Psych 205 TEST 1- Perceptual Development, Piaget, revisiting Piaget and Socioeconimic theory

What senses are well-developed at birth?

• Touch

• Taste

• Smell

• Hearing (not adult-like, but well-developed)

• Vision is poor at birth but improves in the first few months

What parts of the eye contribute to vision development?

• Retina: Converts light into nervous system signals

• Macula: Small spot in the retina specialized for high-acuity vision

  • Fovea:

  • Contains highest concentration of cone cells

  • Responsible for daylight vision, color vision, and fine detail

• Visual Cortex: Processes visual information from the eyes

What difficulties do infants have with vision?

• Getting the image on the fovea:

  • Lack of convergence: Eyes don’t focus on the same object

  • Slow/imprecise focusing: Image often lands in front of the fovea

• Processing the image:

  • Poor acuity (blurry vision)

  • Poor color vision: Improves by 3-5 months

How does vision develop over time?

• At birth: Stripes appear 30x wider than for adults

• At 8 months: Stripes are 4x wider

• At 6-7 years: Vision reaches adult level

How does the fovea differ between infants and adults?

• Adult Fovea:

  • Tiny spot

  • Sharp daylight vision, fine details, color vision

• Infant Fovea:

  • Twice as wide

  • Immature cones (spread out, catch less light)

Intermodal Perception

Do infants know what sensations go together?

• Sight & Sound

• Sight & Touch

Matching Sight & Sound Studies

Spelke & Owsley (3.5+ months):

• Babies match video of mother or father with corresponding audio

Kuhl & Meltzoff (4 months):

• Babies match mouth movements (ah vs. ee) with the correct sound

Spelke Synchrony Study:

• Babies match slow vs. fast jumping animals with corresponding beats

Meltzoff & Borton (1 month olds):

• Babies suck on nibbed or smooth pacifier → Later look at the one they sucked on

How do we perceive depth?

• Monocular Kinetic Cues (1 eye):

  • Motion Parallax: Closer objects appear to move faster than distant ones

  • Looming: Objects coming closer appear to grow in size

• Binocular Cues (2 eyes):

  • Binocular Disparity: Closer objects have a greater difference between what each eye sees

  • Appears in infants at 4 months

• Monocular Static/Pictorial Cues (1 eye):

  • Interposition: Closer objects block farther ones

  • Relative Size: Closer objects appear larger

How do infants use pictorial cues?

• Baseline condition: Real window tilted → Infants reach for the closer side

• Test condition: Flat trapezoidal window, covering one eye (removing kinetic & binocular cues)

  • 7-month-olds: Reached for larger side (used pictorial cues)

  • 5-month-olds: Reached randomly (not yet using pictorial cues)

Visual Cliff Study

How does experience affect depth perception?

• Setup: Plexiglass illusion of a cliff, caregiver beckons infant

• New crawlers (7 months): Cross both shallow & deep sides

• Experienced crawlers (9 months): Avoid deep side, only cross shallow

• Key Finding: Experience in crawling, not age, determines avoidance of drop

• BUT: New walkers still walk over the edge, showing lack of transfer between locomotion types

Infant Color Vision - Skeleton et al. (2022)

How does color vision develop?

• Newborns: Very little color vision, perceiving bright and large colors when they are born

• Within 6 months: Can recognize, group, and maintain color consistency even with different lighting

• By 4 months: Infants categorically respond to color (e.g., distinguishing blue vs. green)

What is categorical color perception?

What does it mean that infants respond categorically to color?

Infants recognize boundaries between colors

• They distinguish similar shades (e.g., blue vs. green) instead of seeing them as one color

Future Research Directions

What future research direction is interesting?

• Diversifying the sample

• Different cultures and environments expose infants to different color palettes & lighting

• Do babies associate colors with emotions?

Equity & Justice in Color Vision Research

What biases exist in color vision studies?

• Studies rely mostly on WEIRD samples (Western, Educated, Industrialized, Rich, Democratic)

• Norwegian study: Found seasonal & latitude-based differences in color perception

• Key Issue: Lack of diversity may skew findings about universal color perception

Nature vs. Nurture in Color Perception

What evidence supports nature vs. nurture?

• Nature:

  • Biological timing → Infants develop color categorization within 6 months

• Nurture:

  • Norwegian study: Adults from the Arctic Circle distinguish purples better than greens, showing environmental influence

Who was Piaget?

How did Piaget view children?

• Born in French-speaking Switzerland

• Published before graduation

• Worked in Paris with Alfred Binet (intelligence test)

• Interested in children’s mistakes on tests

  • Active learners ("little scientists")

  • Learn independently

  • Intrinsically motivated

Sources of Continuity in Development

Assimilation

• Fitting new information into existing understanding

• Example: Seeing a man with a white beard in red → thinking he’s Santa

2. Accommodation

• Changing understanding to fit new information

• Example: Learning that Santa only comes in winter → modifying belief

3. Equilibration

• Balancing existing knowledge with new experiences

Piaget’s Stage Theory: Key Features

Discontinuous → Stages are qualitatively different
Invariant → Fixed order; no skipping stages
Parallel → Development progresses evenly across cognitive domains

Piaget’s 4 Stages of Cognitive Development

Sensorimotor

preoperational

concrete

Formal operations

Sensorimotor Stage

Birth-2 years)

• Learning through senses & motor actions

• Developing coordination

• Lacks object permanence (objects "disappear" when out of view until ~8 months)

• A-not-B error: Infant keeps looking in the original hiding spot

• Deferred imitation: Imitating observed behavior later

Preoperational Stage

(2-7 years)

• Symbolic representation (imaginative play, language use)

