Chapter 12 (Cognitive Development)

Stage theories of cognitive development are so named because they describe development as consisting of a series of qualitatively different periods, called stages. Each stage consists of a different way of making sense of the world. Stage theories view children as fundamentally and qualitatively different from adults in one or more respects by virtue of their being in different developmental stages. Stage theories assume that children go through stages in a fixed or stable order, never skipping stages or going backward. Presumably, the cognitive abilities and capacities gained in one stage prepare the child to acquire the abilities and capacities of the next stage. Nonstage theories of cognitive development do not see qualitative changes at different developmental periods. Instead, these theories view development as the gradual acquisition of one or more things—for example, mental associa- tions, memory capacity, perceptual discrimination, attentional focus, knowledge, or strategies. Generally speaking, nonstage theories view children as quantita- tively but not qualitatively different from adults.

Children are active participants in learning. Infants are born with mental structures (schemes) for basic reflexes like sucking. As they apply those structures to new objects, they assimilate those objects into the scheme. They also must accommodate their schemes to fit new structures.

Sensorimotor (birth-18 months) Preoperational (18 months-7 years) Concrete operational (7-12 years) Formal operational (12 years-adult)

Another important developmental achievement in the sensorimotor period is the increasing intentionality and understanding of causality. Primary circular reactions: set off by chance, like sucking one's thumb - and directed towards the body, lead to interesting result and are continued. Secondary circular reaction (4-8 months): oriented to objects outside of one's body, like shaking a rattle, or getting a mobile to spin. Tertiary circular reactions (18 months): goal- directed behaviors, like dropping a toy over the side of the crib to see what happens. Experimenting with dropping objects from varying heights with different objects.

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Piaget (1970/1988) defined assimilation as the "integration of external elements into evolving or completed structures" (p. 7). The idea here is that mental structures are applied to new objects in the world. An infant who has a structure (Piaget called it a scheme) for sucking may at first suckle only at the mother's breast. However, when new objects are placed within easy reach of his mouth, the infant may apply that structure to the new object, say, a bent finger. We say the finger has been assimilated to the sucking scheme. Accommodation, by contrast, involves changing the structures to fit new objects. A finger has a different shape and texture from a breast and must be sucked in a slightly different way. Each time the infant sucks on a new object, she changes, even if ever so slightly, the sucking scheme. That internal change in the structure is known as accommodation. Assimilation and accommodation are always present, at least to some degree, in every act of adaptation, because it is impossible for one to exist in the absence of the other. Optimally, the two are balanced, or in equilibrium.

Acquisition of object permanence One of the important developments in the sensorimotor stage is the acquisition of the con- cept of object permanence. An adult holds a novel and interesting toy in front of a seated infant, attracting his attention. As the infant reaches for the toy, however, the adult frustrates his attempts to grab it by first moving it out of reach, then blocking the infant's view by placing a screen between the infant and the toy. The reaction of the 4-month-old infant is quite surprising: A few seconds after the toy disappears from sight, the infant looks away and shows no inclination to search for it. Piaget interpreted this reaction as follows: Having no capacity for mental represen- tation, the infant experiences objects only when they are present in the here and now. Quite liter- ally, objects out of sight are also objects out of mind. An older infant (say, around 8 months) demonstrates more, if not complete, under- standing of the idea that objects continue to exist even when they are not immediately in view. An infant at roughly this age continues to search for objects that are partly hidden. A slightly older infant (10-12 months) even searches for completely hidden objects.

Semiotic function: ability to use one thing to represent another - pretending to drink from an empty cup; cradling a doll or stuffed toy as if it were a baby; "riding" on a "pretend horse" made of a stick. Language develops -Children at this age are busy rapidly acquiring a vocabulary of words that "stand for" real objects or events in the world. In this sense, language requires symbolic thought capacities. Child's thinking is egocentric -Children at this age are busy rapidly acquiring a vocabulary of words that "stand for" real objects or events in the world. In this sense, language requires symbolic thought capacities.- experimented with egocentricity with the mountain ridge play set. Development of conservation and reversibility. Reversibility: the ability to "mentally reverse" an action. Conservation Tasks: Rows of coins and water height.- Child overwhelmed by what the two rows of checkers look like. One row does indeed look "bigger" (longer) and perhaps therefore more numerous. The child has centered on the length of the rows and ignored the density (the space between checkers) or the numerosity. Also un able to mentally reverse the transformation.

