During the first few years of life, children undergo a rapid period of cognitive development, taking them from an extremely primitive state of function to one in which they begin to understand complex concepts. The developmental psychologist Jean Piaget classified this development into two major stages: sensorimotor and preoperational, the latter of which comprised four substages. The Piagetan model is one way caregivers can evaluate a child's development and identify any delays or challenges.
Sensorimotor Stage
The earliest stage of cognitive development is the sensorimotor stage. Children develop and utilize motor skills, but their intellectual development is restricted almost entirely to sensory input. In this stage, children understand little that is not occurring directly to them, and anything that passes from their direct, immediate experience loses its importance. A ball that rolls out of sight ceases to exist. Children usually grow out of this stage by two years of age.
Symbols
The first part of the preoperational stage involves the development of symbolic thinking. Here, children can retain symbolic knowledge of an item or person even when it is not in their line of sight. A child can remember extended family members, or realize that a favorite toy is missing and look for it. This stage usually occurs between two and four years of age.
Language
Another stage in the preoperational phase of cognitive development is the growth and use of language. Young children begin to understand language, but early on can only grasp literal meanings. Older children learn to interpret the spoken word and can understand the intent behind what they hear. A child late in this stage could interpret the phrase, "I'd like to give you some cereal, but I don't see your bowl," as a request to get their bowl, where a younger child would have to be told directly. Children between three and six years old experience this stage of development.
Intuition
The intuitive stage of development marks the beginning of non-magical thinking in children. Young children, when asked how something happened, often come up with completely nonsensical answers. As children begin to develop cognitively, the ability to reason comes into play, as does their understanding of the steps involved in a process. A young child might believe that food just appears in the kitchen cabinets and refrigerator, while an older child would understand that parents must go to the store and purchase groceries. This stage encompasses children between four and seven years of age.
Information Processing
As children grow older, they develop the ability to process and order information, an important skill in the preschool and early school years. An example of information processing is a child adding on her fingers; she understands the relation between counting fingers and counting abstract numbers, and that she can use her fingers to find the solution to an addition problem. Children enter this stage of development between the ages of five and seven.
