Piaget's Stages of Intellectual Development (AQA A Level Psychology): Revision Note

The sensorimotor stage

• The sensorimotor stage spans the ages from birth to around 2 years old and is marked by the child’s body schema and the physical exploration of their environment 

• Young children in this stage learn via a set of physical schemas, e.g., sucking schema, trajectory schema, which are not reflexes

  • They are performed intentionally as the child derives pleasure from them (this explains why a baby might hurl their dish from their highchair and then laugh uproariously)

• A key marker of this stage of cognitive development is when a baby acquires object permanence, usually around the age of 8 months

• Object permanence can be tested using the ‘A-not-B’ task

  • This involves hiding a toy under location A in front of the child several times in a row and asking the child to retrieve the toy

  • The toy is then hidden under location B, and if the child continues to look for the toy under location A, they have failed the task (i.e., they have not acquired object permanence)

• Passing the ‘A-not-B’ task shows that the child understands that the toy still exists even though it cannot be seen, and their initially reinforced (via several trials) movement to retrieve it from location A can be overridden by their new knowledge that the toy is now in location B

The pre-operational stage

• The pre-operational stage is probably the most-researched of all four of Piaget’s stages, as children show the most developmental milestones in this stage, and they are more receptive to taking part in research compared to babies

• This stage spans the ages of 2-7 years old and is characterised by the development of increasingly sophisticated schemas, pretend play, anthropomorphism, an understanding of time and the ability to de-centre

• Key markers of this stage comprise:

  1. Egocentrism –  lacking the ability to see the world from another’s perspective (passing an egocentrism task marks the end of this stage)

  2. Conservation – lacking the ability to appreciate that objects or materials remain the same even when their appearance changes (passing a conservation task marks the end of this stage)

  3. Class inclusion – lacking the ability to classify objects into two or more categories

Conservation

• Piaget tested conservation using experimental methodology as follows:

  1. Present equal quantities
     Show the child two equal amounts of material side by side (e.g., liquid in identical glasses, equal clay balls, or equal rows of coins)

  2. Initial question
     Ask: “Does this one have more, does that one have more, or are they the same?”

  3. Transform one item
     While the child watches, alter the appearance of one material (e.g., pour liquid into a taller container, flatten one clay ball, spread out one row of coins)

  4. Repeat the question
     Ask the same question again: “Does this one have more, does that one have more, or are they the same?”

  5. Evaluate the response

     • If the child says one now has more/less: Fail – they focus on appearance, not logic

     • If the child says they’re still the same: Pass – they understand conservation

• The conservation task tests a key developmental milestone in children, as to pass it, the child must be able to perform a reverse operation, i.e., by ‘conserving’ the idea that both materials are the same in terms of capacity so that they can go back (in their head) and see them as the same even when the transformed appearance of one of them makes them look as if they have different capacities

Egocentrism

• Piaget & Inhelder (1956) tested egocentrism via a test known as the 3 Mountains Task, which runs as follows:

  1. Present the model
     Show the child a 3D model landscape with three mountains and features like animals or trees

  2. Introduce the doll
     Place a doll on the opposite side of the model, facing the landscape from a different viewpoint than the child

  3. Ask the perspective question
     Ask the child: “What does the doll see?”
     The child selects a picture from several images showing the model from different angles

  4. Observe the response

     • Young children (around 4 years old) typically choose the image that matches their own view – showing egocentrism

     • By age 7–8, children more consistently select the doll’s viewpoint – showing reduced egocentrism and improved perspective-taking

• The 3 Mountains Task tests a key developmental milestone because to pass it, the child must be able to decentre, which shows more maturity and sophisticated thinking

Class inclusion

• Piaget tested class inclusion as follows:

  1. Present the Set
     Show the child a picture or model of a set of items, e.g., a bunch of flowers

  2. Identify Subclasses
     The set includes two subgroups — for example, five daffodils and three poppies

  3. Ask the Inclusion Question
     Ask the child: “Are there more daffodils or more flowers?”

  4. Evaluate the Response

     • If the child answers “more daffodils”, they fail the class inclusion task, showing they do not yet understand that “flowers” includes both daffodils and poppies

     • If the child answers “more flowers”, they pass, demonstrating an understanding of hierarchical categorisation

• The class inclusion task tests a key developmental milestone in children, as to pass it, the child must be able to understand that ‘daffodils’ are a subcategory of the overarching category of ‘flowers’

The concrete operational & the formal operational stages

• The concrete operational stage spans the ages 7-11 years and is marked by an understanding of:

  • the conservation of volume, mass and number

  • the ability to de-centre

  • the ability to classify and categorise objects more accurately

• Children in this stage can perform mental operations that require logic, e.g., mathematics, up to a certain point, but they may lack a systematic approach to problem-solving

• The formal operational stage spans the ages 11+ years and is marked by increasingly systematic and sophisticated mental operations, abstract thought, relativism and the ability to debate and manipulate ideas and principles

Research which investigates Piaget’s stages of intellectual development

• Samuel & Bryant (1984) found that by asking 4-8 year-old children only one question in total (after viewing the transformation of volume/mass/number)

  • Those children made fewer mistakes, even those aged 4 years old thus, Piaget’s stages are not as inflexible as he suggested

• Piaget & Inhelder (1956) - The original 3 Mountains study as described above

• Hughes (1975) found that fewer children aged 3 to 5 years old fail a test of egocentrism if the procedure changes to include two policeman dolls that a boy doll has to hide from using four interlocking walls, i.e., the children could understand that if the boy stood at point X, then the policemen could not see him

• McGarrigle (1974) changed the wording of a standard Piagetian class inclusion task by asking pre-operational children if there were ‘more black cows or more sleeping cows?’ (the standard question was, ‘more black cows or more cows?’)

  • The cows were placed lying down, they appeared to be sleeping and this resulted in 48% of the children passing the test as opposed to 25% passing the standard Piagetian version

Evaluation of Piaget’s stages of intellectual development

Strengths

• Piaget’s stage theory has great application to educational settings, as it sets out the benchmarks for educators and health professionals to use to assess progress and flag any developmental delays that a child may be experiencing

• Piaget's stage theory changed the way that researchers think about children, i.e., children are not simply smaller versions of adults

  • The way children think is fundamentally different from the way that adults think

Limitations

• Children do not develop synchronistically, achieving key milestones at the same time, which means that the theory lacks reliability, as it is unlikely to show consistency across age groups and particularly across cultures

• Piaget’s original research has had to be modified over the years, as the procedures can themselves constitute confounding variables, e.g., how many children (or even adults)  are able to describe a mountainous landscape with ease if they have grown up in a non-mountainous region?

Issues & Debates

• Piaget’s theory uses a nomothetic approach, applying universal developmental stages to all children, based on broad patterns of thinking

  • This ignores individual differences in cognitive development, such as personal experiences, language ability, and cultural background, which are better explained through idiographic approaches

• Piaget’s tasks (e.g., the 3 Mountains task) rely on Western cultural knowledge, such as familiarity with mountainous landscapes, which may disadvantage children from non-Western or rural backgrounds

  • Studies like Dasen (1994) show that cognitive abilities develop differently across cultures, challenging the universality of Piaget’s stages