# Stages of Development - Jean Piaget's theory - Children think of the world differently from adults. - Children need to _grasp_ something to enter next stage of development. - Vygotsky's theory. - Resources - [Piaget - Stage 2 - Preoperational - Lack of Conservation](https://www.youtube.com/watch?v=GLj0IZFLKvg) - [Biography of Jean Piaget](https://www.youtube.com/watch?v=QFNyTiNkN68) - [Piaget & Vygotsky: A Comparison!](https://www.mindmeister.com/139274374/piaget-vygotsky-a-comparison) ## Sensory Motor - Ages: Birth-2 - Learn to operate pupils, vision becomes sharper. - Infants already have memory of their mothers' voice through resonance. - Learning about objects of the world and manipulating them. - **Object Permanence** - When people/things leave, they don't seize to exist. Infants do not understand this. - Test: do they go after toys covered by blanket? ## Pre-Operational - Ages: 2-7 - Study of language, symbolic representation - Conservation test - Mistaking amount of water with height of water - Two big slices pizza vs two small slices pizza -- you both have two slices! ## Concrete Operational - Ages: 7-12 - Can understand concrete things, but not abstract one. - Ecocentrism - The world is the way they see it. - "3 Mountains" ecocentrism test, draw how the mountains would look like from the doll's point of view. ## Formal Operational - Ages: 12-15 - Pretty good at abstract concepts such as love, justice, math, etc.