Piaget's theory of cognitive development

The theory of cognitive development is a developmental psychology theory developed by Jean Piaget to explain cognitive development. The theory is central to child psychology and is based on schemata&mdash;schemes of how one perceives the world&mdash;in "critical periods," times when children are particularly susceptible to certain information. For his development of the theory, Piaget was awarded the Erasmus Prize.

Piaget divided schemes that childen use to understand the world through four main stages, roughly correlated with and becaming increasingly sophisticated with age:
 * Sensorimotor stage
 * Preoperational stage
 * Concrete operational stage
 * Formal operational stage

Sensorimotor stage
The sensorimotor stage is the first of the four stages. According to Piaget, this stage marks the development of essential spatial abilities and understanding of the world in six sub-stages:


 * The first sub-stage occurs from birth to six weeks and is associated primarily with the development of reflexes. Three primary reflexes are described by Piaget: sucking of objects in the mouth, following moving or interesting objects with the eyes, and closing of the hand when an object makes contact with the palm (palmar grasp). Over these first six weeks of life, these reflexes begin to become voluntary actions; for example, the palmar reflex becomes intentional grasping. (Gruber and Vaneche, 1977).
 * The second sub-stage occurs from six weeks to four months and is associated primarily with the development of habits. Primary circular reactions or repeating of an action involving only ones own body begin. An example of this type of reaction would involve something like an infant repeating the motion of passing their hand before their face. Also at this phase, passive reactions, caused by classical or operant conditioning, can begin (Gruber et al., 1977).
 * The third sub-stage occurs from four to nine months and is associated primarily with the development of coordination between vision and prehension. Three new abilities occur at this stage: intentional grasping for a desired object, secondary circular reactions, and differentiations between ends and means. At this stage, infants will intentionally grasp the air in the direction of a desired object, often to the amusement of friends and family. Secondary circular reactions, or the repetition of an action involving an external object occur begin; for example, moving a switch to turn on a light repeatedly. The differentiation between means also occurs. This is perhaps one of the most important stages of a child's growth as it signifies the dawn of logic (Gruber et al., 1977). Towards the late part of this sub-stage infants begin to have a sense of object permanence, passing the A-not-B error test.
 * The fourth sub-stage occurs from nine to twelve months and is associated primarily with the development of logic and the coordination between means and ends. This is an extremely important stage of development, holding what Piaget calls the "first proper intelligence." Also, this stage marks the beginning of goal orientation, the deliberate planning of steps to meet an objective (Gruber et al. 1977).
 * The fifth sub-stage occurs from twelve to eighteen months and is associated primarily with the discovery of new means to meet goals. Piaget describes the child at this juncture as the "young scientist," conducting pseudo-experiments to discover new methods of meeting challenges (Gruber et al. 1977).
 * The sixth sub-stage is associated primarily with the beginnings of insight, or true creativity. This marks the passage into the preoperational stage.

Preoperational stage
The Preoperational stage is the second of four stages of cognitive development. By observing sequences of play, Piaget was able to demonstrate that towards the end of the second year a qualitatively quite new kind of psychological functioning occurs. Operation in Piagetian theory is any procedure for mentally acting on objects.

According to Piaget, the Sensorimotor stage of development is followed by this stage (2-7 years), which includes the following processes:

Symbolic functioning - is characterised by the use of mental symbols words or pictures which the child uses to represent something which is not physically present.

Concentration - is indicated by a child concentrating more on one aspect of a person which is consistent rather than concentrating on the inconsistent aspects of his personality, behaviour or physical characteristics.

Intuitive thought - occurs when the child is able to believe in something without knowing why she or he believes it.

Egocentrism - tendency of child to only think from own point of view.

Inability to Conserve - Through Piaget's conservation experiments (conservation of mass, volume and number) Piaget concluded that children in the preoperational stage lack perception of conservation of mass, volume, and number after the original form has changed. For example, a child in this phase will believe that a string of beads set up like this O-O-O-O-O will have the same number of beads as a string set up like OO-O-OO-O because they are the same length, or that a tall, thin 8-ounce cup has more liquid in it than a wide, fat 8-ounce cup.

