This document discusses Jean Piaget's four stages theory of cognitive development. [1] It presents Piaget's view that human intelligence develops in four stages from birth through adulthood. [2] The four stages are: the sensorimotor stage (ages 0-2 years), the preoperational stage (ages 2-7 years), the concrete operational stage (ages 7-11 years), and the formal operational stage (ages 11 years and up). [3] The document poses questions about Piaget's theory and human intelligence development.