How do we study developmental change? The visual cliff Responses to looming Habituation and Dishabituation methods Preferential looking technique Robert Fantz (1961)

Developmental Psychology: …the study of how psychological processes change over time. It focuses on the changes that occur in people’s abilities and behaviours as they grow older.

Newborns’ Visual Preferences 5 10 15 20 25 30 35 Total fixation time (%)

How do we develop cognitively? Stage-like vs continuous development Piaget’s stage theory (1896–1980) Criticisms of Piaget’s stage theory Vygotsky’s theory of continuous development (1896-1934)

How do we develop cognitively? stage-like continuous development

Criteria for stage-like development: 1. Ordered periods 2. Qualitative changes 3. Rapid transitions 4. Completion of each stage before the next.

Piaget’s Stages of Cognitive Development Approx. Age range Developmental milestones Stage 0 to 2 years Sensorimotor Object permanence Stranger anxiety 2 to 7 years Preoperational Ability to pretend Egocentrism 3-mountain task Conservation

focusing on certain aspects loosing sight of others Concretism: inability to extract the “abstractness” of something Irreversibility: of thought and actions Centration: focusing on certain aspects loosing sight of others

Piaget’s Stages of Cognitive Development (continued…) Approx. Age range Stage Developmental milestones Concrete operational Mathematical transformations 7 to 11 years Hypothetico-deductive reasoning Scientific reasoning Potential for mature moral reasoning 11 to adulthood Formal operational

Lev Vygotsky’s theory of continuous development internalization zone of proximal development (ZPD) (a.k.a.: zone of potential development) static-assessment environment dynamic-assessment environment