Infancy - Psych 314

Infancy (Birth to ~2 Years) – Key Topics & Concepts

1. Reflexes at Birth

Reflex behaviors occur automatically in response to stimuli and are controlled by lower brain centers. Some disappear over time, while others persist into adulthood.

2. Neonatal Sensory and Perceptive Abilities

Newborns have functional sensory systems, though some develop further after birth.

Taste

• Can distinguish between sweet, sour, salty, and bitter.

• Prefer sweet substances (breast milk).

Smell

• Recognize and prefer mother’s scent within days.

Touch

• Sensitive to pain, soothing touch (swaddling).

• Analgesia is important for medical procedures (e.g., circumcision, heel sticks).

Hearing (Auditory Perception)

• Neonates prefer mother’s voice over others.

• Can distinguish between different phonemes (e.g., “ba” vs. “pa”).

• Prefer familiar stories/music heard in utero.

• Locate sounds (turn head to clicker at 5 minutes old).

Vision

• Blurry at birth, full acuity at 1 year.

• Prefer faces (especially ordered over scrambled faces).

• Depth perception at 2 months (heart rate decrease on the deep side of the visual cliff).

• Avoid crawling off the visual cliff at 6 months (social referencing to caregiver).

3. Motor Development (Birth – 2 Years)

Follows two major principles:

1. Cephalo-Caudal (head-to-tail) – Brain develops before body movement.

   • Grasping before walking.

2. Proximo-Distal (center-to-periphery) – Development moves outward.

   • Rolling over before walking.

Key Motor Milestones

4. Brain Development & Neural Growth

• Synaptic connections form rapidly after birth.

• Myelination of pyramidal fibers (neural pathways connecting the brain to the body) is incomplete at birth and continues into childhood.

• Glial cells play a key role in dendritic spine growth and synaptic plasticity.

• “Use it or lose it” – Synaptic pruning removes unused neural connections.

Major Brain Changes

5. Sleep & Sudden Infant Death Syndrome (SIDS)

• Newborns sleep ~18 hours/day.

• 50% of sleep is REM (essential for brain development).

• Co-sleeping increases SIDS risk (suffocation hazards).

• SIDS Risk Factors:

  • Abnormal brain stem function (serotonin regulation).

  • Sleep apnea, low birth weight.

  • Soft bedding, overheating.

  • Exposure to cigarette smoke.

  • Lack of pacifier use.

6. Nutrition & Breastfeeding

• Infants need ~50 calories per pound/day.

• Introduce foods one at a time to track allergies.

• Progression of food intake:

  1. Milk/formula → 2. Rice cereal → 3. Soft solids → 4. Complex foods

• Breastfeeding Benefits:

  • Lower risk of gastrointestinal infections, respiratory issues, obesity, and SIDS.

  • Breast milk banks for parents unable to nurse.

  • Provides maternal benefits:

    • Lower breast & ovarian cancer risk

    • Reduced risk of Type 2 diabetes

7. Temperament & Attachment

Temperament (Stable Personality Traits)

• Kagen’s Behavioral Inhibition:

  • Shy (Introvert) vs. Outgoing (Extrovert)

• Chess & Thomas’ Temperament Types:

  1. Easy – Adaptable, positive mood.

  2. Difficult – Intense reactions, irregular routines.

  3. Slow-to-warm-up – Low activity, cautious.

Attachment (Ainsworth’s Strange Situation)

• Secure – Upset when caregiver leaves, happy when they return.

• Resistant – Clingy, difficult to soothe.

• Avoidant – Little response to caregiver’s presence or absence.

• Disorganized – Confused, unpredictable reactions (often due to neglect/abuse).

8. Adverse Childhood Experiences (ACES) & Long-term Effects

Key Findings from ACES Study

• 52% of participants had at least one adverse experience.

• High ACES scores correlated with:

  • Mental health issues (depression, anxiety).

  • Physical health issues (obesity, diabetes, cardiovascular disease).

  • Behavioral problems (aggression, impulse control).

Common ACES

• Childhood abuse (physical, emotional, sexual).

• Household substance abuse, mental illness, domestic violence.

• Neglect, poverty, exposure to discrimination.

