According to Piaget, the stages
• Involve discontinuous (qualitative) change
• Form an invariant sequence
– Stages are never skipped
Sensorimotor Stage (birth-2 years)
• Newborns have reflexes (motor behavior)
and basic perceptual abilities
– Refine these innate responses (accommodation)
during the first month of life
• Gradually become capable of repeating
satisfying behaviors that initially occurred
by chance
• First learn to repeat actions involving their
own body
– Ex: thumb sucking
• Then learn to repeat actions involving
objects
– Ex: shaking rattle
• Object Permanence: Understanding that
objects continue to exist when they cannot
be perceived directly
– Infants have some understanding of object
permanence at around 8 months
– A-not-B error: Tendency to reach where
objects have been found before, rather than
where they were last hidden
• Suggests full understanding of object permanence is
not present
– Infants make this error until about 12 months of
age
• From 12 months on, infants increasingly
engage in active exploration of objects and
their possible functions
• At end of sensorimotor stage (18-24
months), mental representations develop
– Deferred Imitation: Imitation of a behavior
after a period of delay
• Implies mental representation (memory)
Preoperational Stage (2-7 years)
• Egocentrism: Tendency to focus on one’s
own viewpoint and ignore others’
perspectives
– Ex: 3 Mountains Task
• Centration: Tendency to focus on one
feature of an object or event to the neglect
of other important features
• Conservation: Understanding that certain
physical properties of objects remain the
same even when their outward appearance
changes
• Preoperational children fail conservation
tasks because of
– Centration
– A tendency to focus on static states rather than
transformations
Concrete Operations Stage (7-12 years)
• Understand conservation tasks
– Can focus on multiple features of an object or
event
– Can consider transformations, not just static
states
Limitations of Concrete Operations
– Children’s logical thinking is limited to
concrete information that can be perceived
directly
• Can’t reason about abstract or hypothetical ideas
Formal Operations Stage (12 and older)
• Ability to think abstractly or hypothetically
– “What if . . . ?”
• Can think systematically (scientific
reasoning)
– Ex: pendulum problem
Criticisms of Piaget’s Theory:
• Underestimated role of social environment
in cognitive development
– Ex: Certain experiences (like formal schooling)
may promote conservation and other abilities
• Does not explain HOW cognitive
development occurs
– Better description than explanation of
children’s cognitive development
• The stage model describes children’s
thinking as being more consistent than it
really is
– Ex: Children can solve some conservation
problems sooner than others
• Infants and young children are more
cognitively advanced than Piaget thought
– Ex: deferred imitation (and thus mental
representation) is present earlier than Piaget
thought