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.).