Piaget's Stages of Cognitive Development

The four stages

• Piaget's theory helps explain how our knowledge of the world is acquired through schema and disequilibrium/equilibration
• He also believed that cognitive development is the result of four separate stages, each of which need different levels of reasoning ability
• Exact ages of children who go through these stages vary from child to child, but he stated that every child goes through these stages

Sensorimotor stage: 0-2 years

• A baby's focus is on phyical sensations and basic co-ordination between what they see and their body movement
• Babies also begin to understand that other people are separate objects
  
• They acquire basic language
• They also develop object permanence, which is the undrstanding that an object is still there, even when it is out of sight

Supporting evidence: Piaget found that object permanence develops around eight months. Before this time, children don't reach for an object that has been covered by a blanket.

Counter-evidence: Bower and Wishart (1972) found that infants aged one to four months old continued to reach for an object up to 90 seconds after the lights had been turned off. This counter-evidence criticises Piaget, because the baby may have been distracted by the blanket in Piaget's study, making the findings unreliable. This means object permanence must occur at a much younger age than Piaget theorised.

Pre-operational stage: 2-7 years

• Children learn to conserve in this stage i.e. they begin to understand that quantity remains constant when the appearance of an object changes

Supporting evidence: Piaget found that if an equal amount of liquid was put into a small fat vessel and a tall thin vessel, children tended to say there was more liquid in the tall thin vessel.

Counter-evidence: McGarrigle and Donaldson (1974) made a 'naughty teddy' move an arrangement of counters to make them more spread out, 62% of children said there was the same number of counters as before. This shows…