Theories of Cognitive Development, Including Piaget and Vygotsky


  • The idea that we are born with basic skills to allow for cognitive development that grow as we become older.
  • He believed that the child underwent two processes:
    • Accommodation– When a schema is altered in order to fit in new information i.e. learning that birds don’t have to fly to be birds. At this point, the child is in disequilibrium.
    • Assimilation– When new information is able to be fitted into an existing schema. At this point, the child is in equilibrium.
  • Disequilibrium is an uncomfortable mental state which is made better by being in equilibrium.
  • Stages of Cognitive Development:
    • Sensorimotor– Birth-10 months. Lack of an understanding of object permanence (things out of sight are not believed to exist). Develop the ability to form schemas based on the sensation an action produces i.e. putting object in mouth forms a Mental Representation.
    • Pre-Operational– 18 months- 6 years. Begin to operationalise (think through actions before carrying them out). Able to communicate but only about their own opinions and are Egocentric (can only see things from their own perspective). They also don’t understand conservation, when things are arranged differently, the quantity, volume and number remain the same (*** is the same as * *  *). Can also not focus on more than one task at once, Centration. Two stages: Pre-conceptual phase and Intuitive phase.
    • Concrete Operational– 6 years- 12 years. Begin to perform mental operations and reason logically and use inductive logic where they apply their knowledge to different situations. Become decentred where they are able to focus on more than one task at a time. Understand that an action can be reversed. Unable to use transitive inference as they cannot make logical deductions i.e. A before B, B before C, so A is first.
    • Formal Operational- 12 years onwards. Can undertake formal operations where they do not have to perform an action to imagine the consequences. Used to formulate hypotheses.


  • Bower– Found that object permanence occurred earlier than Piaget had originally thought as children were displaying it as early as 3.5 months.
  • Meltzoff & Moore– Mental representations occurred earlier than Piaget thought. Children 6 weeks old were able to imitate an expression, showing their ability to form a mental representation of the gesture.
  • Children aged 3 were able to hide a doll away from toy policemen which requires egocentrism, however Piaget thought that this developed a lot later.
  • Change of Piaget’s counter study showed children below the age of 6 showing conservation.
  • Not all reach the formal operational stage (I in 3) and this was even lower for non-westernised cultures-> cultural bias.
  • IDASà Nature/ Nurture, Limited, Reductionist, Determinism, Cultural Bias


  • Believed that social activity is what children need to develop cognition.
  • Stages of Cognitive Development- Stages of concept formation
    • Vague Syncretic- No organised grouping of items and no understanding of categories. Trial and error is used to solve problems.
    • Complex- Begin to understand grouping and strategies become less random. Correct category is usually not selected though i.e. animal category used for duck and water because of the close association of the two things.
    • Potential Concept- Grouping and systematic approaches are used but only on one concept at a time i.e. an item only belongs to one
    • Mature Concept- Grouping and systematic approaches are used simultaneously.
  • Stages of Language Development-
    • Pre-intellectual Speech– 0-3 years. Language and cognition are separate. Speech is only used to communicate survival needs i.e. hunger.
    • Egocentric Speech- 3-7 years. Language is developed and is used as a method of problem solving. Speech is projected out loud to express the child’s thought processes.
    • Inner Speech- 7 years onwards. Language is used more effectively and the child becomes capable of holding a silent, inner conversation.
  • Zone of Proximal Development- Area that a child must enter in order to improve cognition.
    • 1) Current ability of the child and what they can do on their own.
    • 2) Zone of Proximal Development. Child must pass through this stage in order to unlock potential development. Scaffolding is needed by mentor.
    • 3) Region of ability that the child does not yet possess. Becomes new ZPD after the current one is reached.


  • Scaffolding was directly correlated with the difficulty of a jigsaw. When level got harder more scaffolding was needed to cross ZPD threshold.
  • Studies may have been affected by the group or individual basis. Competitiveness is not encouraged in groups. Different children used in different groups so could be due to individual differences.
  • May be an over emphasis on social factors so things like self discovery may be more important.
  • Suggests that scaffolding is necessary for a child to develop cognition.
  • IDASà Nature/ Nurture, Limited, Reductionist, Determinism, Cultural Bias