During the past half-century, the Swiss psychologist Jean Piaget devised a model describing how humans go about making sense of their world by gathering and organizing information (Piaget, 1954, 1963, 1970a, b). Piaget’s ideas provided an explanation of the development of thinking from infancy to adulthood. According to Piaget (1954), certain ways of thinking that are quite simple for an adult are not so simple for a child. Sometimes all you need to do to teach a new concept is to give a student a few basic facts as background.
At other times, however, all the background facts in the world are useless. The student imply is not ready to learn the concept. With some students, you can discuss the general causes of civil wars and then ask why they think the American Civil War broke out in 1861. But suppose the students respond with “When is 1861? ” Obviously their concepts of time are different from your own. They may think, for example, that they will some day catch up to a sibling in age, or they may confuse the past and the future.
Four Stages of Cognitive Development Piaget hypothesized for children as they grow. Piaget’s four stages of cognitive development are called sensorimotor, pre-operational, concrete operational, and formal operational. Piaget believed that all people pass through the same four stages in exactly the same order. These stages are generally associated with specific ages, When you see ages linked to stages, these are only general guidelines, not labels for all children of a certain age.
Piaget was interested in the kinds of thinking abilities people are able to use, not in labeling. Often, people can use one level of thinking to solve one kind of problem and a different level to solve another. Piaget noted that individuals may go through long periods of transition between stages and that a person may show haracteristics of one stage in one situation but characteristics of a higher or lower stage in other situations. Therefore, knowing a student’s age is never a guarantee that you know how the child will think (Ginsburg & Opper, 1988).
Infancy: The Sensorimotor Stage. The earliest period is called the sensorimotor stage, because the child’s thinking involves seeing, hearing, moving, touching, tasting, and so on. During this period, the infant develops object permanence, the understanding that objects in the environment exist whether the baby perceives them or not. As most parents discover, before infants develop bject permanence, it is relatively easy to take something away from them. The trick is to distract them and remove the object while they are not looking; “out of sight, out of mind. The older infant who searches for the ball that has rolled out of sight is indicating an understanding that the objects still exist even though they can’t be seen.
A second major accomplishment in the sensorimotor period is the beginning of logical, goal-directed actions. Think of the familiar container toy for babies. It is usually plastic, has a lid, and contains several colorful items that can be dumped out and replaced. A 6-month-old baby is likely to become frustrated trying to get to the toys inside. An older child who has mastered the basics of the sensorimotor stage will probably be able to deal with the toy better .
Through trial and error the child will slowly build a “container toy” scheme: (1) get the lid off; (2) turn the container upside down; (3) shake if the items jam; (4) watch the items fall. (Gale Encyclopedia of Childhood & Adolescence. Gale Research, 1998. ) The Preoperational Stage. By the end of the sensorimotor stage, the child can use many action schemes. As long as these schemes remain tied to physical actions, however, hey are of no use in recalling the past, keeping track of information, or planning. For this, children need what Piaget called operations, or actions that are carried out and reversed mentally rather than physically.
The stage after sensorimotor is called preoperational, because the child has not yet mastered these mental operations According to Piaget, the first step from action to thinking is the internalization of action, performing an action mentally rather than physically. The first type of thinking that is separate from action involves making action schemes symbolic. The ability to form and use symbols-words, gestures, signs, mages, and so on is a major accomplishment of the preoperational period and moves children closer to mastering the mental operations of the next stage.
This ability to work with symbols, such as using the word “bicycle” or a picture of a bicycle to stand for a real bicycle that is not actually present, is called the semiotic function. The child’s earliest use of symbols is in pretending or miming. Children who are not yet able to talk will often use action symbols-pretending to drink from an empty cup or touching a comb to their hair, showing that they know what each object is for. This behavior also shows that their schemes are becoming more general and less tied to specific actions. The eating scheme, for example, may be used in playing house.
During the preoperational stage, we also see the rapid development of that very important symbol system, language. Between the ages of 2 and 4, most children enlarge their vocabulary from about 200 to 2,000 words. As the child moves through the preoperational stage, the developing ability to think about objects in symbolic form remains limited to thinking in one direction. It is very difficult for a child to “think backwards,” or imagine ow to reverse the steps in a task. A 5-year-old, is shown two identical glasses, both short and wide in shape.
Both have exactly the same amount of colored water in them. The experimenter asks the child if each glass has the same amount of water, and she answers, “Yes. ” The experimenter then pours the water from one of the glasses into a tall, narrow glass and asks again if each glass has the same amount of water. Now she is likely to insist that there is more water in the tall, narrow glass, because the water level is higher. The child shows a basic understanding of identity it’s the same water) but not an understanding that the amounts are identical (Ginsburg & Opper, 1988).
Piaget’s explanation for her answer is that she is focusing, or centering, attention on the dimension of height. She has difficulty considering more than one aspect of the situation at a time, or decentering. The preoperational child cannot understand that increased diameter compensates for decreased height, since this would require taking into account two dimensions at once. Children at the preoperational stage have trouble freeing themselves from their own perceptions of how the world appears.
Preoperational children, according to Piaget, are very egocentric; they tend to see the world and the experiences of others from their own viewpoint. Egocentric, as Piaget intended it, does not mean selfish; it simply means children often assume that everyone else shares their feelings, reactions, and perspectives. Very young children center on their own perceptions and on the way the situation appears to them. This is one reason it is difficult for these children to understand that your right hand is not on the same side as theirs when you are facing them.
