Piaget’s stages of intellectual development | AQA A-Level Psychology Revision

For 7182 specification, first teach in September 2025

AQA A-Level Psychology | Free Revision Notes

Estimated study time: 60 minutes

Piaget proposed that children progress through a sequence of stages, with each stage characterised by a different type of thinking. These Piaget’s stages of intellectual development A-Level Psychology revision notes cover the sensorimotor, pre-operational, concrete operational and formal operational stages.

Across the stages, thinking develops from physical action and immediate sensory experience towards symbolic, logical and abstract reasoning. The lesson builds on schemas, assimilation, accommodation and equilibration and introduces the developmental changes behind object permanence and conservation and egocentrism and class inclusion. AQA requires knowledge of Piaget’s stages and their characteristics, including object permanence, conservation, egocentrism and class inclusion.

Learning Objectives 🎯

By the end of this revision page, you should be able to:

• Name Piaget’s four stages of intellectual development in the correct order.

• Describe the approximate age range and characteristics of each stage.

• Explain how thinking changes from action-based to abstract reasoning.

• Apply the stages to unfamiliar descriptions of children’s behaviour.

• Distinguish object permanence, egocentrism, conservation and class inclusion.

• Evaluate whether cognitive development occurs through fixed, universal stages.

Revision Notes 📚

Piaget’s stages of intellectual development overview

Piaget proposed four major stages of intellectual development:

1. Sensorimotor stage

2. Pre-operational stage

3. Concrete operational stage

4. Formal operational stage

The stages represent qualitative differences in thinking.

A qualitative change is a change in the type or structure of thought, rather than simply an increase in the amount a child knows.

For example:

• An infant understands the world mainly through physical actions.

• A young child can use words and symbols but remains influenced by appearances.

• An older child can reason logically about concrete situations.

• An adolescent can consider abstract and hypothetical possibilities.

Overview of the stages

Stage	Approximate age	Central characteristics
Sensorimotor	Birth to 2 years	Learning through senses and physical action, intentional behaviour, object permanence and early symbolic thought
Pre-operational	2 to 7 years	Symbolic thought and language, egocentrism, centration and lack of conservation
Concrete operational	7 to 11 years	Logical reasoning about concrete information, conservation, decentration and class inclusion
Formal operational	Approximately 11 years onwards	Abstract, hypothetical and systematic reasoning

The ages are approximate. They should not be treated as exact birthdays on which a child suddenly changes how they think.

What makes Piaget’s account a stage theory?

A stage theory proposes that development occurs through a sequence of qualitatively different forms of thought.

Piaget’s stages have several important features.

The stages occur in a fixed order

Children progress from:

sensorimotor → pre-operational → concrete operational → formal operational

A child does not normally reach formal operational reasoning before developing concrete operational thought.

Each stage has characteristic thinking

Children within a stage tend to display related cognitive abilities and limitations.

For example, a child in the pre-operational stage may:

• Use symbols.

• Engage in pretend play.

• Remain egocentric.

• Fail conservation tasks.

Later stages build on earlier development

Earlier abilities are not completely lost.

Instead, they become incorporated into more complex forms of understanding.

A concrete operational child can still use symbols, but can also apply logical operations to concrete information.

Development involves qualitative change

Piaget did not simply claim that older children know more facts.

He proposed that they think in a different way.

For example:

• A pre-operational child may judge quantity from appearance.

• A concrete operational child can mentally reverse the transformation and understand conservation.

Movement is linked with maturation and experience

Cognitive development involves:

• Biological maturation.

• Active exploration.

• Assimilation.

• Accommodation.

• Equilibration.

The child constructs increasingly advanced schemas through interaction with the environment.

Stage 1: The sensorimotor stage

Age range

The sensorimotor stage lasts from birth to approximately 2 years.

It is Piaget’s first stage of intellectual development.

AQA’s 2025 mark scheme identifies the sensorimotor period as occurring from birth to 2 years and describes characteristic developments including reflexes, trial-and-error learning, intentional behaviour, object permanence and symbolic function.

Why is it called sensorimotor?

The word combines:

• Sensory, involving sight, sound, touch, taste and other sensations.

• Motor, involving physical movement and action.

Infants initially understand the world by:

• Looking.

• Grasping.

• Sucking.

• Reaching.

• Shaking.

• Kicking.

• Moving objects.

Their knowledge is based mainly on what they can currently sense and do.

Early reflexes

At the beginning of the stage, behaviour is dominated by reflexes.

Examples include:

• Sucking.

• Grasping.

• Looking.

• Responding to sensations.

These simple actions form the beginnings of behavioural schemas.

For example, an infant may initially grasp automatically when something touches their hand.

Through repeated experience, grasping becomes increasingly deliberate and adapted to different objects.

Circular reactions

Infants repeat actions that produce interesting or pleasurable consequences.

For example:

An infant accidentally hits a rattle and hears a sound. The infant gradually learns to repeat the arm movement to produce the sound again.

The repeated action helps the infant develop a schema connecting:

• Movement.

• The object.

• The resulting sound.

Trial-and-error learning

The infant experiments with actions and observes what happens.

For example, an infant may:

• Shake one toy.

• Drop another.

• Bang two objects together.

• Pull a cloth to move an object.

• Repeat actions that produce interesting results.

Piaget viewed these actions as early scientific exploration.

