One of the most well known theories in cognitive development is Piaget 's theory. The psychologist Jean Piaget theorized that as children 's minds development, they pass through distinct stages marked by transitions in understanding followed by stability. Piaget describes four different stages of development: sensorimotor, preoperational, concrete operation, and formal operations. Each stage describes the thinking patterns of a child depending on his or her age. In order to compare the thinking processes of a three-year old and a nine-year old using Piaget 's theory, you must compare two sequential stages of cognitive development: preoperational and concrete operations. At three years old, Piaget argues a child is in the preoperational stage, which lasts from ages two to seven and is characterized by an ability to create mental representations of experience. During this stage, children may use objects, drawings, and language to show their ideas. Children …show more content…
Unlike a three-year old in the preocupational stage, a nine-year old is no longer inhibited by an egocentric point of view. A nine-year old can also easily pass conservation tasks. At age nine, Piaget describes that children excel at jobs which involve organization and solving problems bases on physically tangible or visible objects. For instance, a class of nine-year olds would be able to organize themselves from tallest to shortest quite quickly, or arrange their desks into various shapes. However, children in the preocupational phase still struggle with solving problems that have to do with things that are not tangible or visible. For example, Piaget would say that a child in this stage would have difficulty thinking about abstract math concepts, such as those involved in