4.3.4 - Piaget's theory of cognitive development

Schemas and adaptation

Piaget argued that children are not just smaller adults who know fewer facts. They think in qualitatively different ways as they develop. His theory is a constructivist account: children actively build knowledge through exploring the world, testing their understanding and changing their mental structures.

For Piaget, babies begin with simple action-based schemas, such as sucking and grasping. Over time, schemas become more complex. A toddler's early "dog" schema may include "four legs, fur, barks"; later it may split into pets, farm animals, breeds and wild animals.

If a child who knows about Labradors sees a spaniel and calls it a dog, they are using assimilation. The spaniel is new, but it fits the existing "dog" schema.

If the same child sees a cat and calls it a dog, then notices that it meows, climbs and behaves differently, they may form a separate "cat" schema. That is accommodation.

When an existing schema cannot account for an experience, the resulting disequilibrium motivates accommodation. Assimilation handles experiences that can already be interpreted within a schema; accommodation changes the framework. Equilibration describes the regulation of this balance, rather than a separate fact learnt by the child.

Piaget's learning cycle is:

A useful distinction is between changing the example and changing the framework. A child can even assimilate incorrectly: calling a zebra a horse may fit the child's existing horse schema. Accommodation occurs when the child changes that schema, for example distinguishing horses from zebras. A correct label alone does not tell us which process occurred; we need to know whether the child's understanding changed.

The stage model

Piaget proposed four stages of intellectual development. In his account the sequence is invariant: the stages occur in the same order. The age ranges below are approximate expectations within the theory, not deadlines or a way to diagnose a child from their birthday.

The stage model is domain-general: Piaget thought a child's reasoning changes broadly across many areas at once. For example, a pre-operational child should show limitations in conservation, perspective-taking and class inclusion because the underlying logical structure is not yet developed.

Sensorimotor thinking and object permanence

During the sensorimotor stage, infants learn by coordinating sensations and actions. They look, grasp, suck, reach, drop and repeat actions to discover what happens.

Piaget observed that very young babies often stop searching when an object is hidden. Later in infancy, they begin to search under a cloth or behind a screen. Piaget interpreted this as evidence that the child now represents the object mentally: the toy still exists even though it is out of sight.

For example, an infant accidentally hits a hanging rattle and hears a sound. Repeating the movement lets the infant connect an action with its effect; later, deliberately pulling a cloth to bring a toy nearer shows more organised, goal-directed action. Towards the end of the stage, mental representation and simple symbolic play become possible, such as using a block as a pretend phone. These changes make the stage more than simply a test of searching.

Piaget associated the beginnings of successful hidden-object search with about eight months, with understanding developing further during infancy. If a younger infant stops reaching when a rattle is covered, Piaget would interpret this as object permanence not yet being secure. If an older infant lifts the cloth to find it, that is positive evidence of representing the hidden rattle. The inference is asymmetric: successful search supports understanding, but failed search could also reflect poor coordination, attention or memory. Baillargeon's looking-time research, taught later in this option, tests that alternative.

Pre-operational limitations

The pre-operational stage is important for AQA because it contains three named characteristics: egocentrism, conservation and class inclusion. The child can use words and mental symbols, but on Piagetian tasks their reasoning may centre on one striking feature. Centration means focusing on one aspect at the expense of others; decentring means coordinating more than one aspect. Egocentrism here concerns difficulty coordinating viewpoints; it does not mean selfishness.

Piaget and Inhelder (1956) tested egocentrism using the Three Mountains Task. Children saw a model of three mountains with distinctive features, such as snow, a cross or a house. A doll was placed in a different position from the child. The child then had to choose the picture showing what the doll could see. Many pre-operational children chose the picture matching their own view rather than the doll's view. Piaget and Inhelder concluded that young children found it difficult to decentre from their own perspective.

In a liquid conservation task, a child first sees two identical glasses containing the same amount of liquid. When one glass is poured into a taller, thinner glass, a pre-operational child may say the taller glass has more because they focus on height. In a number conservation task, they may say a spread-out row of counters has more counters than a shorter row with the same number.

Failure of conservation often shows lack of reversibility. The child does not mentally pour the liquid back or push the counters back together.

Piaget and Inhelder (1964) used class-inclusion questions such as showing children five dogs and two cats, then asking whether there are more dogs or more animals. A pre-operational child may answer "more dogs" because they focus on the visible subcategory and fail to treat dogs and cats together as animals.

Consider seven flowers: five red and two yellow. The class-inclusion comparison is five red flowers versus all seven flowers, not five red versus two yellow. A child who answers “more red flowers” may be comparing the two subclasses and missing the relationship between a part and the whole. Counting to seven correctly is therefore not sufficient evidence of class inclusion.

In an application, identify the reasoning the child shows, then link it to the theory. Age can support that interpretation, but the decisive detail is the child's explanation. A five-year-old who conserves on a suitable task should receive credit for that demonstrated reasoning rather than being declared unable because of the age table.