Developmental Psychology Notes

What is Developmental Psychology?

• Psychology: The study of mental processes & behavior.
• Developmental Psychology: The study of physical and psychological changes over time.
  • Three Areas of Development:
    • Physical
    • Cognitive
    • Socio-emotional

Developmental Periods

Key Themes in Child Development

1. Nature and Nurture
   • Nature: Genetic inheritance
   • Nurture: Environment and experiences
   • Development is shaped by both.
2. The Active Child
   • Children influence their own development (not just passive recipients).
3. Continuity and Discontinuity
   • Continuous: Gradual changes (e.g., vocabulary growth)
   • Discontinuous: Stage theories (e.g., Piaget); qualitatively different stages
   • Domain-general vs. Domain-specific
4. Sociocultural Context
   • Influence of culture, ethnicity, SES, and social factors on development.
5. Individual Differences
   • Why children differ in temperament, behavior, and outcomes.

The Scientific Method in Developmental Research

• Goals: Describe, explain, predict behavior; answer practical questions.
• Types of Research:
  • Basic Research: Increases fundamental knowledge.
  • Applied Research: Solves practical problems.

Key Concepts:

• Objectivity: Eliminate bias (e.g., blind observers)
• Reliability:
  • Test-retest reliability
  • Interrater reliability
• Replicability: Repeatability of findings.
• Validity:
  • Construct Validity: Measures what it claims.
  • Internal Validity: Control for variables to determine cause.
  • External Validity: Generalizability to population.

Sampling in Research

• Population: Entire group of interest.
• Sample: Subgroup used for study; must be representative to ensure external validity.

Example Pitfalls:

• Biased samples can lead to misleading generalizations (e.g., using only children from a clinic or one SES group).

Methods of Data Collection

• Naturalistic Observation: Real-world settings.
• Structured Observation: Controlled environment.
• Best Practice: Use multiple sources for data collection.

Research Designs

1. Correlational Design
   • What it tells us:
     • Whether variables are related
     • Direction and strength of relationship
   • What it doesn’t tell us:
     • Causation
     • Could be influenced by a third variable
   • Example: Does amount of exercise relate to sleep quality or school success?
   • Correlation ≠ Causation
2. Experimental Design
   • Purpose: Test causal relationships via manipulation.
   • Variables:
     • Independent Variable (IV): What’s changed (e.g., type of video)
     • Dependent Variable (DV): Outcome measured (e.g., aggression)
   • Key Concept: Random assignment to control vs. experimental groups

Bandura’s Bobo Doll Study

• Research question: Do children imitate aggression?
• Design:
  • IV: Type of video (aggressive vs. non-aggressive)
  • DV: Aggressive behavior toward the doll
• Finding: Kids exposed to aggression imitated it → supports observational learning

Studying Change Over Time

1. Longitudinal Design
   • Same group tracked across multiple ages
   • Pros: Individual progress tracked
   • Cons: Time-consuming, expensive, attrition, low external validity
2. Cross-Sectional Design
   • Different age groups studied at one point in time
   • Pros: Quicker, cheaper
   • Cons: Can’t track individual change, cohort effects
3. Microgenetic Design
   • Focus on short periods of rapid change
   • Often used in training studies

Ethics in Developmental Research

• Informed Consent
• Confidentiality
• Debriefing
• Deception (must be justified and explained after the study)

Lecture Aims / Goals

• Understand theoretical foundations of attachment theory.
• Explain the Strange Situation and how it is used to identify attachment styles.
• Recognize how infant attachment styles can remain stable across the lifespan.

What Is Attachment?

• Definition: An emotional bond between an infant and their primary caregiver.
• Purpose: Provides security, shapes social and emotional development.

Theoretical Perspectives on Attachment

1. Psychoanalytic Theory (Freud)
   • Early interactions with caregivers shape later relationships.
   • Attachment driven by hunger drive (need for nourishment).
2. Ethology (Biological Perspective)
   • Attachment is a biologically programmed response.
   • Based on imprinting principles (automatic bonding).

