2090: Early Cog Dev (13) and

Wynn Development of numerosity

Core Claim (Nativist View)

Wynn argued that infants are born with innate numerical knowledge, sometimes called a “core number system.”

• Infants can represent small quantities (e.g., 1, 2, 3)

• They can perform simple arithmetic expectations (like 1 + 1 = 2)

👉 This knowledge is present very early, not learned from scratch

Key Evidence: Violation of Expectancy

• Infant sees 1 object placed behind a screen

• Then another object is added (1 + 1)

• Screen is lifted to reveal:

  • Possible outcome: 2 objects

  • Impossible outcome: 1 object

Result

• Infants look longer at the impossible outcome

👉 Interpretation:

• Infants expected 2 objects

Suggests basic arithmetic understanding

Wynn U-shaped developmental pattern:

Wynn proposed a U-shaped developmental pattern:

1. Early infancy

   • Strong nonverbal numerical competence

   • Infants succeed in tasks

1. Toddler period (learning language)

   • Performance may decline

   • Number words and language interfere

1. Later development

   • Performance improves again

   • Children integrate language + numerical concepts

Competence vs. Performance

Wynn’s findings support the idea that:

• Infants may have competence (knowledge)

• But their performance fluctuates depending on:

  • Language development

  • Task demands

👉 So:

• Knowledge is not lost, just harder to express at times

Clearfield & Mix

Constructivist VIEW

🧠 Core Idea

Babies do NOT count.

They understand:

• How much stuff there is (amount/size)

They do NOT understand:

• How many things there are (number)

---

🧪 Study Setup

Babies see:

• 2 small squares

• then 1 big square

👉 Both have the same total size (same amount of stuff)

---

👶 What Babies Expect

If babies understood numbers, they would think:

• “2 is different from 1”

👉 They should be surprised

---

👀 What Actually Happens

Babies are NOT surprised
(they don’t look longer)

---

💡 Why?

Because babies think:

• “This is the same amount”

👉 They ignore number and focus on size/amount

---

🎯 Key Finding

Babies track:

• ✅ Amount (how big / how much)

NOT:

• ❌ Number (1 vs 2)

---

🔥 Big Idea

Early thinking =
➡ “Does this look like the same amount?”

NOT
➡ “Is this the same number?”

---

🧩 What develops later

Over time, babies learn:
➡ how to actually count and understand numbers

Top-Down Approach

The top-down approach argues that infants are born with an innate understanding that people act with goals and intentions.

👉 Infants don’t just see movements—they interpret behavior in terms of:

• Goals

• Intentions

Amanda Woodward Study

Method

• Infant sees a hand repeatedly reach for:

  • Frog on red cloth (habituation)

• Then objects switch positions:

  • Frog → gray cloth

  • Duck → red cloth

Test Events

1. Hand reaches for frog (new location) → same goal

2. Hand reaches for duck (old location) → new goal

Results

• Infants do NOT dishabituate to reaching for the frog

• Infants DO dishabituate to reaching for the duck

Conclusion

• Infants care about the goal (frog), not the movement/path

• They interpret actions as intentional

👉 Suggests:

• Infants have innate social-cognitive knowledge

• Supports a top-down, nativist view

Big Takeaway: Infants organize their understanding of the world by inferring intentions, not just tracking physical movements.

Development of Tool Use: Rachel Keen (Spoon Study)

Core Idea

Tool use develops through coordination of:

• Motor control

• Planning

• Understanding tool function

---

🧪 Study Setup

• Infant is given a spoon with food

• Spoon handle faces:

  • Toward dominant hand (easy)

  • Away from dominant hand (awkward)

---

👶 Results by Age Younger infants (~9–14 months)

• Use dominant hand no matter what

• If handle is awkward → still use same hand

• Result:

  • messy

  • inefficient

  • poor success

👉 Behavior = rigid + habit-based

---

Older infants (~18–19 months)

• Switch hands depending on orientation

• Choose the most efficient grip

• Smooth, successful movements

👉 Behavior = flexible + planned

---

🎯 What This Shows

Tool use is NOT just knowing what to do—it requires:

• Goal understanding (get food to mouth)

• Motor planning (how to grab spoon)

• Inhibitory control (don’t just use dominant hand)

• Flexibility (adapt to situation)

---

🔥 Big Developmental Shift

Early:
➡ Action = habit (“I always use this hand”)

Later:
➡ Action = goal-directed (“What’s the best way to succeed?”)

