The Psychology Book
Page 22
Miller’s theory was backed up by earlier experiments by other psychologists. In 1954, Sidney Smith conducted experiments in memorizing a sequence of binary digits—a meaningless string of ones and zeroes to anyone unfamiliar with the binary system. Smith broke the series down into chunks, at first into pairs of digits, and then in groups of three, four, and five, and then “recoded” them by translating the binary chunks into decimal numbers: 01 became 1, 10 became 2, and so on. He found that by using this system it was possible to memorize and accurately reproduce a string of 40 digits or more, as long as the number of chunks was limited to the span of working memory.
As an aid to memorizing large amounts of information, chunking and recoding is an obvious boon, but it is more than a mnemonic trick. Miller pointed out that this form of recoding is an “extremely powerful weapon for increasing the amount of information we can deal with.” It effectively stretches the informational bottleneck.
Miller’s theory of chunking says that by building up or breaking down long streams of numbers or letters into memorable chunks, we increase the amount of information we can hold in working memory.
Binary code is a way of recoding information into ever-more tightly packed parcels (through multibase arithmetic). Miller claims our chunking process operates in a similar way.
The study of memory
Miller himself moved away from the subject of memory in his later research, but his theory prompted others to examine it in more detail. Donald Broadbent argued that the real figure for working memory is probably less than seven, and this was later confirmed in experiments by Nelson Cowan, who found it to be around four chunks, depending on the length and complexity of the chunks, and the age of the subject.
In the conclusion to his paper, Miller is dismissive of the significance of the number that originally prompted it. He concludes by saying: “Perhaps there is something deep and profound behind all these sevens… but I suspect that it is only a pernicious, Pythagorean coincidence.”
GEORGE ARMITAGE MILLER
George Armitage Miller was born in Charleston, WV. After graduating from the University of Alabama in 1941 with an MA in speech pathology, he earned a PhD at Harvard in psychology, working in Stanley Smith Stevens’ Psychoacoustic Laboratory, with Jerome Bruner and Gordon Allport. During World War II the laboratory was asked to help with military tasks such as radio jamming.
In 1951, Miller left Harvard for Massachusetts Institute of Technology (MIT), then returned to Harvard in 1955, where he worked closely with Noam Chomsky. In 1960, he cofounded the Harvard Center for Cognitive Studies. He later worked as a professor of psychology at Rockefeller University, New York, and Princeton University. In 1991, he was awarded the National Medal of Science.
Key works
1951 Language and Communication
1956 The Magical Number Seven, Plus or Minus Two
1960 Plans and the Structure of Behavior (with Eugene Galanter and Karl Pribram)
See also: Hermann Ebbinghaus • Bluma Zeigarnik • Donald Broadbent • Endel Tulving • Gordon H. Bower • Daniel Schacter • Noam Chomsky • Frederic Bartlett
IN CONTEXT
APPROACH
Cognitive therapy
BEFORE
1890s Sigmund Freud proposes an analytic approach to psychotherapy.
1940s and 1950s Fritz Perls, with Laura Perls and Paul Goodman, develops Gestalt therapy—a cognitive approach to psychotherapy.
1955 Albert Ellis introduces Rational Emotive Behavior Therapy (REBT), breaking with the tradition of analysis.
AFTER
1975 Martin Seligman defines “learned helplessness” in Helplessness: On Depression, Development, and Death.
1980s A blend of Beck’s ideas and the behavior therapies of Joseph Wolpe give rise to new cognitive behavioral therapies.
After psychology had become established as a distinct field of study, around the turn of the 20th century, two main schools, or approaches, emerged. These were experimental psychology, which was dominated by the behaviorism originating from Ivan Pavlov’s experiments, and which was enthusiastically championed in the US; and clinical psychology, which was largely based on the psychoanalytical approach of Sigmund Freud and his followers. The two had little in common. Behaviorists rejected the introspective, philosophical approach of earlier psychologists, and strove to put the subject on a more scientific, evidence-based footing. The psychoanalysts explored those very introspections, with theories, rather than proof, to support their case.
Cognitive revolution
By the mid-20th century, both approaches to psychology were being critically examined. But although behaviorism was being overtaken by cognitive psychology in experimental work, the clinical sphere was offering no alternative to the psychoanalytical model. Psychotherapy had evolved into many forms, but the basic idea of psychoanalysis and exploration of the unconscious was common to all of them. Some psychologists were beginning to question the validity of this kind of therapy, and Aaron Beck was among them.
"I concluded that psychoanalysis was a faith-based therapy."
