Piaget’s stages of intellectual development

• Biological changes in the brain occur through maturation, hence Piaget proposed the ‘ages and stages’ theory as a sequential model of development.
• Three mountains task:


  • Child is asked to select picture of what the doll on other side of the mountains would be able to see.
  • (4 y/o) Children have difficulty with perspective-taking so select the picture of their own view.
  • Egocentric - believing that other viewpoints are the same as own viewpoints.
• Conservation task:


  • Children are shown two equal containers of water, asked whether they contain the same level of water.
  • One of the containers is poured into a longer cylinder and children are again asked if the water is equal.
  • Pre-operational children are dominated by appearances, so say no.
• Conservation: the ability to distinguish between reality and appearance. Pre-operational children lack conservation.
• Stage 1: Sensorimotor stage


  • (0-2 years)
  • Learn to co-ordinate sensory input and motor actions.
  • Infants in this stage lack object permanence - believe that once an object has disappeared from view it ceases to exist.
• Stage 2: Pre-operational stage

  • (2-7 years)
  • Lack of logic-based reasoning means children rely on appearances over reality.
  • Piaget tested this with the conservation task.
  • Pre-operational children are egocentric - lack perspective-taking.
  • Class inclusion: children have difficulty understanding that larger categories contain smaller sub-groups, and multiple sub-groups can be categories simultaneously.
  • Children are shown three black cows and one white, Piaget asked them whether there were more ‘black cows or cows’, pre-operational children said more black cows.
• Stage 3: Concrete operational stage


  • (7-11 years)
  • Children aquire the ability to think logically.
  • Now have conservation.
• Stage 4: formal operational stage


  • (7-11+ years)
  • Children can solve abstract problems using hypothesis and scientific knowledge.
  • Can think idealistically (imagine how things could be if changed).
• Study for AO3: Bryant.


  • Training improved performance - children can be taught material earlier.
  • Reminds that Piaget’s key contribution was to highlight differences between the way adults and children think.
• Study for AO3: Dasen


  • Claims only a third of adults reach abstract logic stage.
  • Criticism for Piaget’s biologically-driven sequence of development.