Intentional behaviour

At first, many actions occur accidentally.

Later, the infant becomes capable of acting deliberately to produce a desired result.

AQA’s 2025 mark scheme identifies intentional behaviour at approximately eight months, such as deliberately throwing an object so that another person retrieves it.

Intentional behaviour shows that:

• The infant can connect actions with outcomes.

• Behaviour is becoming goal directed.

• The child can coordinate more than one schema.

Object permanence

Object permanence is the understanding that objects and people continue to exist when they cannot be seen.

A very young infant may appear to behave as though a hidden object has ceased to exist.

Later, the infant searches for an object that has been covered or hidden.

Piaget placed the development of object permanence at approximately eight to nine months.

For example:

A toy is placed beneath a cloth while the infant watches. The infant lifts the cloth and searches for it.

The search indicates that the infant has developed a mental representation of the hidden object.

Object permanence is examined in greater detail in Piaget’s hiding tasks and conservation research.

The A-not-B error

An infant may repeatedly retrieve an object from location A.

The researcher then moves the object to location B while the infant watches.

The infant may continue searching at location A.

This is known as the A-not-B error.

Piaget interpreted the error as evidence that the infant’s mental representation of the object was not yet fully developed.

Symbolic function

Near the end of the sensorimotor stage, children begin to develop symbolic function.

Symbolic function is the ability to understand that one thing can represent another.

For example:

• A word represents an object.

• A photograph represents a person.

• A toy block represents a car during play.

This development prepares the child for the symbolic thinking of the pre-operational stage.

Egocentrism in infancy

Piaget regarded infants as highly egocentric.

At this stage, the child does not yet understand perspectives separate from their own immediate sensory experience.

This early egocentrism should not be confused with selfishness.

It concerns a cognitive inability to represent another person’s viewpoint.

Sensorimotor thinking summarised

Early in the stage	Later in the stage
Reflexive actions	Intentional, goal-directed actions
Knowledge tied to immediate sensations	Mental representation begins
Accidental effects	Deliberate repetition
Limited search for hidden objects	Object permanence develops
Mainly action-based schemas	Early symbolic function

Applying the sensorimotor stage

Four-month-old Isla repeatedly kicks her legs because this makes a hanging toy move. Eleven-month-old Theo watches his father hide a ball beneath a cushion and immediately searches for it.

Piaget would explain that:

• Isla is learning through sensory and motor action.

• Her repeated kicking is a circular reaction.

• She is developing a schema connecting movement with the toy’s motion.

• Theo’s search demonstrates object permanence.

• Theo is able to form a mental representation of the unseen ball.

• Both children are in the sensorimotor stage, but Theo demonstrates a later ability.

Stage 2: The pre-operational stage

Age range

The pre-operational stage lasts from approximately 2 to 7 years.

The term “pre-operational” means that the child cannot yet perform the logical mental operations associated with later development.

The child can think symbolically but does not yet reason logically and consistently about transformations.

Symbolic thought

Children become increasingly able to use symbols.

Examples include:

• Language.

• Drawings.

• Images.

• Pretend objects.

• Imaginative play.

A child might:

• Use a cardboard box as a pretend boat.

• Treat a stick as a sword.

• Draw a picture representing their family.

• Use words to describe an absent object.

The child no longer depends entirely on direct physical action.

Language development

Rapid language growth allows the child to:

• Name objects.

• Describe events.

• Ask questions.

• Express ideas.

• Represent past and future experiences.

However, possessing words does not mean that the child can reason logically about every problem.

The child may explain an event verbally while still being misled by appearances.

Pretend play

Symbolic thought supports imaginative play.

For example:

• A child pretends to feed a doll.

• A toy car represents a real vehicle.

• A group of chairs becomes a train.

Pretend play demonstrates the child’s ability to represent objects and roles mentally.

Egocentrism

Egocentrism is the inability to understand a situation from another person’s point of view.

A pre-operational child may assume that other people:

• See what they see.

• Know what they know.

• Feel what they feel.

• Understand the same information.

This does not mean the child is deliberately inconsiderate.

The child has difficulty mentally separating their own perspective from someone else’s.

The three mountains task

Piaget used the three mountains task to investigate egocentrism.

The child viewed a model containing three mountains from one position.

The child was then asked to select the view that would be seen by a doll placed at another position.

Younger children often selected their own view rather than the doll’s view.

Piaget concluded that they could not yet take another visual perspective.

This ability is examined more fully in perspective-taking and class inclusion tasks.

Centration

Centration is the tendency to focus on one noticeable feature of a situation while ignoring other relevant features.

For example, when liquid is poured into a taller, thinner container, a child may focus only on height.

The child ignores the fact that:

• The new container is narrower.

• No liquid was added.

• No liquid was removed.

Centration contributes to failure on conservation tasks.

Lack of conservation

Conservation is the understanding that a quantity remains the same despite a change in appearance.

A child may be shown two equal rows of counters.

The researcher spreads one row out.

A pre-operational child may say the longer row has more counters.

The child focuses on the length of the row and fails to consider:

• The spacing.

• The number of counters.

• The fact that nothing was added or removed.

AQA defines conservation as understanding that properties such as number, mass and volume remain constant despite changes in appearance.

Irreversibility

Pre-operational children often struggle to mentally reverse an action.

For example, after liquid is poured into a tall container, the child may not imagine pouring it back into the original glass.

