Lifespan Development Summary

Definition & Domains

• Lifespan development: study of change + stability across life.
• Three core domains:
  • Physical: growth, brain, motor, health.
  • Cognitive: learning, memory, language, reasoning, creativity.
  • Psychosocial: emotion, personality, social ties.

Key Debates

• Continuous (gradual) vs. Discontinuous (stage-based) change.
• One universal course vs. multiple culturally conditioned courses.
• Nature (genes) vs. Nurture (environment); twin/adoption work shows interaction.

Major Theories

• Psychosexual (Freud): five erogenous stages; early fixation shapes adult traits.
• Psychosocial (Erikson): eight lifespan crises; mastering each → competence.
  • Trust vs Mistrust 0-1 yrs
  • Autonomy vs Shame/Doubt 1-3
  • Initiative vs Guilt 3-6
  • Industry vs Inferiority 7-11
  • Identity vs Role Confusion 12-18
  • Intimacy vs Isolation 19-29
  • Generativity vs Stagnation 30-64
  • Integrity vs Despair 65+
• Cognitive (Piaget): schema-driven stages
  • Sensorimotor 0-2: object permanence.
  • Pre-operational 2-6: symbols, egocentrism.
  • Concrete 7-11: logic, conservation.
  • Formal 12+: abstract thought.
• Moral (Kohlberg): three levels—pre-, conventional, post-conventional reasoning.

Prenatal Development

• Germinal (weeks 1-2): zygote, mitosis, implantation.
• Embryonic (weeks 3-8): organogenesis, heartbeat, placenta.
• Fetal (weeks 9-40): growth & brain maturation.
• Teratogens (alcohol, smoking, drugs, radiation, viruses) → defects (e.g., fetal-alcohol syndrome).

Infancy & Childhood

Physical

• Rapid growth then slows by 4-6 yrs; neural blooming → pruning.
• Motor sequence predictable; fine vs. gross skills.

Cognitive

• Object permanence by 8 mo; milestone timeline: shake head “no” 6-9 mo, verbal response 9-12 mo, counting & symbolic play 3-5 yrs, logical thought 6-11 yrs.

Psychosocial

• Attachment: Harlow (comfort), Bowlby (secure base), Ainsworth (secure, avoidant, resistant, disorganized).
• Self-concept emerges 18 mo; social behavior & gender role play by 2-4 yrs.
• Parenting styles: authoritative (best), authoritarian, permissive, uninvolved; child temperament (easy vs. difficult) influences interactions.

Adolescence

Physical

• Puberty: adrenarche, gonadarche; menarche (~12-13), spermarche (~13-14); growth spurts, frontal-lobe maturation lags → risk taking.

Cognitive

• Formal operations, hypothetical reasoning; processing speed rises; cognitive empathy increases.

Psychosocial

• Identity vs. role confusion (Erikson); peers central; supportive parents → better outcomes.

Emerging & Early Adulthood (18-mid 20s / 20s-40s)

• Identity exploration in love & work; physical peak; crystallized & fluid intellect stable.

Middle Adulthood (40s-60s)

• Gradual physical decline (vision, skin, weight), menopause; fluid intelligence starts to drop, crystallized remains.

Late Adulthood (60s+)

• Further sensory/motor slowing; cognitive maintenance via mentally engaging activities; socioemotional selectivity: fewer but closer ties.

Work, Relationships & Well-Being

• Job satisfaction ↑ with social contact, autonomy, interest, advancement.
• Stable marriage & children linked to well-being.

Death & Dying

• Kübler-Ross grief stages: Denial → Anger → Bargaining → Depression → Acceptance.
• Cultural practices vary (burial, cremation, etc.).