9. Stress, Cortisol, & Brain Effects

Physiological Stress Response

• Sympathetic Nervous System: Activates “fight-or-flight.”

• Parasympathetic Nervous System: Regulates “rest and digest.”

• Chronic stress leads to:

  • Increased cortisol levels (impairs growth, immunity).

  • Reduced synaptic density (weakened brain connections).

  • Emotional dysregulation (poor impulse control, anxiety).

  • Higher risk for mental disorders (depression, PTSD).

Reversing Effects of Stress

• Enriched environments, exercise, antidepressants can help reverse stress-related brain damage.

Infancy: Cognitive, Social, and Emotional Development

1. Cognitive Development (Piaget’s Theory)

Piaget proposed that infants actively construct knowledge through interaction with their environment.

Key Concepts in Cognitive Development

• Schemes: Mental structures that help organize knowledge.

  • Behavioral Schemes: Actions (e.g., grasping, sucking).

  • Mental Schemes: Internal thought processes.

• Cognitive Processes:

  • Assimilation: Using existing knowledge to interpret new experiences.

  • Accommodation: Modifying schemes to fit new experiences.

  • Equilibration: A process where children transition between stages of thought.

Sensorimotor Stage (0-2 years)

During this stage, infants develop understanding through sensory and motor experiences. The development occurs in six substages:

1. Simple Reflexes (0-1 month)

   • Reflexive behaviors (e.g., sucking, grasping).

   • Reflexes begin to occur without external stimuli.

2. First Habits and Primary Circular Reactions (1-4 months)

   • Reflexes evolve into intentional behaviors.

   • Habits: Repeated actions without a stimulus (e.g., sucking thumb).

   • Primary Circular Reactions: Repetitive actions centered on the body (e.g., kicking legs).

3. Secondary Circular Reactions (4-8 months)

   • Infants begin interacting with the environment.

   • Objects become a focus (e.g., shaking a rattle for sound).

   • Social Smiles appear, indicating awareness of others.

4. Coordination of Secondary Circular Reactions (8-12 months)

   • Goal-directed behavior emerges.

   • Intentionality: Infants separate means from ends.

   • Example: Pulling a cloth to reach a hidden toy.

5. Tertiary Circular Reactions, Novelty, and Curiosity (12-18 months)

   • Infants explore new ways to interact with objects.

   • Trial-and-error problem-solving begins.

   • Example: Dropping different objects from heights to observe effects.

6. Internalization of Schemes (18-24 months)

   • Development of symbolic thought.

   • Deferred Imitation: Imitating behaviors after a delay.

   • Example: Pretending to talk on the phone after watching adults.

Cognitive Milestones

• Object Permanence: Understanding that objects exist even when out of sight.

  • Develops fully by 18-24 months.

  • Before 8 months, infants do not search for hidden objects.

  • A-not-B Error: Tendency to look for objects where they were last found.

• Causality (5-6 months): Infants understand cause-and-effect relationships.

• Infant Categorization:

  • 3-6 months: Recognizes specific objects.

  • 9-12 months: Groups objects into categories (e.g., all animals as "dogs").

2. Language Development

Infants acquire language through both social interaction and innate cognitive mechanisms.

Theories of Language Development

• Behaviorist View (Skinner): Language is learned through reinforcement and imitation.

• Nativist View (Chomsky): Humans have an innate Language Acquisition Device (LAD) for grammar learning.

Language Milestones

1. Crying (from birth): Communicates discomfort and needs.

2. Cooing (3-5 weeks - 4 months): Vowel-like sounds (e.g., "ooo", "ahhh").

3. Babbling (4-6 months): Repetitive consonant-vowel sounds (e.g., "ba-ba", "da-da").

4. Gestures (6 months onward): Pointing, waving, shared attention.

5. First Words (6-12 months): Simple, familiar words (e.g., "mama", "dada").

6. Two-Word Utterances (12-18 months):

   • Telegraphic Speech: "More juice" instead of "I want more juice."

   • Vocabulary expands rapidly (10-12 words per day after 18 months).

Language Learning Mechanisms

• Fast Mapping: Quickly learning new words.

