The Story of Psychology (70 page)

As opposed to admiration like Kagan’s, for several decades there has been a rising tide of revision and modification of Piaget’s ideas and findings; thousands of neo-, post-, and anti-Piagetian papers have been published or delivered at seminars. While much of this work has value, most of it is small stuff compared with the work of the giant himself. Isaac Newton once said, with false modesty, “If I have seen farther, it is by standing on the shoulders of giants”; the swarm of psychologists who have been correcting and revising Piaget’s theory could say in all truth that they see farther than he because they stand on his shoulders.

In the 1920s, Piaget’s early publications launched the modern study of cognitive development in Europe and America. But in the United States interest soon waned; behaviorism was becoming supreme and its adherents saw little value in what they considered new wine in the old bottle of mentalism. However, in the 1960s, when cognitivism began to regain favor, Piaget was rediscovered, and intellectual development research in his mode became a booming field.

But the tidy outlines of Piaget’s theory became blurred as swarms of doctoral candidates and psychologists, performing hundreds of Piaget-inspired studies, produced findings that often modified and sometimes challenged various aspects of the original. In the course of the past four
decades, the field of cognitive development, though still much influenced by Piaget, has become an overgrown and unweeded garden. Outside it, moreover, researchers in two relatively new and burgeoning fields, cultural psychology and evolutionary psychology, have been vigorously raising a crop of studies that broaden and modify developmental psychology in distinctly non-Piagetian ways. But we will defer looking into these two specialties until we have seen what has been happening in Piagetian-based studies, some of which are sure to enlighten, delight, and occasionally astonish the viewer. Here, with no pretense to completeness or even representativeness, is a small gathering of the flowers and fruits of several decades of this genre of research.

Memory:
How is one to investigate the memory of an infant who cannot speak, or, in the case of a newborn, indicate recognition even by facial expressions or hand movements? Researchers have thought up ingenious approaches to the problem. In an experiment conducted in 1959, infants less than a month old were conditioned to turn their heads at a particular sound (they turned them in response to a touch on the cheek and were rewarded by a bottle); a day later they still turned their heads when they heard the sound.
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The method, used with infants of different ages, yielded data on the growth of memory.

With infants a few months old, the method most frequently used has been the observation of their eye movements. The baby lies on his back looking up; above him is a display area where the experimenter puts two large cards, each containing a design such as a circle, a bull’s-eye, or a sketch of a face. The researcher times how long the baby’s eyes are directed at one pattern or the other. Since infants look at a new image longer than at a familiar one, the method yields a direct indication of what the infant remembers having seen.

