Cognitive Development: The Theory of Jean PiagetEdit
Cognition' refers to thinking and memory processes, and cognitive development refers to long-term changes in these processes. While cognition has been studied from several different perspectives and in the light of several theories, the one that is both the most widely known among educators and the most frankly “developmental” is the cognitive stage theory of a Swiss psychologist named Jean Piaget. Piaget created and studied an account of how children and youth gradually become able to think logically and scientifically. This section of Chapter 3 focuses exclusively on Piaget’s ideas. Other cognitive perspectives and research—the ones that are not as fully “developmental”—are discussed in later chapters, especially Chapter 8: Instructional Strategies.
Remember my brief comments in Chapter 2 about how Piaget explained learning? There, I described Piaget as a psychological constructivist: in his view, learning proceeded by the interplay of assimilation (adjusting new experiences to fit prior concepts) and accommodation (adjusting concepts to fit new experiences). The to-and-fro of these two processes leads not only to short-term learning, as I pointed out in Chapter 2, but also to long-term developmental change. The long-term developments are really the main focus of Piaget’s cognitive theory.
Because of close observation of his own three children, and later of other children and youth, Piaget proposed that cognition developed through distinct stages from birth through the end of adolescence. By stages he meant a sequence of thinking patterns with four key features: 1) they always happened in the same order, 2) no stage was ever skipped, and 3) each stage was a significant transformation of the stage before it, and 4) each later stage incorporated the earlier stages into itself. Basically this is the “staircase” model of development that I mentioned at the beginning of this chapter. Piaget proposed four major stages of cognitive development, and called them 1) sensorimotor intelligence, 2) preoperational thinking, 3) concrete operational thinking, and 4) formal operational thinking. Each stage is correlated with a particular age period of childhood or adolescence, though only rather approximately.
The Sensorimotor Stage: Birth to Age 2Edit
In Piaget’s theory, the sensorimotor stage comes first, and is defined as the time when infants “think” mainly through their senses and motor actions. As every new parent will attest, infants touch, manipulate, look, listen to, and even bite and chew objects. These actions allow them to learn about the world and are crucial to their early cognitive development.
The infant’s actions allow the child to represent (or construct simple concepts of ) objects and events. A toy animal may be just a confusing array of sensations at first, but by acting on it repeatedly, the child gradually organizes the sensations and actions into a stable concept, toy animal. The representation acquires a permanence lacking in the individual experiences of the object; because of it, the child “knows,” or at least believes, that toy animal exists even if the actual toy animal is temporarily out of sight. Piaget called this sense of stability object permanence, a belief that objects exist whether or not they are experienced currently. It is a major achievement of sensorimotor development, and marks a qualitative transformation in how older infants (24 months) think about experience compared to younger infants (6 months).
During much of infancy, of course, a child can only barely talk, so a lot of sensorimotor development happens without the support of language. It might therefore seem hard to learn what infants are thinking, but Piaget devised several simple, but clever experiments to get around their lack of language, and that suggest that infants do indeed represent objects even without being able to talk (Piaget, 1952). In one, for example, he showed that hiding an object (like a toy animal) under a blanket consistently prompts an older infant (18-24 months) to search for the object, but fails to prompt a younger infant (less than six months) to do so. (You can try this too if you happen to have access to young infant.) “Something” motivates the search by the older infant even without the benefit of much language, and presumably the “something” is a permanent concept or representation of the object.
The Preoperational Stage: Age 2 to 7Edit
In the preoperational stage, children use their new ability to represent objects in a wide variety of activities, but they do not yet do it in organized, fully logical ways. One of the most obvious examples of this phase of cognition is dramatic play, the improvised make-believe of preschool children. If you have ever had responsibility for preschool children, you have very likely witnessed dramatic play. Ashley holds a plastic banana to her ear and says, “Hello, Mom? Can you be sure to bring me my baby doll? OK!” Then she hangs up the banana and pours tea for Jeremy into an invisible cup. Jeremy, who has been watching, giggles at the sight of all of this, and exclaims, “Ringing! Oh Ashley, the phone is ringing again! You better answer it.” And so on.