Egocentrism is also evident in the child’s language. You may have seen young children happily talking about what they are doing even though no one is listening. This can happen when the child is alone or, even more often, in a group of children-each child talks enthusiastically, without any real interaction or conversation. Piaget called this the collective monologue. Children as young as age 4 change the way they talk to 2-year-olds by speaking in simpler sentences, and even before age 2 children show toys to adults by turning the front of the toy to face the other person.
So young children do seem quite able to take the needs and different perspectives f others into account, at least in certain situations (Gelman, 1979; Gelman & Ebeling, 1989). The Concrete-Operational Stage. Concrete operations, these are different tasks given to children to assess conservation and the approximate age ranges when most children can solve these problems. According to Piaget, a student’s ability to solve conservation problems depends on an understanding of three basic aspects of reasoning: identity, compensation, and reversibility.
The student knows that if nothing is added or taken away, the material remains the same. With an understanding of compensation, the student nows that an apparent change in one direction can be compensated for by a change in another direction. That is, if the liquid rises higher in the glass, the glass must be narrower. And with an understanding of reversibility, the student can mentally cancel out the change that has been made. Another important operation mastered at this stage is classification.
Classification depends on a student’s abilities to focus on a single characteristic of objects in a set and group the objects according to that characteristic. Given 12 objects of assorted colors and shapes, the concrete-operational student an invariably pick out the ones that are round. More advanced classification at this stage involves recognizing that one class fits into another. A city can be in a particular state or province and also in a particular country. As children apply this advanced classification to locations, they often become fascinated with “complete” addresses.
Classification is also related to reversibility. The ability to reverse a process mentally now allows the concrete-operational student to see that there is more than one way to classify a group of objects. The student understands, for example, hat buttons can be classified by color, then reclassified by size or by the number of holes. With the abilities to handle operations like conservation, classification, and seriation, the student at the concrete-operational stage has finally developed a complete and very logical system of thinking.
This system of thinking, however, is still tied to physical reality. The logic is based on concrete situations that can be organized, classified, or manipulated. So, children at this stage can imagine several different arrangements for the furniture in their rooms before they act. They do not have to solve the problem strictly hrough trial and error by actually making the arrangements. But the concrete- operational child is not yet able to reason about hypothetical, abstract problems that involve the coordination of many factors at once. Piaget, 1954, 1963, 1970a, b) This kind of coordination is part of Piaget’s next and final stage of cognitive development. AUDIO Formal Operations.
Some students remain at the concrete-operational stage throughout their school years, even throughout life. However, new experiences, usually those that take place in school, eventually present most students with problems that they cannot solve using concrete perations. What happens when a number of variables interact, as in a laboratory experiment? Then a mental system for controlling sets of variables and working through a set of possibilities is needed.
These are the abilities Piaget called formal operations. At the level of formal operations, all the earlier operations and abilities continue in force, formal thinking is reversible, internal, and organized in a system of interdependent elements. The focus of thinking shifts, from what is to what might be. Situations do not have to be experienced to be imagined. Formal operations also include inductive reasoning, or using pecific observations to identify general principles. The ability to consider abstract possibilities is critical for much of mathematics and science.
Young children cannot reason based on symbols and abstractions, but this kind of reasoning is expected in the later grades (Bjorklund, 1989). Scientific thinking of formal operations requires that students systematically generate different possibilities for a given situation. For example, if a child capable of formal operations is asked, “How many different meat/vegetable/salad meals can you make using three meats, three vegetables, and three salads? the child can systematically identify the 27 possible combinations. A concrete thinker might name just a few meals, focusing on favorite foods or using each food only once.
The underlying system of combinations is not yet available. The ability to think hypothetically, consider alternatives, identify all possible combinations, and analyze one’s own thinking has some interesting consequences for adolescents. Since they can think about worlds that do not exist, they often become interested in science fiction. Because they can reason from general principles to specific actions, they often are critical of people hose actions seem to contradict their principles. Adolescents can deduce the set of “best” possibilities and imagine ideal worlds (or ideal parents and teachers, for that matter).
This explains why many students at this age develop interests in utopias, political causes, and social issues. They want to design better worlds, and their thinking allows them to do so. Adolescents can also imagine many possible futures for themselves and may try to decide which is best. Feelings about any of these ideals may be strong. Another characteristic of this stage is adolescent egocentrism. Unlike egocentric young children, dolescents do not deny that other people may have different perceptions and beliefs; the adolescents just become very focused on their own ideas.
They analyze their own beliefs and attitudes. They reflect on others’ thinking as well but often assume that everyone else is as interested as they are in their thoughts, feelings, and behavior. This can lead to what Elkind (1981) calls the sense of an imaginary audience-the feeling that everyone is watching. So, adolescents believe that others are analyzing them: “Everyone noticed that I wore this shirt twice this week. ” “The whole class thought my answer was dumb! ” Everybody is going to love my new CD. You can see that social blunders or imperfections in appearance can be devastating if “everybody is watching. ” Luckily, this feeling of being “on stage” seems to peak in early adolescence by age 14 or 15.
Piaget has taught us that we can learn a great deal about how children think by listening carefully, by paying close attention to their ways of solving problems. If we understand children’s thinking, we will be better able to match teaching methods to children’s abilities. Piaget’s fundamental insight was that individuals construct their own understanding;learning is a onstructive process.
At every level of cognitive development, you will also want to see that students are actively engaged in the learning process. They must be able to incorporate the information you present into their own schemes. To do this, they must act on the information in some way. Schooling must give the students a chance to experience the world. This active experience, even at the earliest school levels, should not be limited to the physical manipulation of objects. It should also include mental manipulation of ideas that arise out of class projects or experiments (Ginsburg & Opper, 1988).