A well-known child psychologist, Jean Piaget, described four stages of cognitive development in children. His theories are based on how a child understands new information and adjusts his or her thinking to accommodate the new information.
From birth to about the age of two, children go through a sensorimotor stage in which an infant is trying to make sense of the worlds. During this stage, learning takes place by means of motor activities and sensory perceptions. Stimuli to senses cause simple motor reactions in children. Children discover that they are separate from the environment even though it exists outside the reaches of the senses. To learn about the environment, children use skills and abilities such as sucking, grasping, looking and listening.
The next stage of development occurs between the ages of two and six and is marked by the development of language. Children can now represent objects and personify them using symbols. Children are oriented to the present but can now better think about things that are not in their immediate environment. Children cannot yet conceptualize time but are able to role play and speak.
Between the ages of six to early adolescence is the concrete operational stage. During this stage, children’s mental operations improve and accommodation increases. Children can think logically about concrete events but understanding abstract or hypothetical concepts poses some difficulty. Their logic is based on inductive reasoning, going from specific to general principles, and they understand the principle of reversibility.
The final stage which occurs in adolescence and lasts until adulthood is the formal operations stage. Children are now able to think about and understand abstract concepts and are capable of hypothetical and deductive reasoning. Whereas in earlier stages, problem solving was accomplished by the trial and error method, children in this stage are now able to solve problems in a logical methodical approach.