Observations from Isolation Studies

Rene Spitz (1940s)

• Studied institutionalized children (well-fed, but deprived of touch).
• Findings:
  • Despite good physical care, 1/3 of infants died.
  • Highlighted the need for emotional warmth and contact.

Harlow's Monkey Study (1971)

• Infant monkeys preferred soft, comforting surrogate mothers over wire mothers with food.
• Proved attachment is based on contact comfort, not just food.

Bowlby’s Attachment Theory

Why do infants attach?

• Not just for food/survival — they need social interaction.
• Influenced by ethology + psychoanalysis.

Bowlby’s Four Phases of Attachment:

Measuring Attachment: The Strange Situation (Mary Ainsworth)

What is it?

• A structured observation that evaluates how infants use the caregiver as a secure base.
• Involves separations and reunions with caregiver in a lab setting.

Attachment Styles:

How Attachment Develops

• Attachment is based on expectations learned from early interactions:
  • Warm, responsive caregiver → Secure attachment
  • Inconsistent, overbearing caregiver → Anxious attachment
  • Cold, rejecting caregiver → Avoidant attachment

Attachment Across the Lifespan

Shifts in Attachment Figures:

• From parents → peers → romantic partners
• Functions remain: emotional support, comfort, guidance.

Adult Attachment Styles

Sample Self-Reflection (Used in Research)

Which best describes your romantic relationships?

1. Secure
2. Avoidant
3. Anxious

Attachment in Orphans

• Orphaned children may lack early secure attachments, leading to social-emotional difficulties.
• However, later peer and partner relationships can serve as new attachment figures.

Lecture Outline

1. Genes and environment
2. Prenatal development
3. Effects of the prenatal environment
4. Assessing and caring for babies at risk

Genes and Environment

Key Terms:

• Genotype: An individual’s complete set of inherited genes.
• Phenotype: The observable traits (e.g., behavior, appearance) resulting from interaction between genotype and environment.

Genetic Disorders:

• Down Syndrome (Trisomy 21): Caused by an extra 21st chromosome.
• Williams Syndrome: Rare genetic condition affecting cognitive development.
• Huntington’s Disease: Inherited disorder causing degeneration of nerve cells.

Behavioral Genetics:

• Twin studies help explore genetic vs. environmental influences.

Prenatal Development

Two Perspectives:

• Medical (mother-focused): Trimesters, counted from last menstrual period.
• Developmental (baby-focused): Stages counted from conception.

Three Stages of Prenatal Development:

Germinal Period:

• Begins with zygote, progresses to morula, then blastocyst.
• Trophoblast becomes amniotic sac, placenta, umbilical cord.
• Implantation occurs near end of this period.

Embryonic Period:

• Inner cell mass forms 3 germ layers:
  • Ectoderm (outer): Skin, nervous system, hair, teeth
  • Mesoderm (middle): Muscles, bones, circulatory and reproductive systems
  • Endoderm (inner): Digestive and respiratory systems

Fetal Period:

• Month 3: Body parts identifiable.
• Months 4–6: Brain growth; mother feels movement (quickening).
• Months 7–9: Respiratory system matures; fetus gains weight.
• Rapid growth in muscle and bone.

Effects of the Prenatal Environment

Teratogens:

• Definition: Environmental agents causing birth defects.
• Severity depends on:
  • Genetic susceptibility
  • Dose
  • Timing of exposure
• Examples: Drugs, alcohol, stress, nutrition

Timing Matters:

• Different teratogens affect development depending on when exposure occurs (critical periods).

Maternal Characteristics:

• Age: Mothers under 15 have higher infant mortality risk.
• Nutrition: Folic acid deficiency can cause spina bifida.
• Stress: Linked to hyperactive, irritable newborns with sleep and feeding issues.

Drug Effects:

Assessing and Caring for At-Risk Newborns

Apgar Scale:

• Assesses health at birth (appearance, pulse, grimace, activity, respiration).
• Taken at 1 and 5 minutes post-delivery.

