Piaget: Stages of Cognitive Development

Jean Piaget, the Swiss biological epistemologist, who worked on cognitive development in humans, has divided cognitive development into four stages:

1. Sensori-Motor (0-2)

2. Pre Operational (2-7)

3. Concrete Operational (7-11)

4. Formal Operational (11-14)

Sensori Motor Stage(0-2)

The most significant achievement in this stage of life is object permanence. An infant does not have a developed memory, and due to this reason things’ impression on an infant’s mind does not last for long. Thus when an infant watches an attractive colorful thing for example, he goes for it and wants to grab it. However, if that object is removed from the sight of the infant, he no longer searches for it. From this observation Piaget concludes that infants do not have a well defined memory, for had they possess a well defined memory they would have remembered that object and tried to search for it.

However by the age of 11 months, infants develop this kind of memory and then they are able to pursue objects even if objects are removed from their sight, this shows that objects now have a relatively permanent image in their mind. This is reckoned by Piaget as a major sign of cognitive development and leads to the development of symbolic thinking and vocabulary development in later stages of life.

Once a child achieves object permanence, then he is also able to signify objects with linguistic signs, and hence becomes able to maintain a memory of things. Thus during this period of development, the best game to be played is to show and then hide an object, so that the infant tries to find it.

The other achievements in infancy include development of schemas. Piaget describes two principles of accommodation and assimilation in this regard. The sense organs for learning in the infancy are hands, mouth and eyes. An infant grasps a thing and tries to bring it to his mouth, through hand eye coordination.

When an infant holds something in hands, and carries it to the mouth, this amounts to the development of a schema, or a rough scheme to hold and grasp things and to bring them to the mouth. When a child finds a thing that fits to the scheme that is called assimilation. In case the object does not fit the established scheme, the infant changes strategy to hold it; this is called accommodation.

These schemas continue to develop in the later stage, and are not at all restricted in type to the infantile schema of holding and grasping things. Later examples of cognitive strategies or schemas are when a child solves a problem with a learned technique and is able to sole all similar problems with only slight variations, however when a problem arises that requires a change in the scheme or problem solving strategy or the schema, the child now accommodates his strategy do deal with the new situation.

Third important development in this age of infancy is the learning of cause and effect; so a child knows that tapping a bowl causes a sound.

Pre Operational Stage(2-7)

This stage starts from the age of 2 and continues till the age of 07. During this stage a child develops language, symbolic presentation of things, as in child plays when children decide to consider paper pieces as currency notes. This stage is very important for more and more learning through environment and interaction, for children in this stage do not have their critical reasoning working. They are in a make belief stage and if a story is told to them they immediately believe, they also believe anything during their games and assign symbolic roles to different things.

Children in this stage have an egocentric thinking, and they cannot imagine how others think. So a child remains egocentric, and thinks that others have experiences similar to them. A child instead of asking a stranger, do you know me? Can ask him do I know you? They can ask others what they themselves are feeling as if others know it as they know it.

Children cannot classify things into two categories simultaneously, so if you give them geometric shapes of two colors, then they can either organize them according to color or shape; they cannot separate yellow triangles and blue squares.

Children also do not have any idea of conservation issues. So if you ask them whether a kilogram of wool is more in weight or a kilogram of iron, they can answer a kilogram of wool.

Children are not able to repeat the logical steps and if they do so it is in accordance with a habit and not due to reason.


Concrete Operational(7-11)


During this period children learn how to classify things in two or more than two categories. They learn how to perform concrete operations. Concrete operations mean intelligent operations on concrete situations. So children are able to complete puzzles and make objects in the likeness of models.


Children know how to repeat or reverse their actions. For Piaget a genuinely intelligent act can be repeated, is reversible and in concrete operational stage children display this attribute of reversibility.


Children in this age group are able to use reasoning power in concrete situations , but they are not able to use this ability abstractly , means in their imagination .


Formal operation period(11-14)


During this period children develop full reasoning powers and they are able to think in abstract terms. They can solve algebraic problems and can solve problems in their imagination. In this stage reason is developed to its full strength , and whatever a child is not able to do in the earlier stages , he can do in this stage.