Children’s Thinking

Lecture 3Methodological Preliminaries

Introduction to Piaget

Observation vs. Experimentation, redux

• Naturalistic observation allowed researchers to establish norms for basic milestones of physical & behavioral growth.

• BUT observation alone is very limited in explanatory power – cannot probe behavior to uncover its mental foundations.

• Experimentation (especially w/infants) provides compelling vistas on children’s thinking and has provided radically new views on infants’ and children’s cognitive capacities and functioning.

Research strategies:Longitudinal vs. Cross-Sectional

Cross-sectionalAge 1 Age 2 Age 3

LongitudinalAge 1 Age 2 Age 3

Longitudinal Research: Benefits

• Most ‘natural’ strategy – grows from case studies

• Provides individual history – can see developmental & environmental precedents

• Common in observational studies• Individuals serve as their own controls

– minimize individual differences that add noise to comparisons and maximize statistical power

Longitudinal Research: Costs

• Slow – have to wait for subjects to reach appropriate ages

• Subject “mortality” – families lose interest or move out of area, etc.; consequently, the sample at the end of the study is inevitably (much) smaller than the initial sample.

Cross-Sectional Research

• Benefit: by observing different groups of children at different ages, research can be completed more efficiently.

• Assumption: as members of the same species, we share essential cognitive abilities, processes, and representations

• Most common in experimental research• Costs

– Individual differences are not just “noise”– Sense of history is lost

Fundamental Definitions:What is Development?

• Change of a certain sort– Orderly– Directional– Cumulative

• Behavior becomes more flexible and complex

• Behavior involves increasing differentiation and integration

Fundamental Definitions:What is Cognition?

• We usually use “thinking” to refer to higher order mental processes like judgment, problem solving, conceptualizing, etc.

• Here, we are concerned not only with these, but also with basic aspects of everyday mental processing.

• These include:– remembering– recognizing objects as exemplars of particular

categories of objects – representing the external world

Part 2

• How can we put together observational and experimental findings, using both longitudinal and cross-sectional strategies, to derive an account of children’s cognitive development?

• Let’s start with the seminal figure in the field, Jean Piaget

Jean Piaget: Master Observer

The Object ConceptImplicit beliefs we all hold about objects.•We, and all other objects, coexist as

physically distinct and independent entities within a common, all enveloping space

•The existence of our fellow objects is fundamentally independent of our own interaction or non-interaction with them

•An object’s behavior and existence is independent of our psychological contact with it

Infants’ Object Concept, Stage 1

(0-1 months)

Object Concept, Stage 2(1-4 months)

• Passive expectation: if object disappears, infant will continue looking to the location where it disappeared, but will not search.

• In the infant mind, the existence of the object still very closely tied to schemes applied to experience

Object Concept, Stage 3(4-8 months)

• Visual anticipation.• If infant drops an object, and it

disappears, the infant will visually search for it.

• Will also search for partially hidden objects

• But will not search for completely hidden objects.

Object Concept, Stage 4(8-12 months)

• Infant will search for hidden object.• Does the infant understand the

object as something that exists separate from the scheme applied to find the object? (“Scheme” is the term that Piaget used for “action” or “behavior”)

• No. Evidence? “A-not-B” error.

A trials

The A-not-B task

1

A trials

The A-not-B task

1

A trials

The A-not-B task

1

A trials

The A-not-B task

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A trials

The A-not-B task

2

A trials

The A-not-B task

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B trials

The A-not-B task

B trials

The A-not-B task

B trials

The A not B task

??

A-not-B error

• Infant continues to search at the first hiding location after object is hidden in the new location.

• This indicates that objects are still understood only subjectively.

• Reappearance of the object remains associated with a previously successful scheme.

Object Concept, Stage 5.(12-18 months)

• Can solve A-not-B.• Cannot solve A-not-B with invisible

displacement.• Can only imagine the object as

existing where it was last hidden.• Invisible displacement requires the

infant to mentally calculate the new location of the object.

• Mental representation appears as the hallmark of Stage 6.

Piaget, The Theorist

• Piaget made observations on a wide variety of behavioral phenomena, often inventing informal experiments to draw out critical performances.

• Piaget offered a grand constructivist theory of cognitive development, in which the child is seen as an active agent of his or her own mental growth.

Active view of development

• Child as scientist• Mental structures intrinsically active

constantly in need of being applied to experience

• Leads to curiosity and the desire to know more

• Development proceeds as the child actively refines his/her knowledge of the world through many “small experiments”

How does Piaget describe developmental change?

• Development occurs in stages, with a qualitative shift in the organization and complexity of cognition at each stage.

• Thus, children not simply slower, or less knowledgeable than adults instead, they understand the world in a qualitatively different way.

• Stages form an invariant sequence.