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 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-of- expectation 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; 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 explain- experimenter’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)