One of the most popular theories of cognitive development was created by Jean Piaget, a Swiss psychologist who believed that cognitive growth occurred in stages. Piaget studied children through to their teens in an effort to determine how they developed logical thinking. He attempted to document the stages of cognitive development by observing the memory processes of children. To understand the nature of this development, Piaget carefully observed the behaviour of his own three kids. He used to present problems to them, observe responses slightly after the situations and again observe their responses. Piaget called this method of exploring development clinical interview.

Piaget was 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, but also to long-term developmental change. The long-term developments are really the main focus of Piaget’s cognitive theory.

After observing children closely, 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 happen in the same order.

2.     No stage is ever skipped.

3.     Each stage is a significant transformation of the stage before it.

4.     Each later stage incorporated the earlier stages into itself.

Basically this is the “staircase” model of development 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 an age period of childhood, but only approximately.

Piaget's Stages of Cognitive Development - Piaget's theory of cognitive  developme… | Child development theories, Cognitive development, Child  development psychology


There Are Three Basic Components to Piaget's Cognitive Theory:


Piaget called the schema the basic building block of intelligent behavior – a way of organizing knowledge. Indeed, it is useful to think of schemas as “units” of knowledge, each relating to one aspect of the world, including objects, actions and abstract (i.e. theoretical) concepts. When a child's existing schemas are capable of explaining what it can perceive around it, it is said to be in a state of equilibrium, i.e. a state of cognitive (i.e. mental) balance. Piaget emphasized the importance of schemas in cognitive development, and described how they were developed or acquired.

A schema can be defined as a set of linked mental representations of the world, which we use both to understand and to respond to situations. The assumption is that we store these mental representations and apply them when needed. For example, a person might have a schema about buying a meal in a restaurant. The schema is a stored form of the pattern of behavior which includes looking at a menu, ordering food, eating it and paying the bill. This is an example of a type of schema called a 'script'. Whenever they are in a restaurant, they retrieve this schema from memory and apply it to the situation. The schemas Piaget described tend to be simpler than this - especially those used by infants. He described how - as a child gets older - his or her schemas become more numerous and elaborate.

Piaget believed that newborn babies have some innate schemas - even before they have had much opportunity to experience the world. These neonatal schemas are the cognitive structures underlying innate reflexes. These reflexes are genetically programmed into us. For example babies have a sucking reflex, which is triggered by something touching the baby's lips. A baby will suck a nipple, a comforter (dummy), or a person's finger. Piaget therefore assumed that the baby has a 'sucking schema'. Similarly the grasping reflex which is elicited when something touches the palm of a baby's hand, or the rooting reflex, in which a baby will turn its head towards something which touches its cheek, were assumed to result operations: for example shaking a rattle would be the combination of two schemas, grasping and shaking.

Assimilation and Accommodation

Jean Piaget viewed intellectual growth as a process of adaptation (adjustment) to the world. This happens through:

Assimilation: Which is using an existing schema to deal with a new object or situation.

Accommodation: This happens when the existing schema (knowledge) does not work, and needs to be changed to deal with a new object or situation.

Equilibration: This is the force, which moves development along. Piaget believed that cognitive development did not progress at a steady rate, but rather in leaps and bounds. Equilibrium is occurs when a child's schemas can deal with most new information through assimilation. However, an unpleasant state of disequilibrium occurs when new information cannot be fitted into existing schemas (assimilation). Equilibration is the force which drives the learning process as we do not like to be frustrated and will seek to restore balance by mastering the new challenge (accommodation). Once the new information is acquired the process of assimilation with the new schema will continue until the next time we need to make an adjustment to it.

The sensorimotor stage: birth to age 2

In Piaget’s theory, the sensorimotor stage is first, and is defined as the period when infants “think” by means of their senses and motor actions. As every new parent will attest, infants continually touch, manipulate, look, listen to, and even bite and chew objects. According to Piaget, 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 looking, feeling, and manipulating it repeatedly, the child gradually organizes her sensations and actions into a stable concept, toy animal. The representation acquires a permanence lacking in the individual experiences of the object, which are constantly changing. Because the representation is stable, 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 actually present. 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 sensorimotor development initially happens without the support of language. It might therefore seem hard to know 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 simply hid an object (like a toy animal) under a blanket. He found that doing so consistently prompts older infants (18–24 months) to search for the object, but fails to prompt younger infants (less than six months) to do so. (You can try this experiment yourself 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 the “something” is presumed to be a permanent concept or representation of the object.

