Piaget’s Stages: 4 Stages of Cognitive Development & Theory

Piaget's Stages Have you ever experienced the following?

You’re trying to explain something to a child, and even though it seems so obvious to you, the child just doesn’t seem to understand.

They repeat the same mistake, over and over, and you become increasingly frustrated.

Well, guess what?

  • The child is not naughty.
  • They’re also not stupid.
  • But their lack of understanding is not your fault either.

Their cognitive development limits their ability to understand certain concepts. Specifically, they’re not capable right now of understanding what you’re trying to explain.

In this post, we’ll learn more about Jean Piaget, a famous psychologist whose ideas about cognitive development in children were extremely influential. We’ll cover quite a lot in this post, so make sure you have a cup of coffee and you’re sitting somewhere comfortable.

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Who Was Jean Piaget in Psychology?

Jean Piaget was a Swiss psychologist who contributed greatly to the understanding of children’s cognitive development (Papalia & Feldman, 2011; Waite-Stupiansky, 2017).

He was born in 1896 and originally trained as a biologist and philosopher. Although he is well known for his work as a psychologist, he also published research on sparrows and mollusks (Burman, 2012; Papalia & Feldman, 2011; Waite-Stupiansky, 2017).

Piaget’s contribution to psychology was mainly through his observations of children’s cognitive development (Papalia & Feldman, 2011). Early in his career, Piaget scored the IQ tests that Alfred Binet administered to children.

Piaget noticed that children of certain ages tended to give the same types of incorrect answers. From these observations and follow-up interviews with children about these mistakes, he developed a theory of how children’s cognitive processes developed (Waite-Stupiansky, 2017).

One of the most important implications of his work is that children are not born with the same cognitive processes as adults (Papalia & Feldman, 2011). Instead, children’s cognitive processes:

  • develop over time,
  • develop in response to their environment, and
  • are updated with exposure to new information.

Piaget also influenced psychology in other ways. For example, he emphasized other methods of conducting research, such as the clinical method (Papalia & Feldman, 2011; Waite-Stupiansky, 2017). He relied upon the following research methods:

  1. Naturalistic observation of play and conversation between children (including his own)
  2. Interviewing children

Additionally, he was the first psychologist to study ‘theory of mind’ in children (Papalia & Feldman, 2011). Theory of mind is the understanding or basic sense that each of us has our own consciousness and thoughts.

Piaget’s Cognitive Development Theory

Cognitive Development TheoryPiaget argued that children’s cognitive development occurs in stages (Papalia & Feldman, 2011).

Specifically, he posited that as children’s thinking develops from one stage to the next, their behavior also changes, reflecting these cognitive developments.

The stages in his theory follow a specific order, and each subsequent stage only occurs after the one before it.

These stages are:

  • Sensorimotor stage (0–2 years old)
  • Preoperational stage (2–7 years old)
  • Concrete operational stage (7–11 years old)
  • Formal operational stage (11 years old through adulthood)
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1. The Sensorimotor Stage

The sensorimotor stage is the first phase of children’s cognitive development. During this stage, children primarily learn about their environment through their senses and motor activities.

The sensorimotor stage comprises six substages, where children’s behavior moves from being reflex driven to more abstract. Each substage is described briefly.

1. Use of reflexes (0–2 months)

During this stage, children typically use their reflexes. They cannot consolidate information from their sensory organs into a single, unified concept.

2. Primary circular reactions (1–4 months)

Children start to consolidate information from different sensory organs. They start to engage in behavior that satisfies the way their body feels or their needs. For example, they repeat pleasurable behaviors, and they adapt their behavior to feed from different objects. They turn to respond to sounds and sights in their environment.

3. Secondary circular reactions (4–8 months)

Children’s behaviors become more intentional, and the types of behaviors that they repeat expand to include those that result in interesting responses external to their body. For example, they might push buttons on a toy. Children also start to take more interest in their environment. They repeat behaviors that generate interesting responses.

4. Coordination of secondary schemes (8–12 months)

At this point, children’s behaviors become more goal oriented, and they can combine different behaviors to achieve goals.

5. Tertiary circular reactions (12–18 months)

Instead of performing the same actions, children try new behaviors and actions to achieve different results. These behaviors are not spontaneous or by accident, but are purposeful. Unlike primary and secondary reactions, children can combine more complicated behaviors and even perform a behavior similarly but not the same to get the desired result.