• Overextension: Using a word too broadly (e.g., calling all four-legged animals "dog").

• Underextension: Using a word too narrowly (e.g., only calling the family dog "dog").

• Statistical Learning: Recognizing word patterns to distinguish speech sounds.

3. Social Development

Social behaviors emerge early in infancy and develop through caregiver interactions.

Erikson’s Psychosocial Stages

• Trust vs. Mistrust (0-1 year): Developing a secure attachment to caregivers.

• Autonomy vs. Shame/Doubt (1-3 years): Gaining independence and self-control.

Attachment and Social Interactions

• Separation Anxiety (12-18 months): Distress when separated from caregivers.

• Social Referencing (6-10 months): Looking to caregivers for emotional guidance.

• Joint Attention (9-12 months): Following others' gaze or pointing to share experiences.

Stages of Play

• Solitary Play (2-3 years): Playing alone.

• Parallel Play (2.5-3.5 years): Playing next to others without interaction.

• Associative Play: Sharing toys but no joint activity.

• Cooperative Play: Engaging in shared activities.

Shape Bias - relates to Linda Smith

4. Emotional Development

Infants develop emotions that guide social interactions and self-awareness.

Primary Emotions (from birth)

• Interest, contentment, and disgust.

Basic Emotions (by 2 months)

• Joy, sadness, anger, surprise, and fear.

Self-Conscious Emotions (18-24 months)

• Shame, embarrassment, guilt.

Emotional Regulation

• Begins in early infancy with caregiver interaction.

• Still-Face Paradigm: Infants become distressed when caregivers show no emotion.

Smiling and Social Engagement

• Reflexive Smiles (0-3 weeks): Occur without social cues.

• Pleasure Smiles (3 weeks): Response to pleasurable experiences.

• Social Smiles (6-10 weeks): Response to caregiver interaction.

5. Moral Development

• Innate Morality?

  • Infants prefer helpful individuals over unhelpful ones.

  • Experiments show infants favor "nice" puppets over "mean" puppets.

• Perceptual Narrowing (Race Perception)

  • 3-month-olds prefer faces of their own race.

  • By 9 months, preference for familiar racial groups strengthens.

6. Autism Spectrum Disorder (ASD)

• Early Indicators of ASD:

  • Lack of eye contact.

  • Reduced social engagement.

  • Limited joint attention.

• Brain Differences:

  • Fusiform Face Area (FFA): Face recognition deficits.

  • Amygdala: Affects emotional processing.

  • Superior Temporal Sulcus (STS): Gaze-following issues.

Summary of Key Developmental Milestones

Early Childhood Development (Ages 3-5)

Physical Growth & Motor Development

• Growth Rate: 2.5 inches and 5-7 lbs per year

• Key Influences:

  • Genetics: Ethnic origin plays a role

  • Nutrition: Critical for height and weight

  • Other Factors: Medications, diseases

• Motor Development:

  • Gross Motor Skills: Large movements (running, jumping)

  • Fine Motor Skills: Small movements (drawing, using utensils)

  • Developmental Progression:

    • Age 3: Simple movements, clumsy fine motor skills

    • Age 4: More adventurous, improved control

    • Age 5: Riskier behavior, increased coordination

Key Terms:

• Neophobia: Fear of new foods

• Growth Curve: Used by pediatricians to track normal growth

Nutrition & Sleep

• Healthy eating habits should start early

• Common Nutritional Concerns:

  • Iron Deficiency Anemia: Can increase lead poisoning risk

  • Choking Hazards: Hot dogs, grapes, hard candy—cut food into small pieces

• Sleep Recommendations:

  • 11-13 hours per night

  • Nap Transitions:

    • Infants: 2 naps (morning & afternoon)

    • Preschoolers: 1 afternoon nap (1-2 hours)

Key Terms:

• Malnutrition: Lack of proper nutrition

• Self-Regulation: Ability to control emotions and behaviors

Risks & Early Intervention

• Leading Cause of Injury-Related Death: Firearms (since 2017)

• Early Childhood Special Services:

  • IDEA (Individuals with Disabilities Education Act): Provides early intervention