Gestational Age:

• Full term: 37–42 weeks gestational age
• Viability: 22–26 weeks (the earliest a baby can survive outside womb)

Birth Weight Categories:

Prematurity & SGA (Small for Gestational Age):

• Preterm: Born before 37 weeks
• SGA: Weight below norm for gestational age

Potential Consequences:

• Nervous system damage
• Lung/liver disease
• ADHD
• Learning disabilities
• Breathing issues

Supportive Interventions:

• Compensatory stimulation:
  • Mimic womb sensations
  • Touch therapies like massage
  • Sensory enrichment to support development

The Visual System

Major Parts of the Eye:

Rods vs. Cones:

Sensory & Perceptual Development in Newborns

• Question: Do newborns perceive like adults?
• Answer: They have some sensory abilities but not fully developed perception.

How do researchers test infant perception?

1. Visual Preference Paradigm
   • Infants tend to look longer at preferred or interesting stimuli.
2. Habituation
   • Decreased response to repeated stimulus.
   • Dishabituation: Renewed response when a new stimulus is introduced.

Newborn Visual Preferences:

• Movement
• Contrast (contour)
• Symmetry
• Complexity
• Faces, especially attractive ones

Visual Perception

Depth Perception:

• Tested using the Visual Cliff experiment.
• Demonstrates that infants can perceive depth (avoid crawling over "deep" side).

Sensory Capabilities at Birth

"Cat in the Hat" Study (DeCasper & Spence)

• Moms read “Cat in the Hat” aloud during pregnancy.
• After birth, babies sucked in a way to hear the familiar story — shows prenatal learning and memory.

Motor Development

Reflexes (Inborn Responses):

• Grasping
• Sucking
• Rooting (turning toward touch near mouth)

Rhythmical Stereotypies:

• Repetitive movements with no clear purpose (e.g., kicking, waving arms).

From Reflexes to Voluntary Control:

• Motor control gradually shifts from reflex-driven to voluntary movements.

Cultural Differences:

Focus of Research

• Child sexual abuse cases are the main area of study.
• Goal: Balance between obtaining accurate, complete disclosures vs. avoiding false reports.

Types of Reports

Key Factors Affecting Child Witnesses

1. Age
   • Most consistent predictor of memory accuracy and suggestibility.
   • Younger children:
     • Remember less
     • Are more vulnerable to suggestion
2. Age at Time of Event
   • Infantile amnesia: Inability to recall events before age 3–4
3. Age at Time of Interview
   • Preschoolers can remember single/repeated events but:
     • Provide less detail
     • Make more errors to leading/suggestive questions

Best Practice Interview Guidelines

Start With:

• Instructions, not assumptions:
  • “It’s okay to say ‘I don’t know.’”
  • “You can correct me if I get something wrong.”

Build Rapport:

• Ask about:
  • Things they like to do
  • Things they don’t like
  • A recent birthday experience

Use Open-Ended Prompts:

• “Tell me more about… ”
• “What did you do next?”

Introducing the Allegation (Examples)

• “Tell me why your mom brought you to talk to me today.”
• “I heard you talked to a police officer. What did you talk about?”
• “My job is to learn about things that happened. Can you help me understand why you're here?”

Types of Questions

Language to Avoid

• Words and phrases that are:
  • Ambiguous (e.g., pronouns: "he," "that")
  • Abstract (e.g., "touch," "house")
  • Time-related (e.g., before/after, yesterday/today)

Suggestive or Misleading Questions

Problematic phrases include:

• Leading assumptions: “He was wearing the magic cape, wasn’t he?”
• Presumed events: “Where did you and the man go for lunch?” (assumes the event happened)
• Embedded clauses: “All the other kids told me everything, now it’s your turn.”
• Real case example:
  • State of New Jersey v. Michaels (1994): Interviewers used pressure, suggestion, and leading prompts which risked contaminating children's testimonies.

What Is Cognition?

• Cognition: All mental activities related to thinking, knowing, remembering, and communicating.
• Cognitive development: Changes in these abilities across the lifespan.

Four Major Theories of Cognitive Development

1. Piaget’s Theory
2. Vygotsky’s Sociocultural Theory
3. Information-Processing Theories
4. Core-Knowledge Theories

Piaget’s Theory: Child as a Scientist

Key Concepts:

• Constructivism: Children actively construct knowledge through interaction with the world.
• Schemas: Mental structures for organizing information.
• Assimilation: Interpreting new info using existing schemas.
• Accommodation: Modifying schemas to fit new information.