6. Mental combinations (18–24 months)

Children start to rely on mental abstractions to solve problems, use gestures and words to communicate, and can pretend. Instead of relying on numerous attempts to solve problems/puzzles, children can deliberate and carefully choose their actions.

2. The Preoperational Stage

Preoperational StageAt the end of the sensorimotor stage, children start to use mental abstractions.

At the age of two, children enter the preoperational stage, where their ability to use mental representations, rather than the physical appearance of objects or people, improves greatly.

Examples of abstract representations include engaging in pretend play and talking about events that happened in the past or people who are not currently in the room.

Other interesting cognitive advances occur during this phase. For example, children understand causality. Children also understand identities, where items and people remain the same even if they look different. For example, at some point during this stage, a caregiver dressing up as Santa Claus might not be as convincing.

In this stage, children also learn more about categorization. They can classify items based on similarities or differences. They also start to understand numbers and quantity (e.g., concepts such as ‘more’ or ‘bigger’).

Although abstract thought advances quickly in the preoperational stage, other cognitive processes develop more slowly.

For example:

  • Children tend to consider their own viewpoint and perspective.
  • Children fail to understand that two things can be the same, even if they appear different (more about this in the next section on Conservation).
  • Children struggle to take someone else’s point of view.

3. The Concrete Operational Stage

The next phase is the concrete operational stage, which begins around the age of seven. During this stage, children are more capable of solving problems because they can consider numerous outcomes and perspectives. All of their cognitive abilities are better developed in this stage.

  • Categorization abilities improve so that children can arrange items along a dimension, understand that categories have subcategories, and relate two objects to each other through a third object.
  • Their numerical abilities improve a lot, and they can perform more complicated mathematical operations.
  • Their spatial abilities are better. They are better at estimating time and distance. They can read maps and describe how to navigate from one location to another.


During this stage, children understand the concept of conservation better and, as a result, are better at solving conservation problems. Conservation refers to the idea that things can be the same, even if they look different.

An example would be a cup of water poured into two glasses. One glass is tall and thin, while the other is short and wide. Recognizing that both glasses contain the same amount of water shows an understanding of conservation.

Children in the preoperational stage struggle with problems of conservation. For example, they struggle with tasks where the following is conserved even it appears different:

  • Number of items (e.g., two sets of 10 items arranged differently)
  • The volume of liquid (e.g., the same volume of liquid in two differently shaped glasses)

Children struggle with conservation because they can only focus on one dimension at a time; this is known as centering. For example, with the volume of liquid, they can only consider the shape of the glass, but not the shape of the glass and the volume of water.

They also do not yet understand reversibility. Irreversibility refers to a child’s inability to reverse the steps of an action in their mind, returning an object to its previous state. For example, pouring the water out of the glass back into the original cup would demonstrate the volume of the water, but children in the preoperational stage cannot understand this.

In contrast, children in the concrete operational stage can solve conservation problems. This is because children now have the following cognitive abilities:

  • They understand reversibility (i.e., items can be returned to original states).
  • They can decenter (i.e., concentrate on multiple dimensions of items, rather than just one).
  • They better understand identity (i.e., an item remains the same even if it looks different).

4. The Formal Operational Stage

Formal Operational StageAt the age of 11, children enter the formal operational stage.

Abstract thought characterizes this stage. Children can think about abstract concepts and are not limited to a current time, person, or situation.

They can think about hypothetical situations and various possibilities, like situations that don’t exist yet, may never exist, or might be unrealistic and fantastical.

During this stage, children are capable of hypothetical-deductive reasoning, which allows them to test hypotheses and draw conclusions from the results. Unlike younger children who haphazardly approach problems, children in the formal operational stage can apply their reasoning skills to apply more complicated problems in a systematic, logical manner.

Piaget’s Theory vs Erikson’s

Piaget’s theory of cognitive development is one of several theories about how children develop. Other contrasting theories include Vygotsky’s sociocultural theory, Freud’s psychoanalytic theory, and importantly for this post, Erikson’s psychosocial theory of development.


Unlike Piaget, who focused on cognitive development, Erikson emphasized healthy ego development (Papalia & Feldman, 2011). Healthy egos are developed when people resolve specific personality issues at set periods in their lives.