Child has developed conservation and reversibility. Thought has become "decentered." -At this point, the child can attend to much more information than before and therefore can take into account more than one aspect of a situation. Piaget described this aspect of children's thought as decentered, to draw a contrast with the centered nature of preoperational thought. Concrete-operational children also can pay attention to transformations and not just to initial and final states. Classification begins to develop during this stage. Another ability that matures during the stage of concrete operations is classification. The younger, preoperational child has a great deal of trouble consistently sorting a group of objects into categories (for example, all the round things, all the square things; or all the blue things, all the red things). The preoperational child has difficulty maintaining a consistent basis of classification. He may start out sorting wooden blocks on the basis of shape but midway through the task start sorting on the basis of color. The groups he ends up with will include blocks that vary in both shape and color. The older, concrete operational child is much more consistent and hence better able to keep track of the task. Child is still tied to reasoning with concrete examples Her thinking is limited to actual or imagined concrete things. And, when compared with an older adolescent, her thinking is less systematic

Child thinks systematically For instance, when given a number of beakers containing different liquids and asked to determine how they can be mixed together to produce a liquid of a certain color, adolescents do a number of things that younger children do not. They test one combination at a time and keep track of the results of each one. Can test hypotheses about the world Reflective abstraction develops (acquiring knowledge simply from thinking) Some debate over whether all adolescents reach this period

Reactions to Piaget Methodology limited to observations of his own three children and use of the clinical method with older children and adults -Biased? -Although his (clinical) approach allows a great deal of flexibility, it also opens the door to various threats to validity, especially the possibility that the experimenter will unconsciously and subtly provide the child with cues or leading questions. Probably underestimated children's abilities, particularly as infants Evidence for distinct stages is not strong A strict interpretation of stage theory would require, for example, that all stage-related abilities appear together, a prediction not well borne out. There is also an arguable lack of evidence for the specific cognitive structures that Piaget described as underlying the different stages (Halford, 1989). Further, a variety of empirical studies have demonstrated a great deal of competence and knowledge among young children for which Piaget's theory has difficulty accounting.

Vygotsky's theory differs from Piaget's mainly in that he sees as inseparable the child and the context in which that child functions. Thus a child's ability to understand the concept of the permanent object, or to conserve number, or to reason systematically cannot be evaluated by focusing on the child alone. Instead, Vygosky held, the environment, both physical and social, within which an activity is carried out must be taken into account.

Vygotsky introduced the concept of the "zone of proximal development" to account for the fact that children can often perform in more advanced ways with guidance or collaboration from an adult (Miller, 2002). When a more competent individual collaborates with a younger, less cognitively mature child, that child's performance is typically enhanced, even if the interaction is informal (Rogoff, 1990). Developmental psychologists in the Vygotskian tradition, therefore, are more apt to investigate children working with adults on everyday tasks.

Work with infants conducted by Renee Baillargeon traces the development of perceptual understanding of objects and events across age groups (Baillargeon & Wang, 2002). Consider the ability of infants to understand the concept of physical support; for example, one object can physically support another if (typically) the supporting object is underneath the supported object and if enough of the supported object's surface makes contact with the supporting object. -By 3 months of age, infants show surprise at impossible events. i.e. the lack of support holding up the box. Our results indicate that by 3 months of age, if not before, infants expect the box to fall if it loses all contact with the platform and to remain stable otherwise. At this stage, any contact between the box and the platform is deemed sufficient to ensure the box's stability. At least two developments take place between 3 and 6.5 months of age. First, infants become aware that the locus of contact between the box and the platform must be taken into account when judging the box's stability. Infants initially assume that the box will remain stable if placed either on the top or against the side of the platform. By 4.5 to 5.5 months of age, however, infants come to distinguish between the two types of contact and recognize that only the former ensures support. The second development is that infants begin to appreciate that the amount of contact between the box and the platform affects the box's stability. Initially, infants believe that the box will be stable even if only a small portion (for example, the left 15%) of its bottom surface rests on the platform [see Figure 14-3]. By 6.5 months of age, however, infants expect the box to fall unless a significant portion of its bottom surface lies on the platform. (Baillargeon, 1994, pp. 133-134).

Children do not learn syntax (Chomsky, 1959). That is, the way in which syntax develops from infancy through adolescence is difficult to account for in terms of simple learning mechanisms. One reason is that syntactic development typically occurs in a very short time frame—in only a few years. Further, children undergoing language development hear many different utterances of a language—from parents, siblings, teachers, and others. However, what children appear to acquire are not specific sentences or utterances but rather the underlying rules that govern a particular language. As I hope Chapter 10 convinced you, the rules that govern a language are complex and very difficult to articulate. Thus it is quite unlikely that parents and other adults are teaching these syntactic rules. Rather than learning language, Children acquire language. We are born with language universals, which enables us to acquire language

