linguistic:paraphrasing
Theories of cognitive development

Jean Piaget, a Swiss theorist, posited that children learn by actively constructing knowledge through their interactions with their physical and social environments. He suggested that the adult's role in helping the child learn was to provide appropriate materials. In his interview techniques with children that formed an empirical basis for his theories, he used something similar to Socratic questioning to get children to reveal their thinking. He argued that a principal source of development was through the child's inevitable generation of contradictions through their interactions with their physical and social worlds. The child's resolution of these contradictions led to more integrated and advanced forms of interaction, a developmental process that he called, "equilibration."

Piaget argued that intellectual development takes place through a series of stages generated through the equilibration process. Each stage consists of steps the child must master before moving to the next step. He believed that these stages are not separate from one another, but rather that each stage builds on the previous one in a continuous learning process. He proposed four stages: sensorimotor, pre-operational, concrete operational, and formal operational. Though he did not believe these stages occurred at any given age, many studies have determined when these cognitive abilities should take place.