If the child could mentally reverse the process, they might recognise that the quantity must be unchanged.

Class inclusion difficulty

Class inclusion involves understanding that a smaller category can be part of a larger category.

For example, a child is shown:

• Seven wooden beads.

• Three glass beads.

All ten objects are beads.

When asked whether there are more wooden beads or more beads altogether, a pre-operational child may answer “wooden beads”.

The child focuses on the visually dominant subclass and fails to understand its relationship with the whole category.

Pre-operational thinking summarised

Ability	Characteristic
Symbolic thought	Words, pictures and objects can represent other things
Language	Rapidly developing but not equal to logical reasoning
Egocentrism	Difficulty understanding another person’s viewpoint
Centration	Focus on one feature
Conservation	Usually not yet achieved
Reversibility	Difficulty mentally undoing a transformation
Class inclusion	Difficulty understanding subclasses within broader categories

Applying the pre-operational stage

Five-year-old Maya watches equal amounts of juice being poured into two identical glasses. The juice from one glass is then poured into a taller, narrower glass. Maya says the taller glass contains more juice.

Piaget would explain that:

• Maya is in the pre-operational stage.

• She focuses on the height of the liquid.

• This demonstrates centration.

• She does not consider the narrower width.

• She cannot mentally reverse the pouring process.

• She therefore fails to conserve volume.

Stage 3: The concrete operational stage

Age range

The concrete operational stage lasts from approximately 7 to 11 years.

The child becomes capable of logical mental operations, but this reasoning works most successfully with concrete information.

Concrete information concerns objects, events or examples that are real, visible or familiar.

Logical operations

An operation is a mental action that follows logical rules.

The concrete operational child can:

• Organise information.

• Compare quantities.

• Consider several features.

• Mentally reverse transformations.

• Classify objects.

• Understand relationships.

The child’s reasoning becomes more systematic than during the pre-operational stage.

Conservation

Children in this stage typically understand that quantities remain unchanged despite transformations in appearance.

They may conserve:

• Number.

• Length.

• Mass.

• Volume.

For example, a child understands that spreading counters apart does not change their number.

Decentration

Decentration is the ability to consider more than one relevant feature of a situation.

In the liquid task, the child considers:

• Height.

• Width.

• The transformation.

• The absence of addition or removal.

Decentration helps overcome the appearance-based judgement of the pre-operational stage.

Reversibility

Reversibility is the ability to mentally reverse an operation.

A child may reason:

“If the liquid were poured back into the original glass, it would reach the same level.”

This understanding supports conservation.

Identity

The child may recognise that the substance itself has not changed.

For example:

• It is the same liquid.

• Nothing has been added.

• Nothing has been removed.

The change is in appearance rather than quantity.

Compensation

The child can recognise that one change may be compensated for by another.

For example:

The liquid is higher in the second glass, but the glass is also narrower.

The two dimensions compensate for one another.

Class inclusion

Concrete operational children understand relationships between:

• A whole category.

• Its smaller subcategories.

For example, if there are seven wooden beads and three glass beads, the child understands that there are:

• More beads altogether than wooden beads.

• Ten members of the larger class.

• Seven members of one subclass.

The child can mentally hold the subclass and the larger class in mind simultaneously.

Classification

Children become better at organising objects according to shared characteristics.

They may classify objects by:

• Colour.

• Size.

• Shape.

• Material.

• Function.

They can also understand that the same object may belong to several categories.

For example, a dog may be classified as:

• A dog.

• A mammal.

• An animal.

• A pet.

Seriation

Seriation is the ability to arrange objects in a logical order.

For example, the child may order sticks from:

• Shortest to longest.

• Lightest to heaviest.

• Smallest to largest.

This requires comparison across the whole set rather than focusing on one object at a time.

Transitive inference

The child may understand logical relationships such as:

If A is longer than B, and B is longer than C, then A must be longer than C.

This reasoning is easier when the child can see or imagine concrete objects.

Limitation to concrete situations

The concrete operational child may struggle when reasoning requires purely abstract or hypothetical thought.

For example, the child may solve:

“Lena has more sweets than Jamal, and Jamal has more than Rob. Who has the most?”

but struggle with an unfamiliar logical problem containing abstract symbols.

The child can reason logically, but often needs information connected to concrete experience.

Concrete operational thinking summarised

New ability	Effect on thinking
Decentration	Several features can be considered
Reversibility	Transformations can be mentally undone
Conservation	Quantity is separated from appearance
Class inclusion	Subclasses are understood within larger classes
Classification	Objects can be organised using logical categories
Seriation	Objects can be arranged in order
Concrete logic	Reasoning is strongest with real or familiar information

Applying the concrete operational stage

Eight-year-old Zain is shown ten flowers, seven roses and three tulips. When asked whether there are more roses or more flowers, Zain answers that there are more flowers.

Piaget would explain that:

• Zain demonstrates class inclusion.

• He understands that roses form a subclass of flowers.

• He can consider the seven roses and the larger group of ten flowers.

• This logical classification is characteristic of the concrete operational stage.

Stage 4: The formal operational stage

Age range

The formal operational stage begins at approximately 11 years and continues into adulthood.

According to Piaget, the individual becomes capable of reasoning about ideas that are not directly tied to visible objects or immediate experience.

Abstract thinking

Abstract thinking involves reasoning about ideas that cannot necessarily be seen or physically handled.

