Piaget’s theory of cognitive development: schemas, assimilation,…

The idea

A schema is a mental packet of knowledge. Piaget argued children build them: experience fitting an existing schema is assimilated, clashing experience creates disequilibrium requiring accommodation, and equilibration drives the return to balance. Four stages of intellectual development follow: sensorimotor (object permanence at eight months), pre-operational (egocentrism, failure of conservation, failure of class inclusion), concrete operational, and formal operational. Evaluation is key: Hughes (1975) found 90% of young children could hide a doll from policemen, and McGarrigle and Donaldson (1974) raised conservation success from 16% to 62.5% when a naughty teddy made the change look accidental, showing Piaget understated early abilities.

What earns the marks

• Schema defined as a mental framework or packet of knowledge used to organise and interpret experience, constructed by the child rather than taught.
• Assimilation: new information is taken into an existing schema, which does not have to change.
• Accommodation: information that will not fit produces disequilibrium, so a schema is altered or a new one formed; equilibration is the return to a balanced state and is the motor of development.
• Named evidence: the blanket and hidden toy, the three mountains task, the counters and beakers conservation tasks, and the dogs-and-animals class inclusion question.

Common mistakes and how to put them right

• Swapping assimilation and accommodation, or calling any new learning accommodation when nothing about the schema actually changed.

• Attaching a characteristic to the wrong stage, most often putting object permanence in the pre-operational stage or conservation in the sensorimotor stage.

• Explaining egocentrism as selfishness rather than an inability to represent another person’s viewpoint.

• Listing the four stages with ages and stopping there, which caps an essay at the descriptive marks and throws away the larger evaluation allocation.

• Saying the studies "prove Piaget wrong" when what they show is that his tasks made the competence look later than it is.

Exam tips

• When writing an extended essay, describe two or three stage features precisely and then spend most of the answer on the counter-evidence and on Vygotsky to ensure sufficient evaluation.
• In a scenario question, name the stage and quote the behaviour in the stem that shows it; the application mark is for the link, not for the label.
• If the question says outline, give the mechanism and no evaluation; if it says apply, every point must be anchored to the child described.
• Quote the finding, not just the researcher: the percentage from Hughes or from the naughty teddy study is what turns a vague criticism into a credited one.