Substage One: Basic Reflexes (Birth – 1 month)

Children enter the world equipped with a set of inherited action patterns and reflexes through which they experience their environment. The intellectual development of the child begins through these actions as this is how the child acquires knowledge about its surroundings; this knowledge forms the basis for more complex developments further down the track. Infants are restricted in what they can know as their behaviours and schemata are limited. Adaption to their surroundings through assimilation and accommodation begins in this stage.

Substage Two: Primary Circular Reactions (1 – 4 months)

In the second substage of Piaget’s theory, the knowledge and intelligence of the infant now extends beyond the innate behaviours they were born with but these new acquistions have only come about through the accommodation of schemata. The infants show one of the first signs learning which is modifying their reflexes as a result of their environment (Bjorklund, 1995). These acquistions come about by a circular means. Actions that are at first random and activate a reflex are attempted again to try and induce the experience again. The signs of intentionality have appeared. These patterns of learning have been labelled primary circular reactions.

This is also the substage in which object permanence begins to develop and the active search for a hidden object begins.

Substage Three: Secondary Circular Reactions (4 – 8 months)

Secondary circular reactions are the first acquired adaptions of behaviours that are not reflexive, as opposed to the primary circular reactions which are reflex based. An infant in this stage may accidentally cause something interesting to happen and then seek to re-create the happy event. The interesting events in this case are located in the external wolrd, in primary circular reactions the interesting events are occuring within the body. A child in this substage, however, does still not understand the aspects of cause and effect and so will sift through the many behaviours it was indulging in when the event occurred and narrow it down to the particular action without really understanding the underlying concepts of why the event recurs.

Substage Four: Coordination of Secondary Circular Reactions (8 – 12 months)

The actions of the previous stage flourish in this stage and continue to develop, the difference is that the need now precedes the act. Intentionality occurs in interactions with the environment and the infant is moving towards goal directed behaviour. An understanding of cause and effect relationships has come into being in the childs world.

Substage Five: Tertiary Circular Reactions (12 – 18 months)

As with stage four, this stage is characterised by a means/ends differentiation. The infants are no longer restricted to the application of previously established schemata to obtain a goal. They can make the necessary alterations to their schemata to solve problems; this reflects a process of active experimentation (Bjorklund, 1995). These differences in cognition coincide with improved locomotive abilities; the children have become more physically active. In this stage, causal inferences are still unavailable to the infant; it must see an action occur before it has any understanding of the causal relationship.

Substage Six: Invention of new Means through Mental Combinations (18 – 24 months)

The earlier stages of the sensorimotor period appear to be set on a continuum but the transition from the fifth to the sixth stage is more of a disjointed transition. Symbolic function and mental representation first appear during this stage, this runs parrallel with the development of language. Language is an expression of symbolic function and mental representation and it is at this stage that the children begin to string words together in pairs, the origins of sentences.

The preoperational stage: age 2 to 7

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 ways that are organized or fully logical. One of the most obvious examples of this kind of cognition is dramatic play, the improvised make-believe of preschool children. If you have ever had responsibility for children of this age, you have likely witnessed such 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 giggles at the sight of all of this and exclaims: “Rinnng! Oh Ashley, the phone is ringing again! You better answer it.” And on it goes.

In a way, children immersed in make-believe seem “mentally insane,” in that they do not think realistically. But they are not truly insane because they have not really taken leave of their senses. At some level, Ashley and Jeremy always 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 of thinking itself. 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 (preschool, kindergarten, and even first or second grade) often make time and space in their classrooms for dramatic play, and sometimes even participate in it themselves to help develop the play further.

The preoperational period is divided into two stages:

The Symbolic Function Substage occurs between 2 and 4 years of age and is characterized by the child being able to mentally represent an object that is not present and a dependence on perception in problem solving. 

The Intuitive Thought Substage, lasting from 4 to 7 years, is marked by greater dependence on intuitive thinking rather than just perception (Thomas, 1979). At this stage, children ask many questions as they attempt to understand the world around them using immature reasoning. Let’s examine some of Piaget’s assertions about children’s cognitive abilities at this age.

Following are the accomplishments of Pre-Operational Stage:

a. Semantic function. During this stage the child develops the ability to think using symbols and signs. Symbols represent something or someone else; for example, a doll may symbolize a baby, child or an adult.

b. Egocentrism. This stage is characterized by egocentrism. Children believe that their way of thinking is the only way to think.

c. Decentering. A pre-operational child has difficulty in seeing more than one dimension or aspects of situation. It is called decentering.

d. Animism. Children tend to refer to inanimate objects as if they have life-like qualities and are capable of actions.

e. Seriation. They lack the ability of classification or grouping objects into categories.

f. Conservation. It refers to the understanding that certain properties of an object remain the same despite a change in their appearance.

