Stages of Development by Piaget


A child’s cognitive development is about a child developing or constructing a mental model of the world.

Imagine what it would be like if you did not have a mental model of your world.  It would mean that you would not be able to make so much use of information from your past experience, or to plan future actions.

Jean Piaget was interested both in how children learnt and in how they thought.

Piaget studied children from infancy to adolescence, and carried out many of his own investigations using his three children. He used the following research methods:

Naturalistic observation: Piaget made careful, detailed observations of children. These were mainly his own children and the children of friends. From these he wrote diary descriptions charting their development.

Clinical interviews and observations of older children who were able to understand questions and hold conversations.

Piaget believed that children think differently than adults and stated they go through 4 universal stages of cognitive development.  Development is therefore biologically based and changes as the child matures.  Cognition therefore develops in all children in the same sequence of stages.

Each child goes through the stages in the same order, and no stage can be missed out – although some individuals may never attain the later stages. There are individual differences in the rate at which children progress through stages.

Piaget did not claim that a particular stage was reached at a certain age – although descriptions of the stages often include an indication of the age at which the average child would reach each stage.

Piaget (1952) believed that these stages are universal – i.e. that the same sequence of development occurs in children all over the world, whatever their culture.

Stage of Development Key Feature Research Study
0 – 2 yrs.
Object Permanence Blanket & Ball Study
2 – 7 yrs.
Egocentrism Three Mountains
Concrete Operational
7 – 11 yrs.
Conservation Conservation of Number
Formal Operational
11yrs +
Manipulate ideas in head, e.g. Abstract Reasoning Pendulum Task

Stages of Cognitive Development

Stage  Characterised by 
(Birth-2 yrs) 
Differentiates self from objects Recognises self as agent of action and begins to act intentionally: e.g. pulls a string to set mobile in motion or shakes a rattle to make a noise 

Achieves object permanence: realises that things continue to exist even when no longer present to the sense (pace Bishop Berkeley) 

(2-7 years) 
Learns to use language and to represent objects by images and words Thinking is still egocentric: has difficulty taking the viewpoint of others 

Classifies objects by a single feature: e.g. groups together all the red blocks regardless of shape or all the square blocks regardless of colour 

Concrete operational
(7-11 years) 
Can think logically about objects and events Achieves conservation of number (age 6), mass (age 7), and weight (age 9) 

Classifies objects according to several features and can order them in series along a single dimension such as size. 

Formal operational
(11 years and up) 
Can think logically about abstract propositions and test hypotheses systemtically Becomes concerned with the hypothetical, the future, and ideological problems 

Read more: Piaget’s developmental theory
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