Examples include:

• Justice.

• Freedom.

• Morality.

• Infinity.

• Political systems.

• Scientific theories.

An individual can consider the meaning of a concept rather than needing a concrete example.

Hypothetical reasoning

Hypothetical reasoning involves thinking about situations that may not be true or may never occur.

For example:

• “What would happen if gravity suddenly became weaker?”

• “How might society change if money did not exist?”

• “What evidence would disprove this theory?”

The individual can explore possibilities beyond present reality.

Hypothetico-deductive reasoning

Hypothetico-deductive reasoning involves:

1. Generating possible explanations.

2. Forming a hypothesis.

3. Deducting a prediction.

4. Testing the prediction systematically.

5. Using the evidence to accept or reject the explanation.

This resembles scientific reasoning.

Systematic problem-solving

Younger children may approach a problem through unsystematic trial and error.

Formal operational thinkers can vary one factor at a time and compare outcomes.

They may:

• Identify variables.

• Keep other conditions constant.

• Record results.

• Compare possible explanations.

• Draw conclusions logically.

Reasoning about possibilities

Formal operational thought allows the individual to distinguish:

• What is currently true.

• What might be possible.

• What must logically follow.

• What would occur under different conditions.

Reality becomes one possible outcome among several alternatives.

Propositional reasoning

Propositional reasoning involves evaluating the logic of a statement independently of whether its content matches everyday reality.

For example:

All creatures on planet X are blue. Nara is a creature on planet X. Therefore, Nara is blue.

The person can recognise that the conclusion follows logically from the premises, even though planet X is imaginary.

Metacognition

Metacognition means thinking about one’s own thinking.

An adolescent may become more able to:

• Evaluate their reasoning.

• Select a problem-solving strategy.

• Recognise weaknesses in an argument.

• Consider how they reached a conclusion.

Although metacognitive skills continue developing, formal reasoning supports this greater reflection.

Formal operational thinking summarised

Ability	Example
Abstract reasoning	Discussing justice or morality
Hypothetical thought	Considering situations that do not currently exist
Deductive reasoning	Drawing a logical conclusion from premises
Systematic testing	Varying one factor at a time
Possibility thinking	Comparing several potential outcomes
Metacognition	Reflecting on one’s own reasoning

Applying the formal operational stage

A science teacher asks pupils why plants near a window grow more quickly. Erin suggests several possible explanations, designs tests that alter one variable at a time and predicts the result of each test.

Piaget would explain that:

• Erin demonstrates formal operational thinking.

• She generates hypotheses.

• She reasons about possible explanations.

• She controls variables systematically.

• She predicts outcomes before carrying out the investigation.

• Her thinking is not limited to immediate appearance.

How thinking changes across the stages

From physical action to mental representation

In the sensorimotor stage, knowledge is based mainly on action and sensation.

By the pre-operational stage, the child can mentally represent:

• Objects.

• People.

• Events.

• Roles.

This allows language and pretend play.

From appearance to logic

Pre-operational children are strongly influenced by how things look.

Concrete operational children can use:

• Decentration.

• Reversibility.

• Classification.

They understand that appearance may change while underlying quantity remains constant.

From one perspective to several perspectives

Egocentric children struggle to separate their viewpoint from another person’s.

With development, children become more able to:

• Represent different visual viewpoints.

• Understand that people possess different information.

• Consider several perspectives.

These abilities provide a foundation for later perspective-taking and social understanding.

From concrete to abstract reasoning

Concrete operational children reason logically about familiar, tangible information.

Formal operational thinkers can reason about:

• Abstract concepts.

• Hypothetical events.

• Logical possibilities.

• Scientific theories.

From trial and error to systematic investigation

Young children may solve problems by repeatedly trying different actions.

Formal operational thinkers can:

• Plan before acting.

• Generate hypotheses.

• Isolate variables.

• Test possibilities systematically.

Developmental progression table

Cognitive feature	Sensorimotor	Pre-operational	Concrete operational	Formal operational
Main basis of thought	Sensation and action	Symbols and appearances	Logic applied to concrete information	Abstract and hypothetical logic
Mental representation	Developing	Established	More organised	Highly flexible
Object permanence	Develops	Present	Present	Present
Egocentrism	Very high	Still evident	Reduced	Further perspective possible
Conservation	Not applicable in early form	Usually absent	Present	Present
Class inclusion	Not established	Difficult	Present	Present
Abstract reasoning	Absent	Very limited	Limited	Developed
Systematic hypothesis testing	Absent	Absent	Limited	Developed

Applying the stages to the same problem

Consider four children investigating why a toy car moves farther down one ramp than another.

Sensorimotor child

The child:

• Pushes the cars repeatedly.

• Watches and listens.

• Learns through direct action.

• Repeats movements producing interesting outcomes.

Pre-operational child

The child may say:

“This ramp is better because it is red.”

The judgement may be based on a noticeable but irrelevant feature.

Concrete operational child

The child may compare:

• The height of each ramp.

• The distance travelled.

• The surface of the ramp.

Reasoning is logical when the ramps are physically present.

Formal operational child

The child may:

• Generate several hypotheses.

• Control ramp height while changing surface.

• Predict outcomes.

• Record results systematically.

• Form a general explanation.

The example shows a change in the organisation of thought, not simply an increase in factual knowledge.

