What are Piaget’s stages of cognitive development and what characterizes each stage?

Piaget's Stages of Cognitive Development

Jean Piaget, a Swiss psychologist, proposed that children progress through four universal stages of cognitive development. Each stage is characterized by distinct ways of thinking and understanding the world.

1. Sensorimotor Stage (Birth to ~2 years)

• Infants learn through sensory experiences and manipulating objects.
• Key characteristic: Object permanence-the understanding that objects continue to exist even when out of sight.

2. Preoperational Stage (~2 to 7 years)

• Children begin to use language and think symbolically.
• Key characteristics: Egocentrism (difficulty seeing perspectives other than their own), animism (attributing life to inanimate objects), and lack of conservation (not understanding that quantity remains the same despite changes in shape).

3. Concrete Operational Stage (~7 to 11 years)

• Children start thinking logically about concrete events.
• Key characteristics: Mastery of conservation, classification, and seriation (ordering objects).
• Thinking is still tied to concrete, tangible concepts.

4. Formal Operational Stage (12 years and up)

• Adolescents develop abstract and hypothetical reasoning.
• Key characteristics: Ability to think about abstract concepts, systematically solve problems, and use deductive logic.

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Worked Example: Conservation Task

A classic test of the concrete operational stage is the conservation of liquid task.

Scenario:
A child is shown two identical glasses, each with the same amount of water:

$$ \text{Glass A:} \quad boxed{\text{Water level}} $$
$$ \text{Glass B:} \quad boxed{\text{Water level}} $$

The water from Glass B is poured into a taller, thinner glass (Glass C):

$$ \text{Glass C:} \quad boxed{\text{Taller, same water}} $$

Question:
Does Glass C have more, less, or the same amount of water as Glass A?

• Preoperational child: "Glass C has more because it's taller."
• Concrete operational child: "They have the same amount; the water was just poured into a different glass."

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Takeaways

• Piaget identified four stages: sensorimotor, preoperational, concrete operational, and formal operational.
• Each stage reflects qualitatively different ways of thinking.
• Mastery of conservation marks the transition from preoperational to concrete operational thinking.