Piaget’s Theory of Cognitive Development
Key Constructs:
• Schemes: Knowledge structures
– Simplest schemes are organized patterns of behavior,
including reflexes
• Ex: sucking scheme; looking scheme; grasping scheme
– Become more complex with age and become mental/internal
– Children play an active role in the development of schemes
through their interactions with the environment (constructivist)
• Organization: Inherited predisposition to
combine physical or psychological schemes
into more complex systems
– Ex: infants combine looking and grasping into
a reaching scheme
• Adaptation: Inherited predisposition
involving two processes, assimilation and
accommodation
– Assimilation: Interpret new experiences in
terms of existing schemes
• Ex: Newborns and young infants try to suck many
things, regardless of their “suckability”
• Ex: Child sees a camel at the zoo and yells “horse!”
– Accommodation: Modify schemes to fit new
experiences
• Ex: Infants learn to modify their sucking depending
on the object
• Ex: Child sees a camel at the zoo and yells “Lumpy
horse!”
• 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 (according to
Piaget)
• Will search for a fully occluded (covered) object if
they observe it being hidden
– But still have difficulty solving visible displacement
problems
– A-not-B error: Tendency to reach where objects
have been found before, rather than where they were
last hidden
• Infants make this error until about 12 months of age
– According to Piaget, the A-not-B error occurs
because infants do not have a full understanding of
the permanent existence of the object independent of
its spatial location and their actions on the object
– Between 18-24 months, final stage of object
permanence emerges (according to Piaget)
– Can solve invisible displacement problems
• One object serves as a symbol for a second object
that is hidden from view
General Criticisms of Piaget’s Theory:
• Underestimates the role of specific
experiences in affecting cognitive
development
– Ex: Certain experiences (like formal schooling)
may promote conservation and other abilities
• Doesn’t explain HOW cognitive
development occurs
– Concepts (i.e., schemes, organization,
adaptation) are vague
– Better description than explanation of
children’s cognitive development
• Portrays children’s thinking as being more
consistent than it really is
– Cognitive development occurs more gradually
and shows more variation within children than
Piaget’s theory allows
• Ex: Children can typically solve some conservation
problems sooner than others
• Underestimates the cognitive competence of
infants and young children
– Ex: Object permanence??
Core Knowledge Theories
– Hold that there are specialized learning
mechanisms that allow infants and young
children to acquire certain types of knowledge
quickly
• Ex: Knowledge about object properties such as
solidity and continuity
– two objects cannot occupy the same space; objects follow
continuous paths through space
–
Infants/young children develop “naïve” theories in
certain domains (areas) based on these specialized
learning mechanisms
•
–
Ex: theory of physics (knowledge of physical properties of
objects)
Domains of “core knowledge” have evolutionary
significance
•
Exs: knowledge of people , knowledge of living things,
knowledge of objects
• Violation of Expectation Method
– Based on assumption of infants’ preference for novel stimuli
– Habituate infants to a “possible” physical event
• Habituation: Decrease in response due to repeated presentation of a
stimulus
– Present a “possible” and “impossible” event
• Measure infants’ looking time to each event
• Pits novelty of a stimulus against impossibility of an event
Baillargeon, Spelke, & Wasserman (1985)
• Infants were habituated to a screen rotating up and
then down 180 degrees
• Test trials: Object was placed behind the screen to
block its path
– Screen rotated 112 degrees (possible event) or 180
degrees (impossible event)
– Infants looked longer at impossible event, even though
possible event was (arguably) more novel
• Based on findings using the violation-ofexpectation method with very young
infants, core knowledge theorists claim that
some types of object knowledge are innate
or emerge very early without direct
experience with objects
Issues
• If infants are not fully habituated initially,
may show a preference for the familiar
stimulus during test trials—the more
familiar stimulus is also the “impossible
event”
• Some evidence indicates the presence of familiarity
effects
• Other factors may also be confounded with
the possible and impossible events
– Ex: Degree of movement
• Should infants’ looking behavior be
attributed to higher-order cognitive
processes or does it reflect more “basic”
perceptual processes (e.g., preference for
novelty or familiarity)?
