Lifespan Development – Key Vocabulary

Lifespan Development Overview

• Lifespan development = study of how people change and stay the same from conception to death.

• Encompasses three inter-related domains:

  • Physical – growth of body/brain, sensory & motor systems, health.

  • Cognitive – learning, memory, language, reasoning, creativity.

  • Psychosocial – emotions, personality, relationships.

• Normative approach: establishes developmental milestones (e.g., crawling, walking \approx 12\text{ mos}, puberty \approx 11{-}14\text{ yrs}).

  • Biological milestones = universal; social milestones vary by culture (e.g., school entry).

Core Developmental Debates

• Continuous vs. Discontinuous

  • Continuous = gradual accumulation (e.g., height adds inches yearly).

  • Discontinuous = stage-like leaps with qualitatively new abilities.

• One Course vs. Many Courses

  • Stage theorists argue for a universal sequence (e.g., language milestones worldwide).

  • Cross-cultural evidence: caregiving practices alter timing (milestones may accelerate/slow).

• Nature vs. Nurture

  • Nature = genetics/biology; Nurture = environment/culture.

  • Twin/adoption studies explore relative contribution (e.g., IQ resemblance, personality differences among siblings).

  • Consensus: both interact continuously.

Major Theories of Development

• Freud’s Psychosexual Theory (discontinuous, childhood-focused)

  • Five stages: Oral, Anal, Phallic, Latency, Genital.

  • Fixation possible if needs unmet → adult personality quirks (e.g., oral fixation in smokers).

• Erikson’s Psychosocial Theory (lifespan-wide, social focus)

  • Eight tasks; mastery → competence, failure → crisis.

  1. Trust vs. Mistrust (0{-}1 yrs): meet basic needs.

  2. Autonomy vs. Shame/Doubt (1{-}3 yrs): self-rule.

  3. Initiative vs. Guilt (3{-}6 yrs): purposeful action.

  4. Industry vs. Inferiority (7{-}11 yrs): competence @ tasks/school.

  5. Identity vs. Role Confusion (12{-}18 yrs): personal identity.

  6. Intimacy vs. Isolation (19{-}29 yrs): close relationships.

  7. Generativity vs. Stagnation (30{-}64 yrs): societal/family contributions.

  8. Integrity vs. Despair (65+): life review.

• Piaget’s Cognitive Theory

  • Children build schemata; adapt via assimilation (fit new info) and accommodation (alter schema).

  • Stages:
    • Sensorimotor (0{-}2): object permanence, stranger anxiety.
    • Preoperational (2{-}6): symbolic thought, egocentrism, pretend play.
    • Concrete Operational (7{-}11): logical reasoning, conservation, math.
    • Formal Operational (12+): abstract, hypothetical, moral reasoning.

• Kohlberg’s Moral Development

  • Three levels (each with 2 sub-stages):
    • Pre-conventional – obedience, self-interest.
    • Conventional – conformity, law-and-order.
    • Post-conventional – social contract, universal ethics.

Prenatal Development

• Germinal Stage (\text{Week }1{-}2)

  • Fertilization → zygote → rapid mitosis; implantation at \approx 150 cells.

• Embryonic Stage (\text{Week }3{-}8)

  • Organogenesis; heartbeat begins; placenta/umbilical cord supply nourishment.

• Fetal Stage (\text{Week }9{-}40)

  • Growth + brain maturation until full term.

• Teratogens: alcohol (FAS), smoking, drugs, radiation, HIV, herpes, rubella.

  • Fetal-Alcohol Syndrome markers: small head, facial anomalies, ↓ IQ, poor impulse control.

  • Prenatal care critical for monitoring mother & fetus.

Infancy (Birth–2 yrs)

Physical

• Rapid growth first 2 yrs.

• Newborn reflexes: rooting, sucking, grasping, Moro.

• Sensation: vision least mature; prefer maternal voice & smell.

• Brain: blooming (thousands of new synapses), then pruning.

