In this video, we take our first step into developmental psychology–that is, child psychology–by learning about Jean Piaget and his famous theory of cognitive development. We also discuss Renee Baillargeon's work and how the Violation of Expectation (VOE) paradigm that she pioneered challenged Piaget's theory.

Cognitive Development: How we acquire the ability to learn, think, communicate, and remember.

Jean Piaget: A famous Swiss psychologist who many call “the father of developmental psychology” because he developed the first major theory of cognitive development; a stage theorist who devised a domain-general account and who believed that learning was experience based.

Sensorimotor Stage: The first stage in Piaget’s theory of cognitive development; a stage lasting from 0 to 2 years of age in which the world is experienced through senses and actions, marked by a focus on the here and now with no thought beyond immediate physical experiences (i.e., no mental representations); children in this stage lack object permanence.

Object Permanence: The understanding the objects are permanent and continue to exist even when hidden from view.

Preoperational Stage: The second stage in Piaget’s theory of cognitive development; a stage lasting from 2 to 6 years of age in which children use words and images to represent things (i.e., mental representations), but lack logical reasoning; children are limited by egocentrism and are unable to perform what Piaget called operations.

Concrete Operational Stage: The third stage in Piaget’s theory of cognitive development; a stage lasting from 7 to 11 years of age in which children understand concrete events and analogies logically but lack abstract logic and moral reasoning abilities.

Formal Operational Stage: The fourth and final stage in Piaget’s theory of cognitive development; a stage that emerges in adolescence (at approximately 12 years of age) in which children can think abstractly and reason hypothetically.