Cognitive Development

Piaget: Key ideas

Introduction to Piaget

Jean Piaget was employed at the Binet Institute in the 1920s, where his job was to develop French versions of questions on English intelligence tests. He became intrigued with the reasons children gave for their wrong answers on the questions that required logical thinking. Over the next fifty years, this curiosity led to the development of his theory of "genetic epistemology".

Piaget's theory differs from other theories in several ways:

  • It is concerned with children, rather than all learners.
  • It focuses on development, rather than learning per se, so it does not address learning of information or specific behaviours.
  • It proposes discrete stages of development, marked by qualitative differences, rather than a gradual increase in number and complexity of behaviours, concepts, ideas, etc.

The goal of the theory is to explain the mechanisms and processes by which the infant, and then the child, develops into an individual who can reason and think using hypotheses. To Piaget, cognitive development was a progressive reorganization of mental processes as a result of maturation and experience. Children construct an understanding of the world around them, and then experience discrepancies between what they already know and what they discover in their environment.

There are three basic components to Piaget's theory:

  • Types of knowledge (physical, logical-mathematical, and social-arbitrary)
  • Stages of development (sensorimotor, preoperational, concrete operational, formal operational)
  • Processes that enable the transition from one stage to another (assimilation, accommodation, and equilibration)

Piaget's proposed stages of development

An important thing to understand about these different levels is that they are qualitatively different. In other words, at each successive stage, it's not just a matter of doing something better, but of doing a different thing altogether.

The function of cognitive growth is to produce increasingly powerful cognitive structures that permit the individual to act on the environment with greater flexibility.

The sensorimotor period ranges from birth to about age 2. Infants learn mostly through trial and error learning. Children initially rely on reflexes, eventually modifying them to adapt to their world. Behaviours become goal directed, progressing from concrete to abstract goals. Objects and events can be mentally represented by the child (sometimes called object permanence). For example, if you place a toy under a blanket, the child who has achieved object permanence knows it is there and can actively seek it. Before this stage, the child behaves as if the toy had simply disappeared. The attainment of object permanence generally signals the transition to the next stage.

The preoperational period ranges from about ages 2 to 7. Children in this stage can mentally represent events and objects (the semiotic function), and engage in symbolic play. Their thoughts and communications are typically egocentric (i.e., about themselves). They are able to focus on only one aspect or dimension of problems. For example, suppose you arrange two rows of blocks in such a way that a row of 5 blocks is longer than a row of 7 blocks. Preoperational children can generally count the blocks in each row and tell you the number contained in each. However, if you ask which row has more, they will likely say that it is the one that makes the longer line, because they cannot simultaneously focus on both the length and the number. The ability to solve this and other "conservation" problems signals the transition to the next stage.

Children in the concrete operational period are typically ages 7 to 11. They gain the abilities of conservation (number, area, volume, orientation) and reversibility. Their thinking is more organized and rational. They can solve problems in a logical fashion, but are typically not able to think abstractly or hypothetically.

The formal operational period begins at about age 11. As adolescents enter this stage, they gain the ability to think in an abstract manner, the ability to combine and classify items in a more sophisticated way, and the capacity for higher-order reasoning.

Processes of development

The continual process of resolving the discrepancies they encounter moves the child's intelligence into a more mature understanding. Piaget used the concepts of assimilation and accommodation to explain this continual process.

When children and adolescents encounter something reasonably similar to what they already know, it is assimilated into their existing knowledge. So, for example, when small children put everything they grasp into their mouth, or call all small animals "dogs," they are assimilating.

On the other hand, when children encounter something that is different from what they know, they may change their way of thinking to take into account this new knowledge. This is accommodation.

According to Piaget, reorganization to higher levels of thinking is not accomplished easily. The child must "rethink" his or her view of the world. An important step in the process is the experience of cognitive conflict. In other words, the child becomes aware that he or she holds two contradictory views about a situation and they both cannot be true. This step is referred to as disequilibrium.

Equilibration is a regulatory process that maintains a balance between assimilation and accommodation to facilitate cognitive growth. Think of it this way: We can't merely assimilate all the time; if we did, we would never learn any new concepts or principles. Everything new we encountered would just get put in the same few "slots" we already had. Neither can we accommodate all the time; if we did, everything we encountered would seem new; there would be no recurring regularities in our world. We'd be exhausted by the mental effort!

