Jean Piaget's Stages
Cognitive Development
Piaget proposed that children move through four stages of mental development.
1. Sensorimotor Stage (Birth to 2 years)
The infant knows the world through movements and sensations. Object Permanence (knowing something exists even if you can't see it) is learned here.
2. Preoperational Stage (2 to 7 years)
Children begin to think symbolically but remain egocentric (cannot see others' perspectives).
3. Concrete Operational (7 to 11)
Logical thought begins. Understanding of Conservation (water in a tall glass is the same amount as in a short glass).