This document describes several theories related to human development and behavior:
- Activity theory, which considers entire work systems and how distributed units are coordinated through interactions.
- Erikson's stages of psychosocial development, which describes 8 stages from infancy to late adulthood and how social and environmental factors impact personality.
- Marcia's identity statuses, which extended Erikson's model to focus on adolescent identity development and choices.
- Self-theories from Dweck, describing entity and incremental views of intelligence that shape thoughts and behavior.
- Gibson's ecological psychology, which proposes that affordances in the environment directly lead to perceived possibilities for action.