The Story of Psychology (54 page)
Read The Story of Psychology Online
Authors: Morton Hunt
With the advent of the paradigm shift, behaviorism rapidly lost its commanding position in psychology and its claim to be a sufficient explanation of all behavior. Gregory Kimble of Duke University sums up the disenchantment of psychologists with behaviorism:
Although the classical theories were formulated and tested in terms of simple learning, behind the scenes there was always the presumption that these theories could be applied to all behavior… [and] that most of the basic laws of learning had already been discovered and all that remained was the minor problem of resolving the few systematic issues that separated the main theorists… [But] by the middle of the century it had become clear that the classic theories of learning were limited in scope and that the stature of our scientific knowledge was pre-Galilean rather than post-Newtonian, as Hull and others had thought.
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Curiously, it was only when behaviorism was in its decline that its off-shoot, behavior therapy, became a widely used and reasonably successful form of treatment for a limited range of psychological disorders.
What is true of behavior therapy—its usefulness but limited applicability—is similar to what has proved true of its parent, behaviorism. A number of its findings have been put to practical use, an example being taste-aversion learning: To inhibit coyotes from killing sheep, researchers put toxic lamb burgers, wrapped in sheep fur, on the perimeters of fenced areas of sheep ranches; coyotes that eat this bait get sick, vomit, and develop an instant aversion to lamb meat and to sheep.
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Other conditioning mechanisms have been used to counter the
aversion cancer patients develop to food if mealtime comes just before painful chemotherapy (the simple answer: separate mealtime widely from treatment).
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Behavior modification methods have been used in programs with mentally retarded children and adults, psychiatric patients, and prisoners: They earn “tokens” for good behavior that can be traded for privileges. Secondary reinforcement methods have proved useful in the workplace in such applications as giving employees bonus vouchers for getting to work on time.
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Phobias of various kinds, including extreme fear of snakes, have been successfully treated by step-by-step conditioning of the phobic person to thoughts of, the sight of, and eventually the handling of, snakes.
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More generally, behaviorism yielded a legacy often taken for granted but considered essential in most areas of psychology: the need for rigorous experimentation and carefully defined variables. Behavior analysis continues to attract some psychologists as a field of research and application; in addition to the 4,500 members of the Association for Behavior Analysis, another 5,000 or more psychologists are members of local chapters of ABA. But their interest in it is apparently more as an adjunct to other areas of research than a primary identification, an indication being the membership of Division 25 of APA, which peaked at some 1,600 members in the early 1970s, then slid steeply downhill to a little over 600 in the last half dozen years, about 7 percent of APA membership.
In any case, the kinds of studies being performed within the field of behavior analysis these days seem strangulated to cognitivists. Here, for instance, are the titles of typical articles in the January 2006 issue of the
Journal of the Experimental Analysis of Behavior:
“The influence of prior choices on current choice.”
“Resistance to extinction following variable-interval reinforcement: Reinforcer rate and amount.”
“Second-order schedules of token reinforcement with pigeons: Implications for unit price.”
And here is a brief excerpt exemplifying much of the work being done by contemporary behaviorists:
Rats obtained food-pellet reinforcers by nose poking a lighted key. Experiment 1 examined resistance to extinction following single-schedule training with different variable-interval schedules, ranging
from a mean interval of 16 min to 0.25 min. That is, for each schedule, the rats received 24 consecutive daily baseline sessions and then a session of extinction (i.e., no reinforcers). Resistance to extinction (decline in response rate relative to baseline) was negatively related to the rate of reinforcers obtained during baseline, a relation analogous to the partial-reinforcement-extinction effect. A positive relation between these variables emerged, however, when the unit of extinction was taken as the mean interreinforcer interval that had been in effect during training (i.e., as an omitted reinforcer during extinction)…
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It is time for us to move on to something more easily recognizable as psychology.
*
William of Ockham, a fourteenth-century Franciscan, is supposed to have said, “Entities are not to be multiplied without necessity,” although some sources claim that what he actually said was “It is vain to do with more what can be done with fewer.” In either case, the message is that the best explanation is the simplest one.
*
Observers (of their own conscious processes).
The
Gestaltists
A Visual Illusion Gives Rise to a New Psychology
O
n a train speeding through central Germany late in the summer of 1910, a young psychologist named Max Wertheimer stared at the landscape, intrigued by an illusion millions have taken for granted but that he felt, at that moment, required an explanation. Distant telegraph poles, houses, and hilltops, though stationary, seemed to be speeding along with the train. Why?
1
The puzzle led him to think about another illusory motion—that produced by the stroboscope, a toy employing the same principle as motion pictures, which were just becoming popular. In both cases, the rapid exposure to the eye of a series of photographs taken at split-second intervals, or drawings showing the smallest of changes, created the impression of continuous motion.
The phenomenon, known for decades, had never been satisfactorily explained. Thomas Edison and others who had developed motion pictures in the 1890s were content to achieve the effect without understanding what caused it. But on the train that day Wertheimer had a sudden intuition about the answer. He had taken his doctorate at Würzburg, where, in defiance of Wundtian principles, a handful of psychologists had been using introspection to explore conscious thinking. It now occurred to him that the illusion of motion might be due to something happening not in the retina, as many psychologists thought,
but in the mind, where some higher-level mental process supplied transitions between the successive pictures, thereby creating the perception of movement. He promptly lost interest in the problem of the moving landscape and never returned to it.
At the time, Wertheimer, who had been doing research at the University of Vienna on the inability to read, was on his way to the Rhineland for a vacation. But his idea so excited him that he got off the train at Frankfurt to consult Professor Friedrich Schumann, an expert on perception with whom he had studied at the University of Berlin before going to Würzburg, and who had recently moved to the University of Frankfurt.