The relationship between stages and schemas

Each stage is associated with increasingly complex schemas.

Sensorimotor schemas

These are mainly action based:

• Sucking.

• Grasping.

• Reaching.

• Shaking.

Pre-operational schemas

These include symbolic representations:

• Words.

• Images.

• Pretend roles.

• Simple categories.

Concrete operational schemas

These include logical relationships involving:

• Quantity.

• Classification.

• Ordering.

• Reversibility.

Formal operational schemas

These include:

• Abstract concepts.

• Hypotheses.

• Logical propositions.

• Systematic strategies.

Movement through the stages occurs as children accommodate and reorganise their schemas through equilibration.

The underlying processes are covered in how schemas change through cognitive conflict.

Evaluating Piaget’s stage-based account

Strength: it identified qualitative changes in thought

Piaget demonstrated that children do not merely possess fewer facts than adults.

Their reasoning may be organised differently.

For example:

• A young child uses height to judge liquid quantity.

• An older child considers height, width and reversibility.

• An adolescent can reason about hypothetical systems.

This was an important contribution because it encouraged psychologists to investigate children’s explanations and errors rather than measuring only correct answers.

Strength: the stages organise a wide range of abilities

The theory connects several developments within one framework.

These include:

• Object permanence.

• Symbolic thought.

• Egocentrism.

• Conservation.

• Classification.

• Abstract reasoning.

The stage structure provides a clear overview of how cognition may become more advanced.

This makes the theory useful for:

• Organising research.

• Generating predictions.

• Comparing age groups.

• Planning developmentally suitable activities.

Strength: carefully documented procedures encouraged replication

Piaget developed recognisable tasks involving:

• Hidden objects.

• Changes in liquid containers.

• Rows of counters.

• Visual perspectives.

• Classification.

AQA’s 2023 mark scheme recognises the innovative, well-documented and replicable nature of Piaget’s procedures as a strength of his research.

Other psychologists have been able to:

• Repeat the procedures.

• Modify the instructions.

• Compare age groups.

• Test alternative explanations.

This has produced a large body of developmental research.

Strength: educational applications

Piaget’s theory has influenced education by encouraging:

• Active learning.

• Discovery.

• Practical materials.

• Tasks suited to cognitive development.

• Opportunities to correct misconceptions.

For example:

• Younger pupils may benefit from physical objects when learning mathematics.

• Conservation may be developed through water play and measuring containers.

• Abstract explanations may be introduced after concrete examples.

AQA mark schemes recognise the educational importance of specialist play materials and active exploration.

Limitation: Piaget may have underestimated infant abilities

Piaget concluded that object permanence develops at approximately eight to nine months.

Baillargeon’s violation-of-expectation research suggests that infants as young as two to three months may possess some knowledge of hidden objects.

Infants looked longer at apparently impossible events, such as an object seeming to disappear or a screen appearing to move through a hidden block.

This challenges the sensorimotor timetable.

AQA’s 2025 mark scheme explicitly recognises Baillargeon’s evidence as suggesting that object permanence emerges earlier than Piaget proposed.

Performance may not equal understanding

Piaget often measured object permanence by whether an infant physically searched for a hidden object.

Failure to search might result from:

• Limited reaching ability.

• Poor coordination.

• Lack of motivation.

• Forgetting the exact location.

• Difficulty planning the action.

The infant may possess some understanding while being unable to demonstrate it through movement.

Piaget may therefore have confused:

• Competence, what the child understands.

• Performance, what the child can show in a particular task.

Limitation: conservation may appear earlier with child-friendly methods

In Piaget’s conservation tasks, children were often asked about quantity:

1. Before a transformation.

2. Again after the transformation.

A child might interpret the repeated question as a signal that the first answer was incorrect.

McGarrigle and Donaldson changed the procedure so that a “naughty teddy” accidentally altered the arrangement.

Children under seven were more likely to conserve when the transformation appeared accidental.

This suggests that younger children’s failure may reflect:

• The wording of the task.

• The social situation.

• The apparent intention of the adult.

rather than a complete absence of logical understanding.

AQA’s 2023 mark scheme identifies repeated questioning and McGarrigle and Donaldson’s child-friendly procedure as evidence that conservation may develop earlier than Piaget claimed.

Limitation: task demands may affect stage classification

A child may fail because:

• Instructions are complex.

• The materials are unfamiliar.

• The researcher repeats a question.

• The child misunderstands the purpose.

• The response requires language or motor skills.

The child may therefore appear to be in an earlier stage than their actual cognitive competence suggests.

This weakens claims that success or failure on one task reveals a general stage of intellectual development.

Limitation: stages may be too rigid

Piaget’s theory suggests broad and coherent changes in thinking.

In practice, a child may demonstrate advanced reasoning in one area but not another.

For example, a child might:

• Conserve number but not volume.

• Understand one class-inclusion problem but fail a less familiar version.

• Reason abstractly about a familiar hobby but concretely in another subject.

Development may therefore be more gradual and uneven than a strict stage theory implies.

The child may not switch from one complete form of thought to another all at once.

Limitation: ages should not be treated as universal deadlines

Children differ in:

• Experience.

• Education.

• Language.

• Culture.

• Familiarity with tasks.

• Opportunities for exploration.

These factors may influence when particular abilities are demonstrated.