Specifically, each developmental stage is characterized by two conflicting personality traits, one positive and one negative. Successful resolution occurs when the positive trait is more emphasized than the other, resulting in the development of a virtue, which aids healthy resolution of subsequent stages.

As an example, between 12 and 18 months, children experience two feelings: trust and mistrust. If they resolve this crisis by balancing a healthy level of trust with mistrust, then they develop the virtue of ‘hope.’

Overall, Erikson proposed eight personality crises, five of which occur before the age of 18:

  • Basic trust versus mistrust ( 0–12/18 months)
  • Autonomy versus shame and doubt (12/18 months–3 years)
  • Initiative versus guilt (3–6 years)
  • Industry versus inferiority (6 years–puberty)
  • Identity versus identity confusion (puberty–young adulthood)

Not all of the developmental stages in Erikson’s theory correspond to the cognitive stages proposed by Piaget. For example, Piaget’s preoperational stages overlap with the second and third stages in Erikson’s theories.


Like Piaget, Erikson also emphasized that children’s development occurs through interacting with the external environment, but Erikson’s stages focus more on societal influences. Both Piaget and Erikson emphasized that children are active participants in their world and that development occurs in stages.

5 Important Concepts in Piaget’s Work

Schemas and constructivismSeveral concepts are pivotal to Piaget’s theory of cognitive development.

Schemas and constructivism

Piaget argued that children learn about the world by interacting with it. This notion of gaining knowledge about the world is known as constructivism (Waite-Stupiansky, 2017).

Through their interactions, children construct schemas – or cognitive patterns – about how the world works (Waite-Stupiansky, 2017). These schemas come about through organization, which is how categories are formed, organizing items together based on common characteristics.

According to Piaget schemas can then be repeated and tested. For example, an infant has a schema about a rattle: shake it, and it makes a noise.

Importantly, schemas are not static, and they can be improved and updated with new information. When children learn new information, they do not disregard their previous schemas; instead, they build upon them. As a result, children’s cognitive development happens in stages as schemas are continuously updated with new information.


Adaptation describes how children update their current cognitive organizations and schemas with new information. Adaptation takes place in two ways: assimilation and accommodation.


Assimilation describes how children incorporate new information into existing schemas. For example, a child refers to dogs as ‘woofs.’ When they see a cat for the first time, they refer to the cat as a ‘woof’ too.


Accommodation describes how children adapt their cognitive structures to match new information in the world. Continuing with the previous example, the child realizes that dogs and cats are different. The child updates their cognitive schema of the world, and now refers to cats as ‘cats’ and dogs as ‘woofs’.


Piaget’s background as a biologist influenced some of his work, notably the concept of ‘equilibrium,’ which resembles homeostasis (Waite-Stupiansky, 2017). He posited that children’s cognitive processes are aimed toward equilibrium. When children learn new information that is at odds with their current schemas, they are in an undesirable state of disequilibrium.

To achieve equilibrium, children adapt their mental instructions by:

  1. Assimilating new information
  2. Accommodating new information by updating their cognitive schemas

By achieving equilibrium, children learn new information.


Piaget’s Theory of Cognitive Development

Applications in Education (+3 Classroom Games)

One premise of constructivism is that knowledge about the world is gained and made sense of through active participation. In other words, children are not passive recipients of knowledge. They’re not empty vessels waiting to be filled with knowledge. Instead, children’s knowledge is generated when they interact with the world (Yilmaz, 2008).

Some of the education implications of this concept are that children cannot be expected to ‘just sit down and learn’ and that teaching methods that emphasize passive learning are discouraged.

An example of passive learning is reading a text without engaging with it, debating with it, or trying to connect it to real life. Instead, teaching rooted in Piaget’s theories emphasizes that children learn by interacting. Here are some examples:

  • Physical interaction (e.g., seeing and touching insects when learning about them)
  • Verbal interaction (e.g., talking about how new learning material connects to everyday experiences)
  • Abstract interaction (e.g., thinking about new ideas, wrestling with difficult or challenging topics, imitating or acting out concepts/ideas/people)

Play theory

Piaget (1951) argued that play is vital for children’s learning. Play is an example of assimilation, and imitation is an example of accommodation.

