Developmental Psych 2


I. Cognitive Development: Piaget vs. Core Knowledge

Piaget viewed infants as active scientists but believed they lacked mental representations early on. Core Knowledge theorists, however, argue infants are born with innate "modules."

  • Object Permanence: Piaget claimed infants don't understand objects exist when out of sight until ~8 months.

  • A-not-B Error: Infants (8–12 months) search for a hidden object where they last found it (Location A) rather than where they last saw it hidden (Location B).

  • Baillargeon’s Rotating Screen: Used the Violation of Expectation method. Infants looked longer at an "impossible" event (a screen rotating through a solid box), proving they have object permanence much earlier (3.5 months) than Piaget thought.

II. Information Processing & Vygotsky

While Piaget focused on stages, these theories focus on the how of thinking.

  • Information Processing: Views the mind like a computer.

    • Task Analysis: Breaking a task down into minute steps to see where a child fails (e.g., is it a memory failure or a motor failure?).

    • Executive Function: The "CEO" of the brain—inhibiting impulses and switching strategies.

  • Vygotsky (Sociocultural):

    • ZPD (Zone of Proximal Development): The gap between what a child can do alone vs. with help.

    • Scaffolding: Temporary support provided by a more knowledgeable other (MKO).

    • Intersubjectivity: The mutual understanding people share during communication.

III. Motor Development & Perception

Motor skills aren't just physical milestones; they change how babies perceive the world.

  • Self-Locomotion: Once infants crawl, they develop a fear of heights (tested via the Visual Cliff) and better spatial coding.

  • Sticky Mittens Study: Infants given velcro mittens to "grab" objects showed earlier interest in objects and better reaching skills later, proving motor experience drives cognitive interest.

IV. Language: From Babbling to Meaning

  • Perceptual Narrowing: Newborns are "citizens of the world"—they can distinguish sounds from all languages. By ~10–12 months, they "tune in" and can only distinguish sounds in their native language.

  • The Mapping Problem: How does a baby know "Bunny" refers to the whole animal and not its tail?

    • Baldwin’s Decoupled Labeling: Shows that infants use joint attention. They look at what the speaker is looking at when a new word is said, rather than just the object they happen to be holding.

V. Temperament & Emotion

  • Mary Rothbart & John Bates Dimensions: Fearful distress, irritable distress, attention span, activity level, and positive affect.

  • Stability: The Dunedin Study showed that temperament at age 3 predicts personality and even financial/legal outcomes in adulthood.

  • Goodness-of-Fit: Development is optimized when the environment/parenting style matches the child’s temperament. (e.g., A "difficult" child needs calm, consistent parenting, not explosive reactions).

VI. Attachment Theory

  • Harlow’s Monkeys: Proved that contact comfort is more important for attachment than food.

The Strange Situation (Ainsworth):

| Attachment Type | Behavior during Reunion | Caregiving Style |

| Secure | Easily comforted, uses parent as secure base | Consistent & Sensitive |

| Insecure-Avoidant | Ignores/avoids parent | Indifferent/Overstimulating |

| Insecure-Resistant | Clingy but angry; unable to be soothed | Inconsistent |

VII. Stress and Family Separation

This section bridges psychology with biology and social policy.

  • Toxic Stress: Chronic activation of the stress response system without adult support. This leads to high Allostatic Load (wear and tear on the body).

  • ACEs (Adverse Childhood Experiences): Higher ACE scores correlate strongly with heart disease, depression, and substance abuse in adulthood.

  • Romanian Orphanages: Children adopted before 6 months usually recovered cognitively; those adopted later often had permanent deficits in social-emotional processing (the "sensitive period" for attachment).