The stage order may provide a useful broad pattern, while the exact ages vary considerably.

Limitation: social interaction is underemphasised

Piaget emphasised the child as an independent explorer or young scientist.

He gave less attention to guidance from:

• Parents.

• Teachers.

• Siblings.

• Peers.

• Wider culture.

Vygotsky’s social explanation of cognitive development argues that children can achieve more when supported by a more knowledgeable person.

A child may reach a solution through:

• Demonstration.

• Prompting.

• Questioning.

• Scaffolding.

• Dialogue.

This suggests that intellectual development cannot be explained solely through individual maturation and independent exploration.

Limitation: formal operational thought may depend on experience

Abstract and scientific reasoning may not appear equally in every person or every situation.

Performance may depend on:

• Education.

• Familiarity.

• Subject knowledge.

• Motivation.

• Whether the problem has personal meaning.

Someone may reason formally in an area of expertise but use concrete reasoning in an unfamiliar context.

Formal operational thought may therefore be an ability that develops and is applied unevenly, rather than an automatic universal stage reached in the same form by everyone.

Limitation: stage explanations can become maturationist

A strong stage account may imply that children must wait until they are biologically ready before advanced learning can occur.

This could lead teachers to:

• Delay useful instruction.

• Underestimate pupils.

• Treat age as more important than experience.

• Assume failure proves lack of readiness.

Evidence that support and task design improve performance suggests that development is not controlled by maturation alone.

Limitation: Piaget’s original sample

Piaget’s conclusions were initially developed using a limited group of children.

A restricted sample makes it difficult to know whether:

• The stages apply identically across cultures.

• The age ranges are universal.

• Educational experience affects performance.

• Children raised in different environments use the same strategies.

Later replication has increased understanding, but the original evidence should not be treated as a fully representative basis for universal claims.

Piaget compared with Vygotsky

Piaget	Vygotsky
Development progresses through broad intellectual stages	Development is strongly shaped by social interaction
Child is an active scientist	Child is an apprentice
Independent exploration is central	Guidance from more knowledgeable others is central
Maturation helps determine readiness	Learning can lead development
Stages are broadly universal	Cognitive skills reflect cultural tools and experience
Teacher provides suitable discovery activities	Teacher provides scaffolding within the ZPD

The theories are not completely incompatible.

A child may:

• Explore actively, as Piaget proposed.

• Receive carefully adjusted guidance, as Vygotsky proposed.

A combined account recognises both independent construction and social support.

Evaluating the theory as a whole

Does the evidence reject stages completely?

Evidence that children succeed earlier than Piaget predicted does not mean intellectual development shows no pattern.

Older children generally demonstrate more advanced:

• Conservation.

• Classification.

• Perspective-taking.

• Abstract reasoning.

The main challenge concerns whether development occurs through:

• Four sharply separated stages.

• At the exact ages Piaget proposed.

• In the same way across every task and culture.

A balanced conclusion

Piaget’s theory remains valuable as a broad account of intellectual progression.

It captures an important developmental shift:

action-based thinking → symbolic thought → concrete logic → abstract reasoning

However, the stages are more convincing as approximate descriptions than as a rigid timetable.

Children’s performance is influenced by:

• Task demands.

• Language.

• Motor ability.

• Familiarity.

• Education.

• Social support.

• Culture.

Development is therefore likely to be structured but more gradual, variable and socially influenced than a strict interpretation of Piaget’s stages suggests.

Applying the stages in examinations

Step 1: Identify the child’s age

Age provides a clue, but it should not be the only evidence used.

Step 2: Identify the cognitive behaviour

Look for:

• Physical exploration.

• Search for hidden objects.

• Symbolic or pretend play.

• Egocentrism.

• Failure or success in conservation.

• Class inclusion.

• Abstract hypothesis testing.

Step 3: Name the stage

State the relevant stage explicitly.

Step 4: Explain the mechanism

Do not stop after naming the stage.

Explain why the behaviour demonstrates that type of thinking.

Step 5: Use contrasting abilities where helpful

For example:

“Luca can conserve number, showing concrete operational thought. However, the problem does not require abstract hypothetical reasoning, so it does not demonstrate formal operations.”

Application structure

Use:

scenario detail → cognitive characteristic → explanation → stage

For example:

“Zara searches beneath the blanket for the toy, demonstrating object permanence because she understands that it continues to exist when hidden. This ability develops during the sensorimotor stage.”

Hints from the Examiner Reports 💡

Examiner hint: Keep the answer focused on the stage named in the question. In 2025, some students discussed concepts from later stages when the question asked specifically about

sensorimotor development.

Examiner hint: Use age as supporting evidence, not as your entire application. Saying “the child is eight, so they are concrete operational” is weaker than identifying conservation, class inclusion or reversible reasoning.

Examiner hint: Make explicit links to every useful detail in a scenario. The 2025 examiner report praised answers that connected object permanence and schema development directly to the two infants described.

Examiner hint: Distinguish the stages using their characteristic forms of thinking:

• Sensorimotor: action and sensation.

• Pre-operational: symbolic but appearance based.

• Concrete operational: logical with concrete information.

• Formal operational: abstract and hypothetical.

Examiner hint: Do not claim that conservation develops during the pre-operational stage. The child generally fails conservation during that stage and succeeds during concrete operations.

Examiner hint: Evaluation must address the stage account. A general criticism of Piaget gains value when you explain which prediction it challenges.