According to Piaget, teaching can support these developmental processes by

  • Providing support for the "spontaneous research" of the child
  • Using active methods that require rediscovering or reconstructing "truths"
  • Using collaborative, as well as individual activities
  • Devising situations that present useful problems, and create disequilibrium in the child


Bruner: Key ideas


The outcome of cognitive development is thinking. The intelligent mind creates from experience "generic coding systems that permit one to go beyond the data to new and possibly fruitful predictions." Thus, children as they grow must acquire a way of representing the "recurrent regularities" in their environment. So, to Bruner, important outcomes of learning include not just the concepts, categories, and problem-solving procedures invented previously by the culture, but also the ability to "invent" these things for oneself.

Cognitive growth involves an interaction between basic human capabilities and "culturally invented technologies that serve as amplifiers of these capabilities." These culturally invented technologies include not just obvious things such as computers and television, but also more abstract notions such as the way a culture categorizes phenomena, and language itself. Bruner would likely agree with Vygotsky that language serves to mediate between environmental stimuli and the individual's response.

The aim of education should be to create autonomous learners (i.e., learning to learn).

Three modes of representation

Bruner hypothesized that the usual course of intellectual development moves through three stages: enactive, iconic, and symbolic, in that order. However, unlike Piaget's stages, Bruner did not contend that these stages were necessarily age-dependent, or invariant.

In the enactive stage, knowledge is stored primarily in the form of motor responses. And this is not just limited to children. Many adults can perform a variety of motor tasks (typing, sewing a shirt, operating a lawn mower) that they would find difficult to describe in iconic (picture) or symbolic (word) form.

In the iconic stage, knowledge is stored primarily in the form of visual images. This may explain why, when we are learning a new subject, it is often helpful to have diagrams or illustrations to accompany verbal information.

In the symbolic stage, knowledge is stored primarily as words, mathematical symbols, or in other symbol systems. According to Bruner's taxonomy, these differ from icons in that symbols are "arbitrary." (For example, the word "beauty" is an arbitrary designation for the idea of beauty in that the word itself is no more inherently beautiful than any other word.)

Assertions/implications for instruction

"Any subject can be taught effectively in some intellectually honest form to any child at any stage of development." No, Bruner probably would not contend that a one-year old could be taught astrophysics. But he might contend that kindergarteners could be taught some principles of physics (e.g., force, mass, momentum, friction) in enactive form. Later, these same principles could be repeated in iconic, then symbolic form.

The subject matter must be made "ready" for the child. Piaget and, to an extent, Ausubel, contended that the child must be ready, or made ready, for the subject matter. But Bruner contends just the opposite. According to his theory, the fundamental principles of any subject can be taught at any age, provided the material is converted to a form (and stage) appropriate to the child.

The instructional challenge is to provide problems that both fit the manner of the child's thinking and tempt him/her into more powerful modes of thinking. This is similar to Vygotsky's notion that learning should lead development.

The notion of enactive, iconic, and symbolic stages may also be applicable to adults learning unfamiliar material.

Modes of representation imply the ideal sequence for instruction, but when learners have well-developed symbolic systems, it may not be necessary to go through the entire sequence. Also, the mode of instruction should match the criteria that will be used for measuring learning outcomes.

The notion of a "spiral curriculum" embodies Bruner's ideas by "spiralling" through similar topics at every age, but consistent with the child's stage of thought.

Discovery is not just an instructional technique, but also an important learning outcome in itself. Schools should help learners develop their own ability to find the "recurrent regularities" in their environment. The teacher's job is to guide the discovery process. E.g., in teaching a particular concept, the teacher should present the set of instances that will best help learners develop an appropriate model of the concept. The teacher should also model the inquiry process. Bruner would likely not contend that all learning should be through discovery. For example, it seems pointless to have children "discover" the names of the U.S. Presidents, or important dates in history.

Educators should keep in mind that members of different cultures would exhibit different kinds of reasoning and inference.


Vygotsky: Key ideas

Major themes/assumptions/assertions

Vygotsky's theory is an explicit attempt to develop a Marxist psychology; i.e., the structure and practices of socially organized labour provide the context for how people act and think.

Vygotsky maintained a broader view of development than other theorists: how did humans come to develop higher psychological processes in the first place? Within that framework, how do children come to possess the cognitive functions they exhibit later in life?

Individual development cannot be understood without reference to the social and cultural context within which it is embedded. Higher mental processes in the individual have their origin in social processes.

Mental processes can be understood only if we understand the tools and signs that mediate them. In higher forms of human behaviour, the individual actively modifies the stimulus situation as a part of the process of responding to it.

