The first of Piaget’s stages of cognitive development is the sensory-motor stage, which takes place from birth to 18 months. During this stage, the child changes from a newborn baby, where he or she practices innate reflexes for example, sucking and looking, to a toddler who has the ability to, at some level, think. Piaget observed that a young baby has no object permanence, which is the understanding that objects continue to exist when moved out of sight, and discovered that a baby will look where an object disappears to for a few minutes but will not search for it, and, if it fails to reappear will lose interest in it altogether. Piaget called this passive exploration. However between the ages of eight to twelve months object permanence develops. The other major progressions in this stage are self-recognition and symbolic thought for example designating words for objects. And finally deferred imitation, which is the imitation of an action which has occurred in the past, which indicates an important advance in the capacity to remember. Throughout this stage children are egocentric which means that the child can only see things from their point of view.

The second of Piaget’s stages is the pre-operational stage, which takes place between the ages of 18 months -7 years, and is divided into two sub-stages. The pre-conceptual stage, which occurs between 18moths to 4 years, and the intuitive stage which takes place between the ages of 4 to 7 years. During this stage the use of internal images, symbols and language are especially important for the child’s continuing development of a sense of self awareness, however, at the same time the child’s world is fundamentally absolute and things are very much as they seem. The nature of the pre-conceptual child’s thinking makes it difficult for it to understand relative terms such as “bigger” or “longer”, things tend to be “biggest” or “longest”. The intuitive child does have this ability but remains limited in its ability to think logically and is unable to decanter. Centration is the inability to understand more than one perceptual factor at a time. A pre-conceptual child asked to divide balls that are “big and blue” and those that red “small and red” will either put all the blue (or red) balls together or all the big (or small) balls together irrespective of their colors or sizes.