  • Brain size 55\% of adult at 2 yrs; 90\% at 6 yrs.

• Motor: gross → fine progression; cephalocaudal & proximodistal trends.

Cognitive

• Object permanence emerges \approx 8 mos (earlier than Piaget claimed—Baillargeon’s study).

• Milestones: shake head “no” ( 6{-}9 mos ); follow verbal requests ( 9{-}12 mos ).

Psychosocial

• Attachment

  • Harlow’s monkeys → comfort > food.

  • Bowlby: secure base; all-or-nothing bond; caregiver responsiveness vital.

  • Ainsworth’s Strange Situation → styles:

  1. Secure – explores, distressed on separation, comforted on return.

  2. Avoidant – indifferent, slow positive response.

  3. Resistant – clingy → angry, difficult soothe.

  4. Disorganized – bizarre behaviors; linked to abuse.

Early & Middle Childhood (2{-}11 yrs)

Physical

• Growth slows 4{-}6 yrs; girls’ spurt starts 8/9, peaks \approx 12.

• Fine motor (pencil grip) & gross motor (running/balance) refine.

Cognitive

• 3{-}5 yrs: counting, colors, name/age, time sequencing, symbolic play, endless “why?” → developing theory of mind.

• 6{-}11 yrs: logical/organized thought, cause–effect, math, limited attention until \approx 11.

Psychosocial

• Self-concept: mirror recognition 18 mos; photo self-recognition 24{-}46 mos.

• Age 2{-}4: gender labels, cooperative play.

• Age 4: sharing/cooperation; task initiation.

• Age 6: identify with groups.

• Parenting Styles (Baumrind):

  • Authoritative (warm + rules) → best outcomes.

  • Authoritarian (strict, low warmth) → obedience, lower social competence.

  • Permissive (few demands) → poor self-regulation.

  • Uninvolved (neglect) → worst outcomes.

• Temperament moderates parenting–outcome link (Easy vs. Difficult).

Adolescence (12{-}18/19 yrs)

Physical

• Puberty: adrenarche + gonadarche.

  • Menarche \approx 12{-}13 yrs; spermarche \approx 13{-}14 yrs.

  • Secondary sex traits (breasts, voice, facial hair).

  • Growth spurt: girls finish by 16, boys by 17.

• Brain: frontal lobe not fully myelinated until early 20\text{s} → risk-taking, emotional swings.

Cognitive

• Formal operational reasoning; multiple hypotheses.

• Increased processing speed OR capacity (debated).

• Cognitive empathy rises → better conflict resolution.

Psychosocial

• Erikson: Identity vs. Role Confusion.

• Peers become primary influence; may adopt parental or peer values.

• Positive parent bonds → ↑ grades, ↓ behavior problems.

Emerging Adulthood ( 18 – mid 20\text{s} )

• Recently recognized (Western). Prolonged exploration of love & work.

• Contributing factors: longer lifespan, higher education requirements, cultural value on self-exploration.

Adulthood

Physical

• Early (20\text{s}{-}40\text{s}): peak strength, speed, senses.

• Middle (40\text{s}{-}60\text{s}): gradual decline (elasticity, vision, weight gain, menopause, graying).

• Late (60+): slower reaction, muscle loss, sensory decline; mitigated by exercise & lifestyle.

Cognitive

• Crystallized intelligence (knowledge/skills) stable or increases.

• Fluid intelligence (processing, memory) declines.

• Mental stimulation (games, reading) delays decline.

Psychosocial

• Work: satisfaction when tasks involve people, interest, advancement, autonomy.

• Relationships: stable marriage & children enhance well-being (despite early stress).

• Socioemotional selectivity theory: older adults keep fewer but deeper relationships.

Death & Dying

• Cultural/religious practices vary (burial, cremation at sea, Hindu rites).

• Kubler-Ross 5 Stages of Grief: Denial → Anger → Bargaining → Depression → Acceptance.

• Individual & cultural differences influence experience of dying and mourning.