Adele Diamond (1991) has extended this line of work, using a classic object permanence task in which an infant, having previously seen an object hidden in location A, watches it hidden in location B, but continues to look for the hidden object in location A instead of B. Diamond compared older (7-12 months) infants' ability on the "A, not B" object permanence task to the development of the frontal cortex. This area of the brain has been shown to undergo tremendous growth, both in density of synapses and in myelination of axons. Diamond's work has shown that improved performance on the "A, not B" task correlates with age (and therefore with frontal-lobe development) in infancy. In her work with monkeys with frontal-lobe lesions, she has produced monkeys with specific neurological deficits who show the same pattern of behavior on the "A, not B" task as do infants of different ages. More recent work involving brain imaging techniques paints the following picture: With development, the brain becomes more fine-tuned and organized. Brain regions associated with so-called "basic" functions, such as sensation and motor behavior, develop first, in line with Piagetian tenets. Association areas— brain regions that facilitate integration of information—develop a little more slowly. Areas involved in top-down control of behavior, such as the frontal and prefrontal cortex, are the last to develop (Casey, Tottenham, Listen, & Durston, 2005). Moreover, as the individual develops and has certain experiences, certain synaptic connections between neurons in the brain are strengthened, while other, unused ones, are pruned. This pruning results in more efficient neural circuits, but ones that become increasingly specialized and unique to the individual. Kuhn (2006) speculates that this brain reorganization might account for why, during adolescence, individual differences in performance become more and more common. Although it's possible to talk about the cognitive abilities of a typical 6-month-old, by the time children reach adolescence, there are much wider variations in performance—some adolescents can perform like adults on some tasks, while others cannot. One important factor in this variation, Kuhn believes, stems from the experiences the adolescents engage in, which in turn direct the maintenance or pruning of different neural circuits. ! Development of object permanence coincides with peak development of prefrontal cortex.

Working memory capacity increases with memory. Memory span, that is, the number of objects, like numbers, a child can remember increased with age. (digit span, word span, letter span) Some argue that it is not capacity that increases but speed and/or efficiency with which information is processed. -children at different ages vary in the speeds at which they can rotate mental images, search through visual displays, and name items presented to them. adults perform the fasted, presumably do to greater working memory capabilities. The younger the processor, the more mental effort is required for a given task.

Preschoolers, in particular, often respond to complex cognitive tasks impulsively—that is, quickly and with many errors (Kogan, 1983). Perhaps related to this, younger children make fewer discriminations between similar objects than do older children (Gibson & Spelke, 1983). evidenced by child's tendency to overlook similarities between pictures in cognitive tasks. In part, this has to do with the amount of time they spend looking back and forth between the two pictures. Another part of the explanation, predicted by perceptual learning theory (Gibson, 1969), seems to be that younger children notice fewer differences in the first place.

Chi and Koeske (1983) carried out a related study with a single 41⁄2-year-old fancier of dinosaurs. The investigators first queried the child about his familiarity with and knowledge about different kinds of dinosaurs and then drew up two lists: 20 dinosaurs that the child knew relatively more about and 20 that the child knew relatively less about. On three different occasions, the child was presented with each list, at the rate of 1 dinosaur name every 3 seconds, and was then asked to recall the list. The child recalled significantly more of the "familiar" dinosaurs (about 9 out of 20) than the "unfamiliar" ones (about 4 out of 20). Chi and Koeske (1983) argued from these and other results that part of the reason why children typically perform so poorly on memory (and presumably other cognitive) tasks may be their relative lack of knowledge or expertise regarding the information used in the tasks. Given the opportunity to perform the same tasks with materials they know well, their performance improves dramatically. Presumably, familiar materials require less cognitive effort to encode, retrieve relevant information about, notice novel features of, and so on.

Kemler (1983) has extended this idea, arguing that with development, children shift from a holistic approach to processing information to a more analytic one. By these terms Kemler means that younger children approach information globally and pay attention to the overall similarities between and among objects. For example, given a red triangle, an orange diamond, and a green triangle and asked to "put together the items that belong together," younger children tend to sort the red triangle and orange diamond together, because overall, these two objects are more similar to each other than either is to the green triangle. In contrast, older children and adults pay attention to particular parts or aspects of information. Given the same sorting task, adults would be likely to classify the red and the green triangles together, because they both share the dimension of shape. Children have also been shown to have difficulty focusing their attention. analytic processing: A mode of processing information in which attention is paid to specific di- mensions, features, or parts of the stimuli rather than to the overall or global aspects. holistic processing of information: Attending to global aspects of a situation in processing information about it.

metacognition, defined broadly as "any knowledge or cognitive activity that takes as its object, or regu- lates, any aspect of any cognitive enterprise" -It includes metacognitive knowledge—that is, knowledge about one's own cognitive abilities and limitations. Older children were better able to judge when they had studied adequately and to predict how many items they would be able to recall. Metacognition also includes metacognitive experiences, things that happen to you that pertain to your knowledge or understanding of your own cognitive processes. For example, experiences of uncertainty or doubt and periods of deep reflection over your performance, decision making, or values are all examples of metacognitive experiences. Flavell's (1985) idea is that older children and adults are better able to recognize, and realize the significance of, different metacog- nitive experiences. Part of the reason why younger children perform more poorly on cognitive tasks may be that they do not have the metacognitive knowledge about what the tasks demand. That is, they do not know how to judge the dif- ficulty of the task and thus do not approach it with the necessary procedures or other tools. It may also be that younger children have less metacognitive con- trol over their processing of information