He argued that there are three types of games that children can play based on their cognitive development:

  1. Practice games
  2. Symbolic games
  3. Games with rules

Practice games include the repetition of a particular set of actions for pure enjoyment. Although it might not seem like much, these practice games are very important for cognitive development.

Symbolic games involve make-believe scenarios and characters, and appear during the preoperational stage.

Rule-based games appear later during the concrete operational stage. As well as abstract elements, these games also include rules and consequences for violating them.

Classroom games

It’s important to tailor classroom games to match the overall development stage of the children.

For very young children in the sensorimotor stage, classroom games that rely on repetition and interesting results are best. In these games, the child repeatedly demonstrates a new skill or behavior that they have learned, reinforcing the behavior. Examples include splashing water, kicking leaves, shaking a rattle or toys, and playing with music instruments.

For children in the preoperational stage, classroom games that involve imitation are useful ways to teach new concepts. For example, children can learn about animals by pretending to be different animals (e.g., ‘roar like a lion,’ ‘jump like a frog’).

Children can also learn about social skills and social interactions by acting out certain social situations, like pretending to be a shopkeeper. Symbolic games are also used when children pretend one item is something else; for example, pretending that a stick is a lightsaber.

Rule-based games are more suitable for older children. These games can teach concepts like theory of mind, because they encourage decentering (DeVries & Kamii, 1975).

For example, in ‘Simon Says,’ children learn to watch the teacher and know that if they don’t follow the teacher, they are out. Typically, young children don’t understand rule-based games and are not good at counting or numbers.

This is why, for example, very young children don’t understand that there is a penalty for one child in ‘Musical Chairs’ (DeVries & Kamii, 1975). Young children will enjoy the game if the penalty is removed and the chairs stay the same.

Other ways that games can facilitate learning is by allowing children to make up the rules (DeVries & Kamii, 1975). New toys related to the concepts that they’re learning about should be available when children engage in unstructured play without the assistance of the teacher.

For more on this, we recommend reading our article How to Promote Cognitive Development: 23 Activities & Games.

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The Nice Things tool is useful in teaching children compassion. Children are encouraged to recall something ‘nice.’ It could be something nice that happened to them or something nice that they did. Children are also encouraged to share these nice things with each other and the class.

Since this task requires that children have mental/abstract representations of other people and things, it is more applicable for children in the preoperational and concrete operational stages.

In the Shuffle game, children learn how to resolve conflict. In this game, the play area is marked out with a set of items. Each child starts at one item, and an extra player is in the middle. At the start of the game, children have to move to another item.

However, if two children reach the same item simultaneously, they resolve this by playing Rock–Paper–Scissors. Since this is a rule-based game, it is best suited to children in the concrete operational stage; younger children will not understand the consequences of losing Rock–Paper–Scissors.

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A Take-Home Message

Knowing that children’s learning and understanding are limited by their cognitive development, what can you do the next time you explain something?

  1. Use simple, age-appropriate examples.
  2. Explain concepts simply, considering the limitations of each cognitive stage.
  3. Encourage discussion and creativity so that they create meaningful interactions and memories.

Most importantly, remember that children are not born as ‘mini-adults.’ They do not have adult cognitive abilities, and they do not have the lifetime of experiences for these abilities to develop.

Instead, to learn, they need to participate actively with their world and the people in it. They must be exposed to new experiences and information for learning to occur, and importantly, they must have the opportunities to make mistakes.

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  • Burman, J. T. (2012). Jean Piaget: Images of a life and his factory. History of Psychology, 15(3), 283–288.
  • DeVries, R., & Kamii, C. (1975). Why group games? A Piagetian perspective. ERIC Clearinghouse.
  • Papalia, D. E., & Feldman, R. D. (2011). A child’s world: Infancy through adolescence (12th ed.). McGraw-Hill.
  • Piaget, J. (1951). Play, dreams and imitation in childhood (vol. 25). Routledge.
  • Waite-Stupiansky, S. (2017). Jean Piaget’s constructivist theory of learning. In L. E. Cohen & S. Waite-Stupiansky (Eds.), Theories of early childhood education: Developmental, behaviorist, and critical (pp. 3–17). Routledge.
  • Yilmaz, K. (2008). Constructivism: Its theoretical underpinnings, variations, and implications for classroom instruction. Educational Horizons, 86(3), 161–172.


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