No single principle (such as Piaget's equilibration) can account for development.

Appropriate methods for studying intellectual development are:

  • emphasis on experimentation/observation in natural, authentic settings
  • cross-species comparisons
  • sociohistorical factors that mediate development

The social origins of higher mental processes

Social context is so important to Vygotsky that it is not simply one more variable to be accounted for; rather, social activity (i.e., the interaction between individual and context), not the individual him/herself, is the appropriate unit of analysis in psychology.

Development does not proceed toward socialization; development is the conversion of social relations into mental functions. "Every function in the child's cultural development appears twice: first, on the social level, and later on the individual level; first, between people, then inside the child... All the higher functions originate as actual relations between individuals." For example, children may argue with each other about who gets to play with what toy, or how a task should be completed. Eventually, this argument among people gets converted to a kind of internal, mental "argument"; that is, it contributes to the ability to see an issue from different sides, and to weigh various courses of action before making a decision.  A shared understanding between two or more people is known as intersubjectivity and the process by which this is achieved is known as semiotic mediation.

The child converts social relations into psychological functions through mediation. Mediation occurs through a linking tool or sign. A tool is defined as something that can be used in the service of something else. A sign is something that stands for something else (indexical, iconic, symbolic). Language is the most important kind of sign use in acquisition of higher psychological processes, because it frees children from the constraints of their immediate environment (decontextualization). For example, a small child can respond only to its immediate needs or feelings: hunger, thirst, pain, fear, etc. But as adults, we can use language to regulate our behaviour beyond our immediate needs or environment. For example, in the morning I may wake up and want a glass of orange juice, only to discover that I am out of orange juice. Later in the day, I am no longer thirsty for orange juice, but I can mediate my behaviour through the use of a sign: that is, I can write "orange juice" on a grocery list and buy some on the way home. The use of this written sign allows me to regulate my own behaviour (that of buying orange juice) even when I am no longer experiencing the immediate environmental stimulus of thirst.

The diversity of symbols across cultures leads to differences in the kinds of mental functions that are developed. Thus, universal stages of psychological development across cultures cannot be identified. For example, people of different cultures have been shown to classify objects in different ways. One culture might group plants according to their use; another according to their appearance, another according to their location, etc.

Implications for instruction

Instruction should lead (i.e., precede) development. It should be targeted at the "leading" edge of the zone of proximal development. The zone of proximal development (ZPD) is defined as the difference between problem-solving the child is capable of performing independently, and problem-solving he/she is capable of performing with guidance or collaboration. This defines the area in which maturation/development is currently taking place and suggests the appropriate target for instruction. For example, suppose a particular 9-year old can solve most arithmetic problems independently; can solve some simple algebraic problems with guidance from a teacher; and cannot solve calculus problems no matter how much help she is given. We would say that algebra problems are within her ZPD, and that this is the level at which instruction would be most profitable. After all, it will be of little use to continue to present problems that she can already solve, or to present problems that will only frustrate her.

In an instructional setting, social "partners" should be at different levels of development, and they should jointly construct the problem solution. This helps to insure that the teacher or more advanced student can assist the less advanced one, and that they will be operating within his/her ZPD.

Instruction should provide learners with authentic situations in which they must resolve dilemmas. From Vygotsky's perspective, the child has not yet learned to operate at an entirely abstract level; thus, instruction should focus on tasks and goals that are relevant to the child. After all, according to Vygotsky, the very origin of human thought is in socially meaningful activity.

Individualized testing (which is generally the only kind we do) can give only a partial picture of the child's capabilities since it fails to account for the ZPD.

Current applications of Vygotsky's work

A contemporary application of Vygotsky's theories is "reciprocal teaching", used to improve students' ability to learn from text. In this method, teacher and students collaborate in learning and practicing four key skills: summarizing, questioning, clarifying, and predicting. The teacher's role in the process is reduced over time. Also, Vygotsky is relevant to instructional concepts such as "scaffolding" and "apprenticeship", in which a teacher or more advanced peer helps to structure or arrange a task so that a novice can work on it successfully.

Vygotsky's theories also feed into current interest in collaborative learning, suggesting that group members should have different levels of ability so more advanced peers can help less advanced members operate within their ZPD.



Key Concepts

Role of Language

Role of individual in the learning process (i.e. active or passive)

Role of maturation (when is a child ready to learn?)

Curriculum (what should be taught?)

Teaching styles (How should the curriculum be taught?)






















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