Concrete Operational stage
The concrete operational stage is the third of four stages of cognitive development in Piaget's theory. This stage, which follows the Preoperational stage and occurs from the ages of 7 to 12, is characterized by the appropriate use of logic. Important processes during this stage are:

Decentering - where the child takes into account multiple aspects of a problem to solve it. For example, the child will no longer perceive an exceptionally wide but short cup to contain less than a normally-wide, taller cup.

Reversibility - where the child understands that numbers or objects can be changed, then returned to their original state. For this reason, a child will be able to rapidly determine that 4+4 which they can answer to be 8, minus 4 will equal four, the original quantity.

Conservation - understanding that quantity, length or number of items is unrelated to the arrangement or appearance of the object or items. For instance, when a child is presented with two equally-sized, full cups they will be able to discern that if water is transfered to a pitcher it will conserve the quantity and be equal to the other filled cup.

Serialisation - the ability to arrange objects in an order according to size, shape, or any other characterstic. For example, if given different-shaded objects they may make a colour gradient.

Classification - the ability to name and identify sets of objects according to appearance, size or other characteristic, including the idea that one set of objects can include another. A child is no longer subject to the illogical limitations of animism (the belief that all objects are animals and therefore have feelings).

Delimitation of Egocentrism - the ability to view things from anothers' perspective (even if they think incorrectly). For instance, shown a diagram in which Jane leaves the room knowing a doll is under the box labeled #1, the child will know that Jane will still think the doll is located under that box despite Jill moving it to under the box labeled #2.

Formal Operational stage
The formal operational stage is the fourth and final of the stages of cognitive development of Piaget's theory. This stage, which follows the Concrete Operational stage, commences at around 12 years of age (puberty) and continues into adulthood. It is characterized by acquisition of the ability to think abstractly and draw conclusions from the information available. During this stage the young adult functions in a cognitively normal manner and therefore is able to understand such things as love, "shades of gray", and values. Lucidly, biological factors may be traced to this stage as it occurs during puberty and marks the entering into adulthood in physical, cognitive, moral (Kohlberg), psychosexual (Freud), and social development (Erikson).

General Information regarding the stages
These four stages have the following characteristics:


 * 1) Although the timing may vary, the sequence of the stages does not
 * 2) Universal (not culturally specific)
 * 3) Related to cognitive development, but...
 * 4) Generalizable to other functions
 * 5) Stages are logically organized wholes
 * 6) Hierarchical nature of stage sequences (each successive stage incorporates elements of previous stages, but is more differentiated and integrated)
 * 7) Stages represent qualitative differences in modes of thinking, not merely quantitative differences

The development of thought, according to Piaget, is completed through assimilation and accommodation to existing schemas, which were first developed by Barlett, F.C. Assimilation, the representation of the concept according to a pre-existing schema, is evident when a child, seeing a horse for the first time, represents it under the quadripedal-animal schema, and calls it "doggie"; on the other hand accommodation, or the modification of an existing schema to better fit the environment, is when the child is told that this is a "horsie" rather than a "doggie".

Despite its general accuracy overall, his theory has since been slightly critiqued, because today's developmental psychologists believe the logical or cognitive development is more gradual and variable among certain groups or individuals. Many find that children combine conceptions from different developmental stages, are in different stages in different areas of life, and their advancement in thinking can be seen to vary from minute to minute. The stages are now seen as overall tendencies in thought processes; as a child develops they more frequently choose concepts from higher levels.

Further criticism of the Theory of Cognitive Development cites the inability of most adults to reach the formal operational level in all areas of life, this appearing to be largely reserved for students of tertiary education. Other critics attack the universality of the theory, claiming that the theory is only truly applicable for western society.