Piaget’s 4 Stages:

Supporting Research:

• A-not-B task: Infants fail to search correctly after object is hidden in new location.
• Wynn's addition study: Infants may understand number earlier than Piaget thought.
• Theory of Mind: Understanding others' thoughts develops around age 4 (e.g., Sally-Anne task).

Vygotsky’s Sociocultural Theory: Child as a Product of Culture

Key Concepts:

• Cognitive development is shaped by social interaction and culture.
• Zone of Proximal Development (ZPD): Gap between what a child can do alone vs. with help.
• Social Scaffolding: Support given by more knowledgeable individuals to help a child reach a higher level.
• Cultural Tools: Language and other tools used to mediate thought.
  • Private speech → Inner speech (self-regulation and thought).

Information-Processing Theories: Child as a Computational System

Core Ideas:

• Development = overcoming limitations in processing capacity.
• Influenced by biological maturation (e.g., myelination, brain connectivity).

Components of Memory:

Mental Strategies:

• Rehearsal: Repeating info.
• Selective Attention: Focusing on relevant info.
• Overlapping-Waves Model: Children use multiple strategies and gradually rely on more effective ones.

Core-Knowledge Theories: Child as an Evolutionary Product

Emphasis:

• Infants are born with domain-specific knowledge systems (e.g., face recognition, language).
• Children’s reasoning in some areas is more advanced than Piaget believed.

Evidence:

• Face preference in newborns.
• Universal language acquisition and specialized brain areas.
• Naive theories:
  • Physics (early object understanding)
  • Psychology (~18 months)
  • Biology (~3 years)

Comparison of Theories

What Are Emotions?

• Subjective reactions with three components:
  1. Cognitive – experienced as pleasant/unpleasant
  2. Physiological – bodily responses
  3. Behavioral – facial expressions

Ekman’s 6 Basic Emotions (Universal & Evolutionary)

1. Anger
2. Fear
3. Disgust
4. Surprise
5. Joy
6. Sadness

Positive Emotions in Infancy

• Smiling: First sign of happiness
  • Social smile (6–7 weeks): Directed at people
• Laughter appears by ~3–4 months
• At 7 months: Preferential smiling at familiar people
• By 2 years: Toddlers enjoy making others laugh

Negative Emotions in Infancy

• General distress is the earliest form
• By 2 months: Facial expressions differentiate into anger, sadness, and pain
• By 2 years: Emotions become easier to distinguish

Fear and Anxiety

• Fear of strangers: Emerges ~6–7 months, peaks ~2 years
• Separation anxiety:
  • Distress when separated from caregiver
  • Peaks between 8–15 months
  • Observed across cultures

Social Referencing

• By 12 months: Infants look to caregivers to interpret ambiguous situations
  • Positive parent emotions → infant approaches
  • Negative parent emotions → infant avoids

Learned Disgust

• Children learn disgust through observation and parental cues.

Emotion Regulation

Definition:

• The process of modifying internal emotional states, including:
  • Cognitive
  • Physiological
  • Behavioral aspects

Developmental Patterns:

1. Infancy:
   • Relies on caregiver regulation (e.g., soothing, distraction)
   • Early behaviors: gaze aversion, self-soothing
2. Preschool years:
   • Can self-regulate (e.g., talk about feelings, play alone, negotiate)
   • Supported by brain development and parental expectations
3. School-age:
   • Use cognitive strategies and distinguish between controllable and uncontrollable situations

Self-Conscious Emotions

• Includes: Guilt, Shame, Embarrassment, Pride
• Emerge around 15–24 months
  • Embarrassment when made the center of attention
• By 3 years: Pride linked to performance
• Cultural differences affect which situations trigger these emotions

Emotional Development by Age

Parenting and Emotional Development

Parental Emotion Expression:

• Positive emotion at home → better child outcomes
• Negative emotion-dominant homes → poor social competence, more negativity in child

Parental Reactions to Emotions:

• Dismissing/criticizing emotions = lower emotional competence in child
• Emotionally supportive parents → better outcomes

Emotion Talk:

• Family conversations about feelings help children understand and express emotions
• Especially effective when supportive, not hostile

Temperament

Definition:

• Constitutionally based individual differences in emotional, motor, and attentional reactivity and self-regulation
• Stable across time and contexts

Thomas & Chess Temperament Types:

1. Easy babies (40%): Adaptable, positive mood, regular routines
2. Difficult babies (10%): Intense, irregular, negative mood
3. Slow-to-warm-up (15%): Low activity, somewhat negative, slow to adapt

Rothbart’s 6 Dimensions of Temperament:

1. Fearful distress
2. Irritable distress
3. Attention span/persistence
4. Activity level
5. Positive affect
6. Rhythmicity

Stability and Outcomes:

• Inhibited infants at age 2 show:
  • Higher fear
  • Social inhibition at 4½
  • Later risks: anxiety, depression, withdrawal

Development of the Self

Infancy (18–30 months)

• Self-recognition in mirror by 18–20 months
• By 30 months, recognize self in photographs
• Behaviors like embarrassment, shame, and self-assertion reflect self-awareness

Early Childhood

• Ages 3–4: Self-descriptions focus on observable traits (e.g., physical, activities)
• Unrealistically positive self-evaluations

Middle Childhood

• Begin social comparisons (comparing themselves to peers)

Adolescence

• Develop personal fable: belief in one’s uniqueness and invulnerability
• Imaginary audience: belief that others are constantly watching/judging them

Identity Development

What is Identity?

• Composite of many elements:
  • Career, political, religious, relational, sexual, cultural, personal, and physical

Erikson’s Theory

• Identity vs. Identity Confusion (adolescence)
  • Successful resolution → identity achievement
  • Failure leads to:
    • Identity confusion (incoherent self)
    • Foreclosure (adopting others' values without exploration)
    • Negative identity (opposing others’ expectations)

James Marcia’s Identity Statuses:

Influences on Identity Formation:

• Parenting style (e.g., authoritarian → foreclosure)
• Behavior (e.g., substance use disrupts identity development)
• Social context (e.g., SES limits opportunities)
• Historical era (e.g., shifts in gender role expectations)

Gender Development

Gender vs. Biological Sex

• Sex: Biological assignment at birth
• Gender: Socially constructed roles and expectations

Nature vs. Nurture (Case Study: David Reimer)

• Reassignment of gender identity failed → biological factors matter

Biological Theories

1. Evolutionary Approach
   • Gender differences helped survival:
     • Men: aggression, impulsivity → hunting/mating success
     • Women: alliances, nurturing → childcare success
   • Gendered stress responses:
     • Males: “fight or flight”
     • Females: “tend and befriend”
   • Play behavior: Boys → rough play; Girls → caregiving roles
2. Neuroscience Approach
   • Hormones like androgens (e.g., testosterone) shape behavior
   • Example: CAH girls show more “boy-like” interests and play
   • Organizational vs. Activational effects:
     • Organizational: prenatal or pubertal hormone-driven brain development
     • Activational: hormone-triggered behaviors later on (e.g., oxytocin release)

Cognitive Theories of Gender

Kohlberg’s Stages of Gender Understanding:

Gender Schema Theory

• Children build mental schemas of gender roles.
• Classify others as ingroup (same gender) or outgroup.
• Tend to explore “own-gender” behaviors and ignore opposite-gender ones.

Gender Socialization

At Home:

• Parents assign chores based on gender:
  • Boys: outdoor, tool-based
  • Girls: caregiving, indoor
• Gender-essentialist talk: reinforces stereotypes (e.g., commenting more on girls' appearance)

Media & Gender

• TV shows overrepresent male characters and reinforce stereotypes.
• These portrayals influence children’s development of gender norms.

Gender Roles in Adolescence

Sexual Orientation & Identity

• Defined as preference for male or female romantic/sexual partners
• Central to adolescent identity

Coming Out Process:

1. First recognition – Feeling different
2. Test/exploration – Contact with other LGBTQ+ individuals
3. Identity acceptance – Preference for same