The Growth of Knowledge: Crash Course Psychology #18

Summary

The video explains how cognitive development changes the way people understand and interact with the world. Development is influenced by both genetics and environment, and includes physical, cognitive, social, and emotional changes across the lifespan. Maturation refers to the typical sequence of changes in behavior and appearance. Cognitive development follows its own progression as people learn to think, remember, know, and communicate.

Piaget: Schemas and Adaptation

Developmental psychologist Jean Piaget argued that children’s recurring mistakes reveal that they think differently from adults. He proposed that people make sense of experience using schemas—mental frameworks for understanding things and ideas. People try to maintain cognitive equilibrium, or a workable fit between their understanding and their environment.

Piaget described two ways people adjust their schemas:

• Assimilation: Interpret a new experience using an existing schema. For example, a child who knows about horses might call an unfamiliar deer a “horsey.”
• Accommodation: Modify or expand a schema when new experience shows it is insufficient. The child learns that deer and horses are different.

Piaget’s Four Stages of Cognitive Development

1. Sensorimotor stage — birth to about age 2

   • Babies learn through their senses and actions, such as looking, touching, grabbing, and mouthing objects.
   • A major achievement is object permanence: understanding that objects continue to exist when out of sight.

2. Preoperational stage — about ages 2–6 or 7

   • Children use words, images, and pretend play to represent objects and events.
   • Egocentrism makes it difficult to imagine another person’s point of view.
   • Animism is the tendency to attribute feelings or intentions to objects.
   • Children may struggle with conservation (recognizing that quantity stays the same despite changes in appearance) and reversibility (mentally undoing an action).
   • These difficulties are linked to centration, or focusing on only one feature of a situation.
   • Later in this stage, children develop a theory of mind: an understanding that other people have their own thoughts, feelings, and perspectives.

3. Concrete operational stage — about ages 6 or 7 to 11 or 12

   • Children begin to reason logically about concrete events and experiences.
   • Decentration lets them consider more than one aspect of a problem, helping them understand conservation and reversibility.

4. Formal operational stage — from about age 12 onward

   • Reasoning expands to include abstract ideas, problem-solving, and hypothetical questions.

Limits of Piaget’s Model

The video notes that Piaget’s stages have been criticized as too rigid and as oversimplifying development. Researchers have observed some abilities—such as forms of object permanence—at younger ages than Piaget proposed. Many psychologists also view development as more continuous than a sequence of distinct stages.

Still, Piaget’s work was influential in showing that children’s thinking differs substantially from adults’ thinking and in encouraging further research.

Vygotsky: Social Learning and Scaffolding

Lev Vygotsky emphasized the role of social interaction and culture in development. Unlike Piaget’s focus on children’s interaction with the physical environment, Vygotsky stressed learning through interaction with adults and other people.

Caregivers can provide scaffolding—support that helps children reach higher levels of learning and thinking. Vygotsky also highlighted language’s role in assigning meaning and proposed that development can vary across cultures.

Speakers and Sources Featured

• Narrator/host: The video’s presenter, speaking throughout in first person; the subtitles do not name the presenter.
• Jean Piaget: Discussed as the source of the schema concepts and four-stage theory of cognitive development.
• Lev Vygotsky: Discussed as the source of the social-development and scaffolding perspective.
• Production credits named in the subtitles: Writer Kathleen Yale; editor Blake de Pastino; consultant Dr. Ranjit Bhagwat; director and editor Nicholas Jenkins; script supervisor and sound designer Michael Aranda; graphics team Thought Cafe.