Aaron Beck
When Beck qualified as a psychiatrist in 1953, experimental psychology was focused on the study of mental processes—it was the dawn of the “cognitive revolution.” However, the practical approach of cognitive psychologists remained much the same as that of the behaviorists. If anything, they were frequently even more rigorous in establishing evidence for their theories. Beck was no exception to this. He had trained in and practiced psychoanalysis, but grew skeptical of its effectiveness as a therapy. He could find no reliable studies of the success rates of psychoanalysis—only anecdotal evidence of case reports. In his experience, only a minority of patients showed improvement under analysis, and the general consensus among therapists was that some got better, some got worse, and some stayed about the same, in almost equal numbers.
Of particular concern was the resistance of many psychoanalysts to objective scientific examination. Compared with experimental psychology, or with medicine, psychoanalysis seemed largely faith-based, with widely different results between individual practitioners. Reputation was frequently based solely on the charisma of a particular analyst. Beck concluded that “the psychoanalytic mystique was overwhelming… It was a little bit like the evangelical movement.” Many psychoanalysts regarded criticism of their theories as a personal attack, and Beck soon discovered that any questioning of the validity of psychoanalysis was likely to be countered with universal denouncement. At one time, he was turned down for membership of the American Psychoanalytic Institute on the grounds that his “desire to conduct scientific studies signaled that he’d been improperly analysed.” Those who found fault with the idea of analysis did so, some analysts argued, because of insufficient analysis of themselves.
Beck was suspicious of both the circularity of these arguments, and the link with the therapist’s own personality. Coupled with his personal experience as a practicing psychoanalyst, this led him to examine thoroughly every aspect of therapy, looking for ways in which it could be improved. He carried out a series of experiments designed to evaluate the basis and treatment of depression, one of the most common reasons for seeking psychotherapy, and found that far from confirming the idea that this condition could be treated by examination of unconscious emotions and drives, his results pointed to a very different interpretation.
Changing perceptions
In describing their depression, Beck’s patients often expressed negative ideas about themselves, their future, and society in general, which came to them involuntarily. These “automatic tho
ughts,” as Beck called them, led him to conclude that the way the patients perceived their experiences—their cognition of them—was not just a symptom of their depression, but also the key to finding an effective therapy. This idea, which came to him in the 1960s, chimed with concurrent developments in experimental psychology, which had established the dominance of cognitive psychology by studying mental processes such as perception.
When Beck applied a cognitive model to treatment, he found that helping his patients to recognize and evaluate how realistic or distorted their perceptions were was the first step in overcoming depression. This flew in the face of conventional psychoanalysis, which sought and examined underlying drives, emotions, and repressions. Beck’s “cognitive therapy” saw this as unnecessary or even counterproductive. The patient’s perception could be taken at face value because, as he was fond of putting it, “there’s more to the surface than meets the eye.”
"By correcting erroneous beliefs, we can lower excessive reactions."
Aaron Beck
What Beck meant by this was that the immediate manifestations of depression—the negative “automatic thoughts”—provide all the information needed for therapy. If these thoughts are examined and compared with an objective, rational view of the same situation, the patient can recognize how his perception is distorted. For example, a patient who has been offered a promotion at work might express negative thoughts such as “I’ll find the new job too difficult, and fail,” a perception of the situation that leads to anxiety and unhappiness. A more rational way of looking at the promotion would be to see it as a reward, or even a challenge. It is not the situation that is causing the depression, but the patient’s perception of it. Cognitive therapy could help him to recognize how distorted it is, and find a more realistic and positive way of thinking about the situation.
A distorting mirror creates a view of the world that can seem terrifying and ugly. Similarly, depression tends to cast a negative perspective on life, making sufferers feel more hopeless.
Empirical evidence
Beck’s cognitive therapy worked. for a large number of his patients. What is more, he was able to demonstrate that it worked, as he applied scientific methods to ensure that he had empirical evidence for his findings. He designed special assessments for his patients, so that he could monitor their progress closely. The results showed that cognitive therapy was making his patients feel better, and feel better more quickly, than was the case under traditional psychoanalysis. Beck’s insistence on providing evidence for any claims he made for his therapy opened it up to objective scrutiny. Above all, he was most anxious to avoid acquiring the guru-like status of many successful psychoanalysts, and was at great pains to demonstrate that it was the therapy that was successful, and not the therapist.
Beck was not the only, or even the first, psychologist to find traditional psychoanalysis unsatisfactory, but his use of a cognitive model was innovatory. He had been influenced in his reaction against psychoanalysis by the work of Albert Ellis, who had developed Rational Emotive Behavior Therapy (REBT) in the mid-1950s, and he was no doubt aware of the work of behaviorists elsewhere in the world, including the South Africans Joseph Wolpe and Arnold A. Lazarus. Although different in approach, their therapies shared with Beck’s a thoroughly scientific methodology and a rejection of the importance of unconscious causes of mental and emotional disorders.
"Don’t trust me, test me."
