StellarPiaget's Stages
According to Piaget, children develop schemas via continuous and discontinuous processes such as assimilation and accommodation (see 2.2 for the definitions). Sensorimotor stage (infancy through toddlerhood): infants learn through senses and motor activity. Object permanence, the understanding that objects continue to exist when out of sight, develops during this stage. Before object permanence develops, peek-a-boo seems magical. Preoperational stage (toddlerhood through early childhood): children become proficient in using mental symbols and engage in pretend play. The preoperational stage is identified more by cognitive tasks children cannot perform such as conservation (understanding that quantity doesn't change with shape) and reversibility, or by those they exhibit, such as animism (attributing feelings to inanimate objects) and egocentrism (inability to see another's perspective). Children begin to develop a theory of mind (understanding that others have different beliefs, desires, and intentions) during this stage. Concrete operational stage (early through late childhood): children can generally correct the cognitive errors made in the preoperational stage and understand the world in logical, realistic, and straightforward ways, but struggle to think systematically about abstract concepts. Formal operational stage (late childhood through adulthood): people in this stage gain the ability to think abstractly and hypothetically. Piaget proposed that not all people achieve formal operational thinking, and indeed not all tasks evoke formal thought even in adults.