Jean Piaget (1896-1980 ... the toy still existed. Piaget found four major developmental stages (with many subdivisions). For the first year and a half or two years of life, infants are only ...

Jean Piaget's ideas ... children pass through four main stages: the sensorimotor stage, the preoperational stage, the concrete operational stage, and the formal operational stage.

Being able to represent objects in their mind is another key part of the preoperational stage and, as a result, you might see them taking part in pretend play. Image caption, According to Piaget ...