In a way, children immersed in make-believe behave like the mentally insane, in that they do not think realistically. But they are not truly insane because they have not taken leave of their senses completely. At some level, Ashley and Jeremy both know that the banana is still a banana and not really a telephone; they are merely representing it as a telephone. They are thinking on two levels at once—one imaginative and the other realistic. This dual processing of experience makes dramatic play an early example of metacognition, or reflecting on and monitoring thinking itself. As I explained in Chapter 2, metacognition is a highly desirable skill for success in school, one that teachers often encourage (Bredekamp & Copple, 1997; Paley, 2005). Partly for this reason, teachers of young children (in preschool, kindergarten and even into first or second grade) often make time and space in their classrooms for dramatic play, and may even get involved in it on the sidelines in an effort to extend the play further.
The Concrete Operational Stage: Age 7 to 11Edit
As children continue in elementary school, they become able to represent ideas and events more flexibly and logically. The rules of their thinking may seem very basic by adult standards and usually operate unconsciously, but nonetheless they allow children to solve problems more systematically than before, and therefore to be successful with many academic tasks. In the concrete operational stage, for example, a child may unconsciously follow the rule that “if nothing is added or taken away, then the amount of something stays the same.” This simple principle helps in understanding certain arithmetic tasks, such as in adding or subtracting zero from a number, as well as in understanding certain classroom science experiments, such as ones involving judgments of the amounts of liquids when mixed. Piaget called this period the concrete operational stage because children mentally “operate” on concrete objects and events. They are not yet able, however, to operate (or think) systematically about representations of objects or events. Manipulating representations is a more abstract skill that does not develop until later, during adolescence.
Concrete operational thinking differs from preoperational thinking in two important ways, each of which makes children more skilled as students. One difference is reversibility, or the ability to think about the steps of a process in any order. Imagine a simple science experiment, for example, such as one to explore which of several objects sink and which ones float. Both the preoperational and concrete operational child can recall and describe the steps in this experiment, but only the concrete operational child can recall them in any order. This skill is very helpful on any number of classroom tasks involving multiple steps. In teaching new vocabulary from a story, for example, a teacher might tell students to “first make a list of words in the story that you do not know, then find and write down their definitions, and finally then get a friend to test you on your list.” These directions involve repeatedly remembering to move back and forth between a second step and a first—a task that concrete operational students—and most adults—find easy, but that preoperational children often forget to do or find confusing. If the latter children are to do this task reliably, they may need external prompts, such as having the teacher remind them periodically to go back to the story to look for more unknown words.
The other new feature of thinking during the concrete operational stage is the child’s ability to decenter, or focus on more than one feature of a problem or task at a time. There are hints of decentration in preschool children’s dramatic play, which requires being aware on two levels at once—knowing that a banana can be both a banana and a “telephone.” But the decentration of the concrete operational stage is more deliberate and conscious than preschoolers’ make-believe. Now the child can attend to two things at once quite purposely. Suppose you give students a sheet with a mixture of subtraction problems on it, and ask them to do this: “Find all of the problems that involve two-digit subtraction and involve ‘borrowing’ from the next column. Circle and solve only those problems.” Following these instructions is quite possible for a concrete operational student (as long as they have been listening to you!) because the student can attend to the two subtasks simultaneously—finding the two-digit problems and identifying which of them actually involve borrowing. (Whether the student actually knows how to “borrow,” however, or only how to identify examples of such problems, is a separate question.)
In real classroom tasks, reversibility and decentration often happen together. A well-known example of joint presence is Piaget’s experiments with conservation, the belief that an amount or quantity stays the same even if it changes apparent size or shape (Piaget, 2001; Matthews, 1998). Imagine two identical balls made of clay. Any child, whether preoperational or concrete operational, will agree that the two indeed have the same amount of clay in them. But if you now squish one of the balls into a long, thin “hot dog,” the preoperational child is likely to say that the amount of that ball has changed—either because it is longer or because it is thinner, but at any rate because it is now different. The concrete operational child will not make this mistake, thanks to new cognitive skills of reversibility and decentration: for him or her, the amount is the same because “you could squish it back into a ball again” (reversibility) and because “it may be longer, but it is also thinner” (decentration). Piaget would say the concrete operational child “has conservation of quantity.”
