Freud, Erikson, Piaget; learning & cognitive theories; relational models.

Nature vs. nurture; continuity vs. discontinuity; stability vs. change; critical/sensitive periods

Developmental psychologists divide the human lifespan into distinct age-related periods 1. Prenatal Development Begins at conception and ends with birth — rapid biological change.

1. Infancy and Toddlerhood Birth to about 2–3 years — major physical, motor, and sensory development.

2. Early Childhood (Preschool Years) About ages 2–6 — language expansion, social interaction, basic self-control skills.

3. Middle Childhood About ages 6–11 — school learning, friendships, logical thinking.

4. Adolescence Typically puberty to late teens — identity exploration, abstract reasoning.

5. Early Adulthood Approximately ages 18–40 — forming intimate relationships, career establishment.

6. Middle Adulthood Approximately 40–65 — sustaining careers, parenting, physical aging signs.

7. Late Adulthood 65 and older — reflection on life, adapting to physical changes, retirement.

Some models also include emerging adulthood (18–25) and discussions of death and dying

Development is influenced by historical, cultural, economic, and social contexts (e.g., norms for aging, family structure).

Human traits can be shaped by experience and environment across life (we retain capacity for change).

Lifespan development draws from psychology, biology, sociology, anthropology, health sciences, and more.

Physical — body, brain, health, motor skills

Cognitive — thinking, memory, language

Psychosocial — emotions, relationships, personality

Development isn’t linear; people can show increases in some areas and decreases in others (e.g., better problem-solving but slower reaction time).

1. The lifespan perspective is that development is lifelong and change happens across your lifespan. No single age period is more crucial, characterized, or dominant in human development.