• Limitations:

  • Centration: Focuses on one aspect while ignoring others

  • Lack of conservation: Doesn’t understand that quantity stays the same despite changes in shape/layout

  • Lack of hierarchical classification: Can't organize things into categories

  • Perception bound: Can't think about appearance vs. reality simultaneously

  • Egocentrism: Struggles to see others’ perspectives (3 mountains task)

  • Animistic reasoning: Attributing life-like qualities to inanimate objects

  • Transductive reasoning: Linking unrelated events (e.g., walking makes clouds move)

Concrete Operational Stage

(7-12 years)

• Logical thinking about concrete objects

• Mastery of spatial reasoning

• Can understand conservation, reversibility, and classification

• Still struggles with abstract thinking

Formal Operational Stage

(12+ years)

• Abstract, hypothetical, & scientific reasoning

• Can use analogies & metaphors

• Engages in internal reflection

Revisiting Piaget’s Claims

Why might Piaget’s tasks be difficult for children?

• Language demands: Describing what one would see

• Memory demands: Remembering other perspectives (e.g., Three Mountains Task)

• Task setup demands: Allowing kids to manipulate objects might help

• Sample limitations: Piaget tested a small sample

Sensorimotor Stage - Object Permanence

Piaget’s Claim: Infants do not search for hidden objects until 8 months → No object permanence

Alternative Explanation?

• Violation of expectation method: Infants look longer at impossible events

• Rolling Cart Study:

  • 6.5- & 8-month-olds looked longer at the impossible event → Object permanence at 6.5 months

  • Motor constraints may explain why younger infants fail Piaget’s task

Minnie Mouse Study

Tested 3- & 3.5-month-olds

• Impossible event: Minnie passes through a window gap but is not seen

• Possible event: Minnie passes behind a cover

Results:

• 3-month-olds were surprised by the impossible event

• 3.5-month-olds were not surprised → May have generated an explanation

Conclusion: Even young infants have more knowledge than Piaget thought

Modified Number Conservation Task

4-5-year-olds, two conditions:

1. Standard (unit labels, e.g., "soldiers") → Kids did poorly

2. Modified (group labels, e.g., "army") → Kids did better

Why?

• Labeling as a group helped kids focus on changes to the whole group rather than individual units

Modified Egocentrism Task

Modifications to Piaget’s Three Mountains Task:

• Burke (1975): Used a farm scene & asked kids to describe what “Grover” sees → 4-year-olds did better

• Cat-Dog Experiment:

  • 3-4-year-olds used double-faced cards

  • Asked: “What do you see? What do I see?”

  • Kids did better than in Piaget’s version (simpler task)

Piaget’s Claims on Development

Development is Discontinuous (Stage-based)

• Piaget: Thinking develops in distinct stages

2. Development is Parallel Across Areas

• Piaget: If a child is in one stage, they should fail all tasks of that stage

• BUT: Children do not fail all conservation tasks at once → NO parallel development

Conclusions on Piaget’s Theory

• Piaget pioneered child psychology

• BUT his stage theory:

  • Fails to predict children's responses

  • Doesn’t account for variability in performance

• Children are more competent than Piaget believed

• Performance depends on task structure & experience

Core Knowledge Perspective

Core domains of thought → Infants are born with innate knowledge in key areas:

1. Physical (understanding objects)

2. Numerical (basic number sense)

3. Linguistic (language knowledge)

4. Psychological (understanding others’ mental states)

5. Biological (knowledge of living things)

Key ideas:

• Active learners → Learn by interacting with the world

• Domain-specific → Develop at different rates in different areas

Physical Knowledge

Violation of Expectation Method:

• Kids look longer at impossible events

• By 3 months, infants expect objects to fall

• Older infants tolerate some unsupported objects (e.g., if touched by a finger) but then are shook when the finger is taken off

Numerical Knowledge

Infants’ Arithmetic (Wynn, 1992)

• 5-month-olds, Violation of Expectation Method

• 1+1 Task: Expect 2 objects, surprised if only 1 appears

• 2-1 Task: Expect 1 object, surprised if 2 remain

Approximate Number System (Xu & Spelke, 2000)

• 6-month-olds discriminate large number differences (e.g., 8 vs. 16)

• But not small ones (e.g., 8 vs. 12)

Biological Knowledge

Living vs. Non-Living (Ricard & Allard, 1993)

• 9-10-month-olds react differently to:

  • Animals (rabbit) → More touching

  • People (stranger) → More looking & smiling

  • Objects (wooden turtle) → Less engagement

Limitations:

• Plants → Preschoolers know they grow, heal, and die but don’t think they’re alive

Teleological Reasoning (Opfer & Gelman, 2003)

• Preschoolers: Believe animals are more purposeful than objects

• 5th graders: Recognize non-living things can have designed functions

Biological Processes

• Inheritance: Kids understand physical traits are passed down

• Essentialism: Living things have an inner "essence" that defines them

Picture Book Study (Coleman)

• 5-8-year-olds

• Tested on natural selection knowledge

• Found improvement after reading the book & even 3 months later

Information Processing Theories

Focus on:

• Specific cognitive processes over time

• Continuous development (small changes accumulate)

Views of Children:

• Limited-capacity processors

• Problem solvers

Overlapping Waves Theory

• Kids try multiple strategies before settling on the most efficient one

• Example: Learning multiplication—using fingers, then memorization

Vygotsky's Sociocultural Theory

Key Ideas:

• Children are social learners

• Adults & peers play a role in development

• Learning happens in context (culture matters!)

• Development is continuous, not stage-based

• Guided participation: More knowledgeable individuals help children learn