Another technique, used in a 1979 experiment, called for a mobile to be suspended over the crib of an infant; subjects ranged from two to four months. When the baby kicked his legs, the researcher made the mobile move, and the infant soon learned to kick in order to see it move. Then he did not see the mobile again for a week, but when he did, he immediately started kicking. However, if two weeks went by, he did not. Again, the growth of memory was precisely measured.
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Such memory (recognition) is different from the more actively employed memory involved in a baby’s looking for an object that he has seen being hidden from view. If a baby of eight or nine months has twice retrieved a toy from under one of two similar covers, and if the
researcher then puts it under the other cover—while the baby watches—the baby, unless allowed to look for the toy within a few seconds, will look where he previously found the toy. His memory functions at a primitive level. But a few months later he no longer makes that mistake. The advance is due to maturation of certain brain circuits. Monkeys in whom a particular region of prefrontal cortex is surgically destroyed never learn to look under the correct cover.
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By five, children effortlessly remember thousands of words, but the longest number they can repeat after hearing it read slowly is four digits long. By six or seven they can remember five digits, and by nine to twelve, six. This increase, however, comes about less from maturation than from the knowledge of how to remember. Before going to school children do not “rehearse” (repeat or review) information or use associative strategies; parents of a first-grader are often puzzled that their child can’t remember what went on at school that day. But in school children gradually learn memory strategies and soon know how, for instance, to visualize themselves in class at the beginning of the school day and so recall what happened first, and next, and next.
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Sense of self, sense of competence:
The young child’s explorations of its world are a measure of his sharpening sense of self and growing sense of competence. At nine months, children still mouth and bang objects or aimlessly turn them over and over, but toward the end of their first year they begin to explore actual uses of those objects: they try drinking from a toy cup, “talking” into a toy phone, and so on. They become interested in investigating new territory and will momentarily crawl out of the mother’s sight; they turn whatever knobs and dials they can reach; they open closet and cupboard doors and take everything out. Such activities show what many developmentalists call “the attainment of competence.” Exploratory behavior, contrary to behaviorist theory, is not the consequence of rewarded acts but is spontaneous and self-initiated; the human infant and child has a need to investigate his own capacity for acting on objects, intervening in events, and widening his horizons.
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Another indication of the growth of the sense of competence is the smile of a child nearing two, even if no one is present, on successfully building a tower, putting a final piece in a puzzle, or fitting a dress on a doll. At the same time the child is becoming aware of failure and its meaning about the self. Jerome Kagan and his colleagues have noted that between fifteen and twenty-four months, children show anxiety if an adult demonstrates a form of advanced play and then tells them it is
their turn. The play may consist of making a doll cook food in a pan and then have two dolls eat dinner, or making three animals take a walk and then hide under a cloth to avoid getting wet. Faced with the challenge of following such a relatively complicated scenario, children will fuss, cry, or cling to their mother. Kagan has interpreted this as evidence of the child’s fear of being unable to remember or to carry out the play in front of the adult, since if no onlooker is present, the child will often try out the modeled act or some part of it.
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Language and thought:
Piaget believed that language plays only a limited role in the development of thought and that logical thinking is primarily nonlinguistic and derives from actions—first, doing things to the world around one, and later, doing things to one’s mental images of those things.
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Developmentalists in the Soviet Union and America found evidence to the contrary. Although it is true that some thinking is nonlinguistic, language is a set of symbols that give the child extraordinary freedom to manipulate the world mentally and to behave appropriately toward new stimuli without needing to experience them directly (“It’s hot—don’t touch”). Jerome Bruner, an eminent developmentalist, has long maintained that language is a crucial part of the child’s symbol system and “a means, not only for representing experience, but also for transforming it.”
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A bit of research evidence about the role of language in thought: Prekindergarten children were shown three black squares and told to choose one; if they chose the largest, they were rewarded. Once they had learned to choose the largest, they were shown three new squares, the smallest of which was the same size as the former largest one; again it was the largest that was rewarded. But the children had no mental symbols with which to tell themselves to “always choose the largest” and kept picking the size that had previously been rewarded, even though it now brought no reward. Kindergarten and older children, however, were quickly able to tell themselves to choose “the largest one,” regardless of the actual size of the square.
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More complex and advanced problems are also easier to solve if words are used to guide thought. A group of nine- and ten-year-olds was instructed to think out loud while trying to solve difficult problems involving moving disks from one circle to another in the fewest moves; another group did not receive these instructions. The group that thought out loud solved the problems faster and more efficiently than the silent group; the deliberate use of words caused them to think of new
reasons for trying one method or another and thus helped them find correct solutions.
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Language acquisition:
Developmentalists and psycholinguists (psychologists interested in language acquisition and use) have spent a great deal of time in recent decades listening to children speak, calculating how rapidly they learn new words, tracking the kinds of mistakes and corrections they make, and so on. Among the findings is that children develop or acquire new forms (word endings, forms of verbs, prepositions) in a relatively uniform sequence. Between two and four their vocabularies increase from a few hundred words to an average of twenty-six hundred. (They acquire fifty or more per month.) They first imitate verb forms they hear, then generalize on verb endings, reasonably (but wrongly) assuming that language has regularities throughout (“I taked a cookie,” “I seed the birdie”), and only slowly learn to use irregular verb forms. They stubbornly cling to their grammatical errors, as in this bit of dialogue reported by one psycholinguist:

They correct their errors by themselves when they are good and ready. Apparently they acquire many elements of grammar that they do not use until, at some moment, they mentally compare what they are saying to some stored knowledge and see the discrepancy.

The most significant advance in the study of language acquisition concerns the means by which children understand syntax—the arrangement of words in a sentence that denotes their relationship to one another and thus the meaning of the sentence. In 1957 B. F. Skinner published a book called
Verbal Behavior
, in which he explained the child’s acquisition of language entirely in terms of operant conditioning:
when the child uses a word or sentence correctly, the parents or others approve, and that reward conditions the child to use it correctly the next time.

But in the same year Noam Chomsky, a brilliant young psycholinguist, presented a radically different analysis in his
Syntactic Structures.
He asserted that “there must be fundamental processes at work quite independently of ‘feedback’ from the environment”; the brain must have inborn capacities to make sense of language. As evidence, he pointed out that children produce innumerable sentences they have never heard, which makes imitation through conditioning seem a quite inadequate explanation of sentence formation. Furthermore, children’s efforts to make sentences are often ungrammatical but never grossly in violation of syntax. (They never produce backward sentences.) Most important, children understand what is meant even when the form of a sentence is ambiguous; they must have a built-in ability to perceive the “deep structure” of the sentence, whatever its “surface structure.” An example Chomsky gave:

The sentences have the same surface structure, but if you try to paraphrase them in the same fashion, only one makes sense:

No child makes such an error; every child comprehends the deep structure. “John” in the first sentence is the
deep object
of “please,” so the paraphrase works; “John” in the second sentence is the
deep subject
of “please,” so that any paraphrase has to take the form “John is eager to please (someone).” An understanding of deep structure is not learned from surface structure or from rules of thumb; the ability to perceive it is innate. (Neither Chomsky nor any other psycholinguist, however, says that language itself is innate, but only that the child has an innate predisposition to recognize and interpret the deeper structure of sentences.)

In recent studies of creoles—languages that have evolved from the mixing of existing languages—the linguist Derek Bickerton has found that creoles formed in different parts of the world are more similar to each other in grammatical structure than to long-lived languages. He
also has claimed that pidgin—an informal first-generation creole that lacks consistent grammatical rules—tends to become more developed and grammatical when spoken by the children whose parents speak it. Both bodies of evidence, according to Bickerton, are evidence of the brain’s built-in sense of grammar.
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