– “Perception and knowing are not the same
thing. . . A person can regard an event as odd
without knowing why” (Haith, 1998)
•
Why does young infants’ behavior differ
from older children’s behavior?
–
Ex: If young infants have object permanence,
then why don’t older infants search for hidden
objects, make the A-not-B error, etc.?
Conclusions (Cohen & Cashon, 2006)
• Evidence is mixed and has been used both
to justify core knowledge theories and more
traditional Piagetian explanations of object
knowledge
• Researchers should focus on understanding
the process of acquiring object permanence,
rather than treating it as an all-or-none
phenomenon
Microgenetic Designs
• Designed to answer questions about how
learning occurs
• Three “essential” characteristics:
– Observations are made across a period of rapidly
changing competence in a particular area
– Within this period, the density of observations is
high relative to the rate of change
– Observations are analyzed intensively to infer
underlying processes
• Microgenetic studies typically involve:
– Relatively small numbers of participants (or
single subject designs)
– Trial-by-trial assessments of children’s
strategies for solving particular types of
problems
– Behavioral observations of strategy use (often
supplemented with self-reports in children 5
years and older)
Overlapping Waves Theory (R. S. Siegler)
• Microgenetic studies across different areas
consistently indicate that children’s thinking
is highly variable
• For example:
– Different children use different strategies
– Individual children use different strategies on
different problems within a single test session
– Individual children use different strategies to
solve the same problem on two occasions close
in time
• According to Overlapping Waves Theory:
– Development is a process of variability, choice, and
change
– Children typically know and use varied strategies for
solving a given problem at any one time
– With age and experience:
• Relative frequency of existing strategies changes
• New strategies are discovered
• Some older strategies are abandoned
– Children usually choose adaptively among
strategies
• Choose strategies that fit the demands of the
problem given the strategies and available
knowledge that children possess
– Choices of strategies become even more
adaptive with experience in a particular content
area
• According to OWT, cognitive change can be
analyzed along five dimensions
– Source of change (causes that set the change in motion)
– Path of change (sequence of knowledge states or
predominant behaviors that children use while gaining
competence)
– Rate of change (how much time or experience separates
initial use of a new strategy from consistent use of it)
– Breadth of change (how widely the new strategy is
generalized to other problems and contexts)
– Variability of change (differences among children in
the other dimensions of change; changing set of
strategies used by individual children)
• Siegler (1995)
– Examined effects of training on strategy use for number
conservation problems (N=45; 54-73 mos., mean = 5.17
years)
– Could add more buttons and make one line a different
length; could take away buttons and make one line a
different length; or could change the length of the line and
not add or take away any buttons
– Random assignment to one of three training conditions
• Feedback only (answer correct/incorrect)
• Feedback plus explain-own-reasoning (“How did you know that?”
followed by feedback)
• Feedback plus explain-experimenter’s reasoning (Feedback followed
by “How do you think I knew that?”)
Findings
• Different Types of Strategies (Explanations)
Used:
– Relative Length: Compare lengths of two rows
– Type of Transformation: Objects
added/subtracted or just moved around
– Counting
– “Don’t know”
• Over the course of the experiment:
– Frequency of length strategies decreased
– Frequency of transformation strategies
increased
– Frequency of counting remained consistently
low
– “I don’t know” first increased and then
decreased
• Source of change
– Combination of feedback and explainexperimenter’s-reasoning led to greater learning
than feedback alone
• Path of change
– Children relied initially on relative length, then
abandoned this strategy but did not adopt a
consistent alternative, then usually adopted the
type of transformation strategy
• Rate of Change
– Most children required multiple sessions to
progress from initial use to consistent use of the
transformation strategy
• Breadth of Change
– Relatively narrow (low generalizability)
• Even some of the best learners continued in the final
session to offer relative length explanations (rather
than transformational explanations) when the longer
row also had more objects
• Variability of change
– Substantial variability within and between
children
• Within children: Only 2% of children relied on a
single strategy throughout the study; 70% used three
or more strategies
• Between children: Individual differences in learning
could be predicted by two pretest measures (total
number of strategies used, whether two strategies
were ever used on the same problem)