The concrete operational stage: age 7 to 11

As children continue into elementary school, they become able to represent ideas and events more flexibly and logically. Their rules of thinking still seem very basic by adult standards and usually operate unconsciously, but 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: “If nothing is added or taken away, then the amount of something stays the same.” This simple principle helps children to understand certain arithmetic tasks, such as in adding or subtracting zero from a number, as well as to do 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 develops later, during adolescence.

Concrete operational thinking differs from preoperational thinking in two ways, each of which renders 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 that explores why objects sink or float by having a child place an assortment of objects in a basin of water. 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 task involving multiple steps—a common feature of tasks in the classroom. In teaching new vocabulary from a story, for another example, a teacher might tell students: “First make a list of words in the story that you do not know, then find and write down their definitions, and finally 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 younger 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 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 an assortment of subtraction problems on it, and ask them to do this: “Find all of the problems that involve two-digit subtraction and that 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!) because the student can attend to the two subtasks simultaneously—finding the two-digit problems and identifying which actually involve borrowing. (Whether the student actually knows how to “borrow” however, 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 simply because they look the same. But if you now squish one ball 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 now looks 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.”

The classroom examples described above also involve reversibility and decentration. As already mentioned, the vocabulary activity described earlier 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 support students in doing many basic academic tasks; in a sense they make ordinary schoolwork possible

The formal operational stage: age 11 and beyond

In the last of the Piagetian stages, the child 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 world had never discovered oil?” or “What if the first European explorers had settled first in California instead of on the East Coast of the United States?” To answer such questions, students must use hypothetical reasoning, meaning that they must manipulate ideas that vary in several ways at once, and do so entirely in their minds

The hypothetical reasoning that concerned Piaget primarily involved scientific problems. His studies of formal operational thinking therefore often look like problems that middle or high school teachers pose in science classes. In one problem, 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 varying each factor separately, while also imagining the other factors that are held constant. This kind of thinking requires facility at manipulating mental representations of the relevant objects and actions—precisely the skill that defines formal operations.

As you might suspect, students with an ability to think hypothetically have an advantage in many 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 who rely only on concrete operations—certainly a desirable quality in the opinion of most teachers. Note, though, that formal operational thinking is desirable but not sufficient for school success, and that it is far from being the only way that students achieve educational success. Formal thinking skills do not insure that a student is motivated or well-behaved, for example, nor does it guarantee other desirable skills, 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 such 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). For teachers, the limitations of Piaget’s ideas suggest a need for additional theories about development—ones that focus more directly on the social and interpersonal issues of childhood and adolescence. The next sections describe some of these.

Implications of Jean Piaget’s Theory for the Education of Children

1.     All development is hierarchical, that is, we must all go through the same stages in the same sequence, moving from the simple to the complex.


2.     Early learning is slower than later learning, although the rate at which we progress through a given stage is a function of an interaction between our environment and our genetic endowment. By genetic endowment. Piaget means a healthy organism and not of specific genetic programming, as is the mode today.


3.     Development is divided into four general stages or phases, with a gradual transition from one to another. Each of the four stages is characterized by modes of learning and thinking unique to that stage.


4.     Because of the hierarchical nature of Piaget’s theory, thought and intelligence are rooted in the actions of the sensorimotor period, the first of the four stages of cognitive development. Thus, for Piaget, thought and intelligence are internalized actions.


5.     Throughout all of the stages, two “cognitive functions” are present that are invariant. These are organization and adaptation. The former is involved in the categorization of sensory data. The latter is comprised of assimilation, the taking in of new information, and accommodation, the adjusting of the existing knowledge to the new information.


6.     The result of the above invariant or unchanging functions is what Piaget refers to as “cognitive structures.” The cognitive structures are formed actively by each individual and contain all of the information that he has assimilated and accommodated or is in the process of adapting.


7.     The cognitive structures result in behaviors from which the content of the structures can be inferred. Therefore, Piaget refers to such responses as “cognitive content.” Since the cognitive structures vary in content from individual to individual according to personal experiences and level of maturation, the behaviors or cognitive content vary accordingly.


8.     As a result of the above, Piaget concludes that innate factors, environment, social transmission, and equilibration all play roles in what we know and in how we use our knowledge. For him, equilibration consists of the processes of equilibrium and disequilibrium which are in relative balance at all maturational levels, motivating us not only to assimilate and accommodate within stages but also to move from one stage to another. It is the disequilibrium that motivates us to learn and the return to equilibrium that leaves us at a higher level of learning.


Challenges to the theory

Piaget made many significant contributions to how people think about child development with his theory. However, it is not without criticisms, such as: