Swiss Psychologist Jean Piaget (1896-1980) proposed the idea of the four stages of childhood cognitive development. These are age-related stages and refer to certain accomplishments that should be achieved, by the child, at the end of each stage.
The first stage of cognitive development is the Sensorimotor stage, which lasts from birth to around two years of age. During this stage, children learn to coordinate their senses (hearing, sight, touch etc.) with their motor abilities. From two to seven years is the Pre-operational stage. …