  • Indiana’s "First Steps" Program: Support for infants/toddlers with developmental delays

Key Terms:

• Developmental Delays: Slower than expected growth in skills

• Early Intervention: Programs that assist children with delays

Preschool Goals & Education Models

• Key Skills Developed:

  • School Readiness: Reading, writing, numeracy, socialization

  • Cognitive & Social Development: Early literacy, number sense, motor skills

• Different Preschool Approaches:

  • Montessori: Structured, self-paced, hands-on learning

  • Waldorf/Steiner: Play-based, natural environment, creative activities

  • Head Start: Designed for low-income families, supports education and nutrition

Key Terms:

• Numeracy: Understanding numbers, spatial concepts, patterns

• Scaffolding: Gradual guidance to help children learn new tasks

Cognitive Development

Piaget’s Preoperational Stage (Ages 2-7)

• Key Characteristics:

  • Egocentrism: Difficulty understanding others' perspectives

  • Animism: Belief that inanimate objects have feelings

  • Centration: Focusing on one aspect while ignoring others

  • Lack of Conservation: Failing to understand quantity remains the same despite appearance changes

Key Terms:

• Theory of Mind (ToM): Understanding that others have different thoughts/feelings

• Symbolic Thought: Ability to use symbols, words, and images

Vygotsky’s Social Constructivist Theory

• Key Concepts:

  • Zone of Proximal Development (ZPD): Tasks a child can do with assistance

  • More Knowledgeable Other (MKO): A skilled individual guiding learning

  • Private Speech: Talking to oneself to solve problems (leads to inner speech)

Key Terms:

• Social Learning: Learning through interaction and observation

• Cognitive Flexibility: Ability to shift thinking and adapt to new situations

Autism Spectrum Disorder (ASD) & Social Development

• Onset: First 3 years of life

• Common Signs:

  • Deficits in social communication

  • Repetitive behaviors and restricted interests

• Theory of Mind Deficit: Difficulty understanding others’ perspectives

Key Terms:

• False Belief Test: Measures understanding that others may hold incorrect beliefs

• Social Reciprocity: Ability to engage in social interactions

Executive Function & Self-Control

• Key Components:

  • Working Memory: Holding information for short-term use

  • Cognitive Flexibility: Adjusting to changes in rules/tasks

  • Inhibitory Control: Resisting impulses (tested with Go/No-Go tasks)

• Marshmallow Test (Walter Mischel): Delayed gratification predicts later success

• Self-Control Can Be Taught: Supportive environments enhance practice

Key Terms:

• Impulse Control: Ability to delay immediate responses

• Delay Discounting: Preference for smaller immediate rewards over larger delayed rewards

Personality, Gender Identity & Moral Development

• Temperament: Early emotional and behavioral traits

• Gender Development: Influenced by genetics, socialization, and cognitive factors

• Moral Development Theories:

  • Piaget: Shift from rigid rule-following to considering intentions

  • Kohlberg’s Stages - thinking behind decisions:

    • Preconventional: Based on consequences

    • Conventional: Based on rules/social approval

    • Postconventional: Based on ethical principles

Key Terms:

• In-group Bias: Preference for one’s own social group

• Autonomous Morality: Understanding rules are made by people

Parenting Styles & Discipline

Baumrind’s Parenting Styles

1. Authoritarian: Strict rules, little warmth → Social incompetence

2. Authoritative: Rules with warmth → Best social competence

3. Neglectful: Uninvolved → Poor self-control

4. Indulgent: Lenient, little discipline → Poor self-regulation

Other Parenting Styles

• Attachment Parenting: Strong bonds, natural approaches (co-sleeping, breastfeeding)

• Helicopter Parenting: Over-involvement in child’s life

• Snowplow Parenting: Removing obstacles for children

Discipline & Moral Behavior

• Spanking is ineffective (linked to aggression)

• Better Strategies:

  • Time-outs (1 minute per year of age)

  • Consistent consequences

  • Reinforcing positive behavior

Key Terms:

• Moral Internalization: Adopting moral values as personal principles

• Prosocial Behavior: Helping, sharing, and cooperating

Study Guide:

• Vygotsky - ZPD, MKO