---

🧠 Why This Matters (Link to Theory)

Challenges Jean Piaget in an important way:

• Piaget: knowledge comes from action on the world

• Keen: action itself becomes more intelligent and planned over time

👉 Shows development = interaction of:

• cognition

• motor skills

• experience

Flexible Motor Strategies: Karen Adolph (Handrail Study)

Core Idea

Infants learn to perceive affordances:

• What actions the environment allows or supports

---

Study Setup

• Infants walk across a narrow path

• Conditions:

  • No handrail → too risky

  • Stable wooden handrail → usable

  • Unstable rubber handrail → unreliable

---

Findings

• Experienced walkers:

  • Use stable handrail

  • Avoid unstable one

  • Show understanding of material properties + support

• Novice walkers:

  • Use any handrail, regardless of stability

---

Conclusion

• With experience, infants:

  • Learn about object properties (e.g., solidity)

  • Perceive affordances

  • Make adaptive decisions

Top-Down vs. Bottom-Up in Infant Development

Top-Down Processes (Woodward)

• Infants demonstrate early understanding of goals and intentions

• In Amanda Woodward’s study:

  • Infants habituate to a hand reaching for an object (e.g., frog)

  • When objects switch:

    • Same goal (frog, new location) → no surprise

    • New goal (duck, old location) → surprise

👉 Interpretation:

• Infants encode goal of the action, not just movement/path

• They represent actions as intentional and goal-directed

Key implication:

• Suggests early (possibly innate) social-cognitive knowledge

• Supports a top-down view:

  • Higher-level concepts (intentions, goals) guide perception

  • Infants are not just passive learners

---

Bottom-Up Processes (Keen + Adolph) Rachel Keen (Tool Use – Spoon Study)

• Young infants:

  • Use dominant hand regardless of context

  • Show poor planning + inefficient actions

• By ~18–19 months:

  • Adapt hand use based on spoon orientation

  • Show motor planning + flexibility

👉 Mechanisms involved:

• Motor control development

• Planning ahead (means–end reasoning)

• Inhibitory control (override habitual response)

---

Karen Adolph (Motor Development)

• Infants learn through:

  • Trial and error

  • Perceptual feedback

  • Experience in specific contexts

Example:

• A baby who learns to walk still must relearn balance on slopes or new surfaces

👉 Development is:

• Gradual

• Experience-dependent

• Context-specific (not automatic transfer)

---

⚖ What This Means Theoretically

These findings challenge a strict version of Jean Piaget:

• Piaget emphasized bottom-up construction through action

• But:

  • Woodward → infants show early knowledge before extensive action

  • Keen/Adolph → skills clearly improve through action and experience

Nativist Approaches to Cognitive Development

Nativist ApproachCore Claim

Nativists argue that infants are born with innate “core knowledge” systems, such as:

• Understanding of physical properties (e.g., solidity)

• Understanding of agents and intentions

• Basic numerical abilities

👉 These abilities are thought to be:

• Evolutionarily adaptive

• Present very early in life

---

Key Features

• Emphasize competence > performance

  • Infants know more than they can show

• Use looking-time methods (e.g., violation of expectancy)

• Often interpret findings as evidence for innate knowledge

---

Important Clarification

Nativists don’t usually say experience is irrelevant—
they argue it is not the primary source of core knowledge.

👉 Experience may:

• Trigger or refine knowledge

• But does not fully create it from scratch