In a sense the classroom examples that I described above also involve reversibility and decentration jointly. As already mentioned, the vocabulary activity requires reversibility (going back and forth between identifying words and looking up their meanings); but it can also be construed as an example of decentration (keeping in mind two tasks at once—word identification and dictionary search). And as mentioned, the arithmetic activity requires decentration (looking for problems that meet two criteria and also solving them), but it can also be construed as an example of reversibility (going back and forth between subtasks, as with the vocabulary activity). Either way, the development of concrete operational skills can support students in many basic academic tasks.
The Formal Operational Stage: Age 11 and BeyondEdit
The last of the Piagetian stages resembles the concrete operational stage, except that the young person becomes able to reason not only about tangible objects and events, but also about hypothetical or abstract ones. Hence it has the name formal operational stage—the period when the individual can “operate” on “forms” or representations. With students at this level, the teacher can pose hypothetical (or contrary-to-fact) problems: “What if the George Washington had lost the American Revolutionary War?” or “What if the first white explorers had settled first in California instead of on the East Coast of North America?” To answer these questions, students must use hypothetical reasoning, meaning that they must manipulate information that varies in several ways at once, and do so entirely in their minds.
Piaget was primarily concerned with hypothetical reasoning about scientific problems, and his studies of formal operational thinking therefore often look a lot like problems that middle- or high-school teachers might pose in a science class. In one, for example, a young person is presented with a simple pendulum, to which different amounts of weight can be hung (Inhelder & Piaget, 1958). The experimenter asks, “What determines how fast the pendulum swings: the length of the string holding it, the weight attached to it, or the distance that it is pulled to the side?” The young person is not allowed to solve this problem by trial-and-error with the materials themselves, but must reason a way to the solution mentally. To do so systematically, he or she must imagine that varying each factor separately, while imagining the other factors are held constant. This kind of thinking requires facility at manipulating the relevant objects and actions mentally—precisely what formal operations are about.
As you might imagine, students with an ability to think hypothetically have an advantage in doing certain kinds of school work: by definition, they require relatively few “props” to solve problems. In this sense they can, in principle, be more self-directed than students you rely only on concrete operations—certainly a desirable quality in the opinion of most teachers. Note, though, that although formal operational thinking may be desirable, it is not sufficient for school success, and it is far from being the only way that students achieve educational success. Being capable of formal or hypothetical thinking does not insure that a student is motivated or well-behaved, for example, nor does it mean that a student also has other desirable skills or qualities, such as ability at sports, music, or art. The fourth stage in Piaget’s theory is really about a particular kind of formal thinking, the kind needed to solve scientific problems and devise scientific experiments. Since many people do not normally deal with these sorts of problems in the normal course of their lives, it should be no surprise that research finds that many people never achieve or use formal thinking fully or consistently, or that they use it only in selected areas with which they are very familiar (Case & Okomato, 1996).
Social Development: Relationships and Personal MotivesEdit
Social development refers to the long-term changes in relationships and interactions involving self, peers, and family. It includes both positive changes, such as how friendships develop, and negative changes, such as aggression or bullying. (read more...)
- Piaget, J. (1952). The origins of intelligence in children. New York: International Universities Press.
- Bredekamp, S. & Copple, C. (1997). Developmentally appropriate practice, Revised edition. Washington, D.C.: National Association for the Education of Young Children.
- Paley, V. (2005). A child's work: The importance of fantasy play. Chicago: University of Chicago Press.
- Piaget, J. (2001). The psychology of intelligence. Oxford, UK: Routledge.
- Matthews, G. (1998). The philosophy of childhood. Cambridge, MA: Harvard University Press.
- Inhelder, B. & Piaget, J. (1958). The growth of logical thinking from childhood to adolescence." New York: Basic Books.
- Case, R. & Okomato, U. (1996). The role of central conceptual structures in children's thought. Hillsdale, NJ: Erlbaum.