Aaron Beck
Once the success of cognitive therapy had been established, it was used increasingly for treating depression, and later Beck found that it could also be helpful for other conditions, such as personality disorders and even schizophrenia. Always open to new ideas—as long as it could be shown that they were effective—Beck also incorporated elements of behavior therapy into his treatments, as did many other psychotherapists in the 1980s. This has resulted in the varied forms of cognitive behavioral therapy that are used by psychologists today.
Beck’s pioneering work marked a turning point for psychotherapy, and his influence is considerable. As well as bringing a cognitive approach into clinical psychology, Beck subjected it to scientific scrutiny, exposing the weaknesses of psychoanalysis. In the process, he introduced several methods for assessing the nature and severity of depression that are still used: the Beck Depression Inventory (BDI), the Beck Hopelessness Scale, the Beck Scale for Suicidal Ideation (BSS), and the Beck Anxiety Inventory (BAI).
How people assess the same situation varies with temperament. Beck’s cognitive therapy can help patients question their perceptions, leading to a more positive outlook.
AARON BECK
Born in Providence, Rhode Island, Aaron Temkin Beck was the son of Russian Jewish immigrants. Athletic and outgoing as a young child, he became far more studious and introspective after suffering a serious illness at the age of eight. He also acquired a fear of all things medical and, determined to overcome this, decided to train as a doctor, graduating from Yale in 1946. Beck then worked at Rhode Island Hospital, before qualifying as a psychiatrist in 1953. Disillusioned with the psychoanalytical approach to clinical psychology, he instigated cognitive therapy and later established the Beck Institute for Cognitive Therapy and Research in Philadelphia, now run by his daughter, Dr. Judith Beck.
Key works
1972 Depression: Causes and Treatment
1975 Cognitive Therapy and the Emotional Disorders
1980 Depression: Clinical, Experimental, and Theoretical
1999 Prisoners of Hate: The Cognitive Basis of Anger, Hostility, and Violence
See also: Joseph Wolpe • Sigmund Freud • Fritz Perls • Albert Ellis • Martin Seligman • Paul Salkovskis
IN CONTEXT
APPROACH
Attention theory
BEFORE
1640s René Descartes says the human body is a kind of machine with a mind, or soul.
1940s British psychologist and APU director Kenneth Craik prepares flow diagrams comparing human and artificial information processing.
AFTER
1959 George Armitage Miller’s studies suggest that short-term memory can hold a maximum of seven pieces of information.
1964 British psychologist Anne Treisman suggests that less important information is not eliminated at the filter stage but attenuated (like turning down the volume) so it can still be “shadowed” by the mind.
In Britain prior to World War II, psychology as an academic discipline lagged behind Europe and the US. Britain’s psychologists had tended to follow in the footsteps of the behaviorist and psychotherapeutic schools of thought that had evolved elsewhere. In the few university psychology departments that existed, the approach followed that of the natural sciences: the emphasis was on practical applications rather than theoretical speculations.
It was in this unpromising academic environment that Donald Broadbent, who went on to become one of the most influential of the early cognitive psychologists, found himself when he left the Royal Air Force after the war and decided to study psychology. However, the practical approach proved ideal for Broadbent, who was able to make perfect use of his wartime experience as an aeronautical engineer and pilot.
"Our mind can be conceived as a radio receiving many channels at once."
Donald Broadbent
A World War II plane incorporates a dazzling display of informational data; Broadbent was interested in discovering how pilots prioritized information and what design changes would aid this.
Practical psychology
Broadbent had enlisted in the RAF when he was 17, and h
e was sent to the US as part of his training. Here he first became aware of psychology and the kind of problems it addresses, which led him to look at some of the problems encountered by pilots in a different way. He thought these problems might have psychological causes and answers, rather than simply mechanical ones, so after leaving the RAF, he went to Cambridge University to study psychology.
"One of the two voices is selected for response without reference to its correctness, and the other is ignored."
Donald Broadbent
Broadbent’s mentor at Cambridge, Frederic Bartlett, was a kindred spirit: a thoroughgoing scientist, and England’s first professor of experimental psychology. Bartlett believed that the most important theoretical discoveries are often made while attempting to find solutions to practical problems. This idea appealed to Broadbent, and prompted him to continue working under Bartlett at the new Applied Psychology Unit (APU) after it opened in 1944. It was during his time there that Broadbent was to do his most groundbreaking work. He chose to ignore the then-dominant behaviorist approach to psychology and to concentrate on the practical problems he had come across in his time in the RAF. For example, pilots sometimes confused similar-looking controls; in some planes, the lever for pulling up the wheels was identical to the one for pulling up the flaps, and the two were situated together under the seat; this led to frequent accidents. Broadbent thought these incidents could be avoided if the capacities and limitations of the pilots were taken into consideration during the design process, rather than surfacing at the point of use.