Examiner hint: When using Baillargeon, explain that earlier evidence of object permanence challenges Piaget’s sensorimotor timetable.

Examiner hint: When using McGarrigle and Donaldson, explain that child-friendly procedures allowed younger children to conserve, suggesting Piaget’s task underestimated competence.

Examiner hint: Avoid generic methodological statements. Explain exactly how repeated questions, motor demands or unfamiliar materials could make a child appear less cognitively advanced.

Examiner hint: For a “discuss” question, balance knowledge and evaluation. Do not spend the entire answer describing the four stages before adding one sentence of criticism.

Common Mistakes ⚠️

Mistake: Placing the stages in the wrong order

Why this is incorrect:

Piaget proposed a fixed developmental sequence.

How to improve:

Use:

senses and actions → symbols → concrete logic → abstract logic

Mistake: Treating the ages as exact boundaries

Why this is incorrect:

The age ranges are approximate, and performance varies between children and tasks.

How to improve:

Use phrases such as “approximately” and identify the demonstrated ability.

Mistake: Saying object permanence develops in the pre-operational stage

Why this is incorrect:

Piaget placed its development within the sensorimotor stage.

How to improve:

Link hidden-object searching with later sensorimotor development.

Mistake: Calling all repeated infant behaviour reflexive

Why this is incorrect:

Later repetition may be intentional and based on learned consequences.

How to improve:

Distinguish early reflexes from circular reactions and goal-directed behaviour.

Mistake: Saying pre-operational children cannot think

Why this is incorrect:

They can use language, symbols and imagination.

How to improve:

State that their thinking is not yet consistently logical and remains influenced by appearance.

Mistake: Defining egocentrism as selfishness

Why this is incorrect:

Piagetian egocentrism concerns difficulty representing another viewpoint.

How to improve:

Use a perspective-taking example rather than a moral judgement.

Mistake: Saying centration means poor concentration

Why this is incorrect:

Centration means focusing on one dimension of a problem.

How to improve:

Apply it to height in a conservation-of-volume task.

Mistake: Saying conservation means protecting resources

Why this is incorrect:

In Piaget’s theory, conservation concerns understanding that quantity stays constant despite appearance changes.

How to improve:

Refer to number, mass or volume.

Mistake: Saying concrete operational children can reason abstractly

Why this is inaccurate:

Their logical reasoning is strongest when information is concrete, familiar or physically represented.

How to improve:

Reserve abstract and hypothetical reasoning for formal operations.

Mistake: Saying formal operational thinking is simply being more intelligent

Why this is incomplete:

Piaget described a particular form of abstract, hypothetical and systematic reasoning.

How to improve:

Apply hypothesis generation or controlled testing.

Mistake: Naming a stage without explaining the evidence

Why this is incomplete:

Application marks require use of the scenario.

How to improve:

Quote or paraphrase the relevant behaviour and link it to a characteristic.

Mistake: Treating one failed task as proof of a complete stage

Why this is incorrect:

Language, attention, motivation and task demands may affect performance.

How to improve:

Use several pieces of evidence and acknowledge alternative explanations.

Mistake: Saying later evidence completely disproves Piaget

Why this is too strong:

Later studies often challenge the ages or methods rather than the entire pattern of cognitive development.

How to improve:

Conclude that development may be earlier, more gradual or more task dependent than Piaget proposed.

Exam-Style Questions ✍️

Questions

1. Name Piaget’s four stages of intellectual development in the correct order.[4 marks]

2. Outline two characteristics of the sensorimotor stage.[4 marks]

3. Explain one difference between pre-operational and concrete operational thinking.[4 marks]

4. Four-year-old Amira says that there are more counters after one row is spread out.

Explain Amira’s answer using Piaget’s stages of intellectual development.[4 marks]

5. Eight-year-old Daniel says that the number of counters remains the same because none have been added or removed.

Explain Daniel’s answer using Piaget’s theory.[4 marks]

6. Eleven-year-old Seren is asked why plants grow at different rates. Seren suggests four possible explanations and designs a different investigation for each one.

Explain which stage Seren’s behaviour demonstrates.[4 marks]

7. A researcher tests object permanence by hiding a toy and recording whether infants reach for it.

Explain one reason why this method might underestimate infants’ cognitive development.[3 marks]

8. A researcher tests conservation using two procedures.

Procedure	Percentage of 6-year-olds giving a conserving answer
Adult deliberately changes the arrangement and repeats the question	38
A toy accidentally changes the arrangement	71

a) Calculate the difference between the percentages.[1 mark]

b) Explain what the results suggest about Piaget’s stage theory.[3 marks]

9. Explain one strength and one limitation of Piaget’s stage-based account of intellectual development.[6 marks]

10. Compare the sensorimotor and pre-operational stages of intellectual development.[6 marks]

11. Discuss Piaget’s stages of intellectual development.[16 marks]

Answers and Mark Scheme

Question 1

Award one mark for each stage in the correct order:

1. Sensorimotor.

2. Pre-operational.

3. Concrete operational.

4. Formal operational.

Question 2

Award up to two marks for each outlined characteristic.

Possible content:

• Knowledge is initially based on sensation and physical action.

• Early behaviour includes reflexes such as sucking and grasping.

• Infants learn through repeated actions and trial and error.

• Behaviour becomes increasingly intentional.

