According to psychologist Jean Piaget, children progress through a series of four critical stages of cognitive development. Each stage is marked by shifts in how kids understand the world. Piaget believed that children are like "little scientists" and that they actively try to explore and make sense of the world around them.
Through his observations of his children, Piaget developed a stage theory of intellectual development that included four distinct stages:
- The sensorimotor stage, from birth to age 2
- The preoperational stage, from age 2 to about age 7
- The concrete operational stage, from age 7 to 11
- The formal operational stage, which begins in adolescence and spans into adulthood.
Jean Piaget's Background
Jean Piaget was born in Switzerland in 1896. He published his first scientific paper at the tender age of 10 – a 100-word description of an albino sparrow in a naturalist magazine. Between the ages of 15 and 19 he published numerous papers on mollusks and was even offered a job as a curator at a museum, although he had to decline the offer since he still had two years of high school to complete.
While he developed an interest early on in how people come to know the world around them, he didn't receive any formal training in psychology until after he had completed his doctoral degree at the University of Neuchatel. After receiving his Ph.D. degree at age 22 in natural history, Piaget formally began a career that would have a profound impact on both psychology and education. After studying briefly with Carl Jung, he happened to meet Theodore Simon, one of Alfred Binet's collaborators.
Simon offered Piaget a position supervising the standardization of the intelligence tests developed by Binet and Simon.
Piaget developed an interest in the intellectual development of children. Based on his observations, he concluded that children were not less intelligent than adults, they simply think differently. Albert Einstein called Piaget's discovery "so simple only a genius could have thought of it."
Piaget's stage theory describes the cognitive development of children. Cognitive development involves changes in cognitive process and abilities. In Piaget's view, early cognitive development involves processes based upon actions and later progresses to changes in mental operations.
Piaget's interest in child cognitive development was influenced by watching his 13-month-old nephew, Gerard, at play. By chance, Piaget observed the toddler playing with a ball. When the ball rolled under a table where the boy could still see it, Gerard simply retrieved the ball and continued playing. When the ball rolled under a sofa out of his sight, however, the child began looking for it where he had last seen it. This reaction struck Piaget as irrational.
Piaget came to believe that children lack what he referred to as the object concept - the knowledge that objects are separate and distinct from both the individual and the individual's perception of that object.
Jean Piaget set out to study his daughter Jacqueline as she developed through infancy, toddlerhood, and childhood. He quickly noted that during the early months of his daughter's life, she seemed to believe that objects ceased to exist once they were out of her sight. At nearly a year, she started to search actively for objects that were hidden from her view although she made mistakes similar to the one Gerard made. By 21 months, Jacqueline had become skilled at finding hidden objects and understood that objects had an existence separate from her perception of them.
Piaget's observations of his nephew and daughter reinforced his budding hypothesis that children's minds were not merely smaller versions of adult minds. Instead, he proposed, intelligence is something that grows and develops through a series of stages. Older children don't just think faster than younger children, he suggested. Instead, there are both qualitative and quantitative differences between the thinking of young children versus older children.