Psychology

The most commonly used theory in the cognitive development of children was developed by Jean Piaget. According to Piagets theory of cognitive development, children grow through specific stages as their intelligence and ability to connect things mature. These stages occur in order in all children around the world. Range of age at which the stages occur can vary from one child to the next (Child development institute, 2000). The chart below summarizes the four basic stages of Piagets cognitive development.

Source Wagner (2008).
The first stage in a childs development is the sensorimotor stage which occurs between the time of birth and 2 years of age. At this time, the infants start understanding the information they are given and begin to interact with their surrounding. At this age bracket, the child learns how to manipulate objects except that they do not understand existence of these objects once they are removed from their sight.  The most important development at this stage is the continued existence of the objects. If a child has achieved the object permanency, heshe will know that if the mother leaves the room she will return and this increases their sense of safety and security. Object permanency develops towards the end of this stage and shows the childs capability to retain a mental image of an object even when they are removed from their site (Thomas, 2009).

The second stage of development starts immediately after the achievement of object permanency. The stage is between the ages of two to seven years and is referred to as preoperational stage. Language development occurs very fast during this stage. The interaction with the environment at this stage is complicated and is enhanced through the use of words and images. At this stage, the child has a belief that everyone thinks at the same level with them. They cannot see the difference in perception between themselves and other people and thinks that even non living things also have perceptions similar to theirs (Sigelman  Rider, 2005).

The other characteristic of this stage is conservation. Children at this stage fail to understand that the quantity of a substance does not change with change in its shape. They would always go for longer objects thinking that they are bigger than the other object which is plumb and has the same quantity. This occurs because they do not appreciate reversibility and concentrates on one aspect like height as opposed to the width of objects (Gwen, 2009).

The third stage of a childs development is concrete operational stage. It occurs between the ages 7 and 12 and the main distinguishing feature of this stage is the ability of the child to focus on more than one aspect of the stimulus. Children at this stage are able to appreciate the idea of grouping. The concepts understood can be used in concrete objects they have encountered before. Things which they have never seen appear to them as mystery since abstract thinking has not developed (Child Development Institute, 2000).

Formal operational stage is the final stage of cognitive development. It starts at the age of 12 and proceed into adulthood. During this stage, abstract thinking starts to develop. The concepts of reversibility and conservation can be applied to both real and imagined situations. Children at this stage begin to understand the world better and the idea of cause and effect. When they reach their teens, they are in a position to develop their theories about the world. Most children attain this stage except those with low intelligence (Wagner, 2008).