• Object permanence develops.

• Mental representation or symbolic function begins.

• Infants are highly egocentric.

Question 3

Award up to four marks:

• Pre-operational thinking is symbolic but strongly influenced by appearances.

• Children may show egocentrism, centration and failure of conservation.

• Concrete operational thinking involves logical operations applied to concrete information.

• Children can decentre, reverse transformations, conserve and understand class inclusion.

Credit an accurate comparative example.

Question 4

Award up to four marks:

• Amira is within the approximate age range of the pre-operational stage.

• She is influenced by the longer appearance of the spread-out row.

• She shows centration by focusing on row length.

• She fails conservation of number.

• She does not use reversibility or recognise that nothing was added or removed.

Age alone should not receive full credit without application to her reasoning.

Question 5

Award up to four marks:

• Daniel demonstrates concrete operational thinking.

• He understands conservation of number.

• He recognises identity because the same counters remain present.

• He can consider the transformation logically rather than relying on appearance.

• His explanation suggests decentration or reversibility.

Question 6

Award up to four marks:

• Seren demonstrates formal operational thinking.

• She generates several hypotheses.

• She reasons about possible rather than only visible explanations.

• She designs systematic tests for each hypothesis.

• This is consistent with hypothetico-deductive reasoning.

Question 7

Award up to three marks:

• Reaching requires motor coordination and planning.

• An infant may understand that the toy continues to exist but lack the ability or motivation to retrieve it.

• Failure to reach may therefore measure performance rather than object-permanence competence.

• Piaget could consequently place the infant in an earlier stage than their understanding justifies.

Question 8a

One mark for:

71−38=33

The difference is 33 percentage points.

Question 8b

Award up to three marks:

• More children conserved when the change appeared accidental.

• Performance is therefore affected by the social wording or procedure of the task.

• Piaget’s original method may have underestimated the competence of children under seven.

• The age boundary between pre-operational and concrete operational reasoning may be less rigid than proposed.

Do not claim the difference is statistically significant because no inferential-test result is provided.

Question 9

Award up to three marks for a developed strength and three for a developed limitation.

Possible strength:

Piaget identified meaningful qualitative differences between children’s thinking. The stages organise developments such as object permanence, conservation and abstract reasoning and have informed developmentally appropriate educational practice.

Possible limitation:

Modified tasks show that children may possess abilities earlier than Piaget proposed. Baillargeon found evidence suggesting earlier object permanence, while child-friendly conservation tasks reduce young children’s errors. This suggests that Piaget sometimes measured task performance rather than underlying competence.

Alternative creditworthy points include:

• Replicable and influential procedures.

• Active-learning applications.

• Stages may be too rigid.

• Social and cultural influences are underemphasised.

• Original samples were limited.

• Formal reasoning depends on experience and familiarity.

Question 10

Award up to six marks for direct comparison.

Possible content:

• Both are early stages in Piaget’s fixed sequence.

• Sensorimotor development occurs from birth to approximately two, whereas pre-operational development occurs from approximately two to seven.

• Sensorimotor knowledge is based primarily on senses and physical action.

• Pre-operational children use language, images and other symbols.

• Object permanence develops in the sensorimotor stage and is present during pre-operations.

• Symbolic function begins near the end of sensorimotor development and becomes central in pre-operational thought.

• Both stages involve egocentric thinking.

• Pre-operational children can mentally represent absent objects but remain limited by centration and lack of conservation.

• Sensorimotor children learn mainly through physical trial and error, whereas pre-operational children can engage in pretend play.

Higher marks require linked comparisons rather than two independent descriptions.

Question 11

A strong response should include:

Knowledge and understanding

• Piaget’s theory as a stage-based account.

• The fixed sequence and qualitative nature of development.

• Sensorimotor stage from birth to approximately two.

• Sensory and motor schemas.

• Reflexes, circular reactions and trial and error.

• Intentional behaviour.

• Object permanence.

• Early symbolic function.

• Pre-operational stage from approximately two to seven.

• Language and symbolic thought.

• Egocentrism.

• Centration and lack of conservation.

• Concrete operational stage from approximately seven to eleven.

• Decentration.

• Reversibility.

• Conservation.

• Class inclusion and classification.

• Formal operational stage from approximately eleven.

• Abstract and hypothetical reasoning.

• Systematic hypothesis testing.

• Movement from physical action to symbolic, concrete logical and abstract thought.

Evaluation

• The theory identifies qualitative changes in thinking.

• The stages organise a wide range of developmental findings.

• Piaget’s tasks were innovative and stimulated extensive replication.

• Educational applications involving discovery and concrete materials.

• Baillargeon suggests object permanence appears earlier.

• Motor demands may confuse performance with competence.

• McGarrigle and Donaldson suggest conservation can appear before seven.

• Repeated questioning and unfamiliar materials affect task performance.

• Stages may be too rigid or discontinuous.

• Children may demonstrate different levels in different domains.

• Exact ages may vary with culture, education and experience.

• Piaget underemphasises social interaction and scaffolding.

• Formal operational reasoning may depend on familiarity and education.

• Original samples limit universal conclusions.

• The broad developmental sequence may remain valuable despite problems with timing and rigidity.

Higher-level responses will cover all four stages accurately and use evidence to evaluate the stage-based account, rather than offering disconnected criticisms of individual tasks.