and the child learned that the bright box contained the reward, Köhler eliminated the dull box and substituted a new one, even brighter than the reward box. This time he put a reward in both boxes so that there was no incentive for the subjects to choose either except its color relationship to the other—and in fact the chimpanzees and the child usually chose the new, brighter box.

Behaviorists and Wundt’s followers had known that an animal can be trained to choose one of two different-colored objects, but had refused to believe that what the animal learned was the relationship between the colors. To these “elementalist” psychologists, a relationship could not be a primary psychological fact. As Solomon Asch, a student of Wertheimer’s, observed, “This premise was sufficiently potent to blot out the ceaseless evidence of experience.”
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But Köhler’s experiment showed conclusively that the relationship
between the colors was indeed the primary fact the animals had learned, since they
transposed
it to a different situation.
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It was an example of the general rule, said Asch, that animals and humans perceive and learn nearly everything in terms of relationships. This object stands on top of that one, is between two others, is bigger than, smaller than, earlier or later than another, and so on. Relations are the key to perception, learning, and memory. That truth had been excluded from psychology but was reinstated by the Gestaltists.

Wertheimer, Köhler, Koffka, and many of their students did research on learning, but much of the credit for promulgating their cognitive view of it goes to Koffka. That shy, self-doubting, homely little man with his odd, high-pitched voice was at his best when assembling facts and theory on paper; in print he could be masterful and scathing.

Koffka himself conducted no noteworthy research on learning; nearly all his experimental work was on the perception of depth, color, and motion. But because his English was excellent, the editor of the
Psychological Bulletin
, Robert M. Ogden (who had studied with Koffka at Würzburg), invited him to prepare the first account in English of Gestalt psychology. It appeared in 1922; from then on Koffka was the unofficial spokesman of the movement. Largely through his journal articles and two books, the research findings and ideas of the Gestaltists about learning became known to the profession.

In one of those books,
The Growth of the Mind
, published in German in 1921 and English in 1924, Koffka reviewed existing knowledge about mental development from a Gestaltist viewpoint. Of the many new ideas and interpretations he offered, two stand out.

The first: Instinctive behavior is not a chain of reflexive responses mechanically triggered by a stimulus; rather, it is a group or pattern of reflexes—a Gestalt imposed by the creature on its own actions—aimed at achieving a particular goal. A young chick pecks at certain things that it “knows” are edible, but the instinct is goal-oriented, driven by hunger, not a mechanical and automatic response to the sight of food.
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The chick does not peck when sated, despite the sight of food and the existence of the reflex.

The second: Against the behaviorist doctrine that all learning consists of chains of associations created by rewards, Koffka argued that much learning takes place through the processes of organization and reorganization in the mind in advance of reward; he offered as proof Köhler’s
studies of problem solving by apes and comparable data on problem solving by children. But the exact cause of those organizing processes, he admitted, was not yet known.

Fourteen years later, in
Principles of Gestalt Psychology
(1935), a heroic attempt to review all existing knowledge of psychology from a Gestaltist viewpoint, Koffka was ready to offer a theory as to the cause of the organization and reorganization in the mind. The theory, elaborated from one originally proposed by Köhler, was that “psychophysical” forces inherent in the brain—neuronal energy fields—act like the force fields elsewhere in nature that always seek the simplest or best-fitting configuration (as in, again, the bubble, or the lines of force in a magnetic field). Hence the mind’s tendency to construct and reconstruct information in the form of “good Gestalten.”
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But are those good Gestalten faithful representations of the outside world? Koffka gave a resounding affirmative to this ancient question. He offered the theory, suggested by Wertheimer and developed by Köhler, that our thoughts about the world are
isomorphic
with the world itself— they are brain events that are, in some way, similar in structure to the external things they represent. If we see two separate lights, there are two separate areas of brain excitation; if we see movement, there is a corresponding movement in the field of arousal in the brain.
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The contents of the mind are not something wholly unlike the outside world but a neural simulacrum of it.

This solved the classic problem of how thought, a different kind of phenomenon from the material world, could represent that world. Or so it seemed to Koffka and his colleagues. But in the 1950s Karl Lashley and other neurophysiologists conducted experiments designed to interrupt the supposed electrical fields of isomorphic theory. They implanted mica plates in the visual cortex of some animals and in others placed silver foil on the surface of the brain, short-circuiting the different electrical potentials that were supposed to simulate the perceived world. In neither case did the animals respond differently to visual experiences; isomorphism and force field theory was effectively scuttled.
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Yet if force field theory is viewed not as a physiological reality but as an illuminating metaphor, it has genuine value. It says that in a manner analogous to the operation of force fields, we group, categorize, and reorganize our experiences, always seeking the simplest and most meaningful constructs of the contents of our mind. As a guiding image, this comes closer than associationism, conditioning, or any earlier epistemological theory to describing how we perceive, learn, store, and utilize
information. Field theory was not the ultimate truth, but it was a better approximation of the truth than earlier theories, and the basis of better approximations yet to come.

Memory is an aspect of epistemology about which Gestalt psychology offered some particularly useful and illuminating ideas.

One was the hypothesis, presented in some detail by Koffka, that the physiological basis of memory is the formation of “traces” in the central nervous system—permanent neural changes induced by experience. It was an acute guess; decades later, neurophysiologists would begin to discover the actual cellular and molecular changes that constitute traces.

Another keen guess dealt with the psychological basis of memory. Previously laid-down memory traces, Koffka said, influence how new experiences are perceived and remembered. Unlike associationism, which said that new experiences are merely added to old ones, Koffka said that new experiences interact with traces, traces with new experience, in ways not available to the mind early in life, and that this interaction is the cause of mental development.
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His idea would be borne out by a wealth of observational data that the Swiss child psychologist Jean Piaget was even then gathering.