In town, Wertheimer bought a stroboscope at a toy store and spent the evening working with it in his hotel room. (A stroboscope is a scientific instrument for seeing moving parts, as in machinery, slowed down or stationary, but in the nineteenth century and early in the twentieth the term referred to a popular toy that created the impression of motion.) The stroboscope came with pictures of a horse and boy; at the right speed of operation the horse appeared to trot and the boy to walk. Wertheimer replaced the pictures with pieces of paper on which he alternately drew lines in two locations, parallel to each other. He found that at one speed of operation he saw first one line and then the other in their different places; at another, both lines side by side; and at yet another, a single line
moving
from one position to another. He had a historic experiment and a theory of psychology in the making.
The next day Wertheimer called on Schumann at the university, told him what he had observed and what he guessed was the explanation, and asked his opinion. Schumann could cast no light on the matter but offered Wertheimer the use of his laboratory and equipment, including a new tachistoscope of his own design. With it a researcher, by regulating the speed of rotation of a wheel with slits in it, could expose a visual stimulus to the viewer for brief durations, and by using wheels with differently located slits and a prism could present the viewer with alternating images. The tachistoscope did with precision and control what the stroboscope did crudely.
Because Wertheimer would need volunteers to serve as experimental subjects, Schumann introduced him to one of his two assistants, Wolfgang Köhler, who shortly brought in the other assistant, Kurt Koffka.
2
They were somewhat younger than Wertheimer (he was thirty, Köhler twenty-two, and Koffka twenty-four), but all three were interested in the
higher-level mental phenomena that the New Psychology of the physiologists and the followers of Wundt ignored, and they hit it off at once. They were to be friends and co-workers for their entire lives.
Wertheimer, single and possessed of an independent income—his father had been director of a successful commercial school in Prague— could do as he pleased; what he pleased was to abandon his vacation plans and remain in Frankfurt for nearly half a year conducting a series of experiments, with Köhler, Koffka, and Koffka’s wife serving as his subjects.
In his basic experiment, adapted from the hotel room try-out, Wertheimer alternately projected a three-centimeter horizontal line and another one about two centimeters below it. At a low rate of exposure, his volunteers (who did not know until much later what he was doing) all saw first one line and then the other; at a high rate of exposure, both lines simultaneously; and at intermediate rates, a single line smoothly moving from the upper to the lower position and back again.
3
In a variation, Wertheimer used a vertical line and a horizontal line. At the right speed his subjects saw one line rotating back and forth through 90 degrees. In another variation he used lights; these, at the critical speed, appeared to be a single light moving. In still others he used multiple lines, different colors, and different shapes, and in every case was able to produce the illusion of motion. Even after he told his three subjects what was happening, they could not make themselves
not
see the motion. Through still other variations, Wertheimer ruled out any possibility that the phenomenon was due to eye movements or retinal afterimages.
The illusion, he concluded, was a “psychic state of affairs,” which he called the φ phenomenon. The letter
phi
, he said, “designates something that exists outside the perceptions of
a
and
b
,” resulting from a “psychological short-circuit” in the brain.
4
The φ phenomenon, he suggested, resulted from “a psychological short-circuit” in the brain between the two areas stimulated by the nerve impulses coming from the retinal areas stimulated by
a
and
b.
This physiological hypothesis did not stand up in later research; what did was Wertheimer’s theory that the illusion of motion takes place not at the level of sensation, in the retina, but of perception, in the mind, where incoming discrete sensations are seen as an organized unity with a meaning of its own. Wertheimer called such an overall perception a
Gestalt
, a German word that means form, shape, or configuration but that he used to mean a set of sensations perceived as a meaningful whole.
Seemingly, he had spent months of work to explain a trivial illusion. In actuality, he and his co-workers had sown the seed of the Gestalt school of psychology, a movement that would enrich and broaden psychology both in Germany and the United States.
*
Wertheimer’s theory that the mind adds structure and meaning to incoming sensations was distinctly out of step with the antimentalist psychology that had been dominant in Germany for nearly half a century and in America for a generation.
His theory was also out of step with the
Zeitgeist
of 1910, which centered on the transformation of life and thought by the physical sciences and technology. The electric light was radically altering nighttime in cities and even remote towns, the automobile was changing the habits of nations, airplanes were becoming capable of sustained flight (Louis Blériot had flown across the English Channel), Marie Curie had just isolated radium and polonium, Rutherford was working out his theory of atomic structure, Zeppelin passenger service had recently begun, and Lee De Forest had lately patented the radio tube. The New Psychology was in harmony with such developments; mentalist psychology seemed more than ever metaphysical, unscientific, and passé.
But for some years a number of psychologists had considered Wundtian psychology barren and confining because it did not deal with complex forms of experience such as emotions, thinking, learning, and creativity—the most important aspects of human life. James, Galton, Binet, Freud, and the members of the Würzburg School, though they had dissimilar concerns, were all interested in and had been investigating phenomena that could be explained only in terms of higher mental processes.
In addition, other researchers had been turning up bits of evidence that perceptions are not identical with the sensations received by the retina or other sense organs but are the mind’s interpretation of the data in those sensations.
As far back as 1890, Christian von Ehrenfels, an Austrian psychologist,
pointed out that when a melody is transposed, every note is changed, yet we hear the very same melody. He explained that we recognize the sameness of relations among the parts of the whole—what he called the melody’s
Gestaltqualität
or “form quality,” a crucial characteristic perceived by the mind, rather than the ears.
