Piagets theory of cognitive development

The Theory of Cognitive Development, one of the most historically influential theories was developed by Jean Piaget, a Swiss psychologist (1896–1980). His theory provided many central concepts in the field of developmental psychology and concerned the growth of intelligence, which for Piaget, meant the ability to more accurately represent the world and perform logical operations on representations of concepts grounded in the world. The theory concerns the emergence and acquisition of schemata—schemes of how one perceives the world—in "developmental stages", times when children are acquiring new ways of mentally representing information. The theory is considered "constructivist", meaning that, unlike nativist theories (which describe cognitive development as the unfolding of innate knowledge and abilities) or empiricist theories (which describe cognitive development as the gradual acquisition of knowledge through experience), it asserts that we construct our cognitive abilities through self-motivated action in the world. For his development of the theory, Piaget was awarded the Erasmus Prize. Piaget divided schemes that children use to understand the world through four main periods, roughly correlated with and becoming increasingly sophisticated with age:
 * Sensorimotor period (years 0–2)
 * Preoperational period (years 2–7)
 * Concrete operational period (years 7–11)
 * Formal operational period (years 11–adulthood)

Sensorimotor period
Infants are born with a set of congenital reflexes, according to Piaget, in addition to a drive to explore their world. Their initial schemas are formed through differentiation of the congenital reflexes The sensorimotor period is the first of the four periods. According to Piaget, this stage marks the development of essential spatial abilities and understanding of the world in six sub-stages:
 * 1) The first sub-stage, known as the reflex schema stage, occurs from birth to six weeks and is associated primarily with the development of reflexes.
 * 2) The second sub-stage, primary circular reaction phase, occurs from six weeks to four months and is associated primarily with the development of habits.
 * 3) The third sub-stage, the secondary circular reactions phase, occurs from four to nine months and is associated primarily with the development of coordination between vision and prehension.
 * 4) The fourth sub-stage, called the co-ordination of secondary circular reactions stage, which occurs from nine to twelve months, is when Piaget (1954) thought that object permanence developed.
 * 5) The fifth sub-stage, the tertiary circular reactions phase, occurs from twelve to eighteen months and is associated primarily with the discovery of new means to meet goals.
 * 6) The sixth sub-stage, considered "beginnings of symbolic representation", is associated primarily with the beginnings of insight, or true creativity.

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 new kind of psychological functioning occurs.

(Pre)Operatory Thought in Piagetian theory is any procedure for mentally acting on objects. The hallmark of the preoperational stage is sparse and logically inadequate mental operations. During this stage the child learns to use and to represent objects by images and words, in other words they learn to use symbolic thinking. Thinking is still egocentric: The child has difficulty taking the viewpoint of others.

The child can classify objects by a single feature: e.g. groups together all the red blocks regardless    of shape or all the square blocks regardless of color. According to Piaget, the Pre-Operational stage of development follows the Sensorimotor stage and occurs between 2–7 years of age. In this stage, children develop their language skills. They begin representing things with words and images. However, they still use intuitive rather than logical reasoning. At the beginning of this stage, they tend to be egocentric, that is, they are not aware that other people do not think, know and perceive the same as them. Children have highly imaginative minds at this time and actually assign emotions to inanimate objects. The theory of mind is also critical to this stage. (Psychology 8th Edition, David Myers)

The Preoperational Stage can be further broken down into the Preconceptual Stage and the Intuitive Stage

The Preconceptual stage (2-4 years) is marked by egocentric thinking and animistic thought. A child who displays animistic thought tends to assign living attributes to inanimate objects, for example that a glass would feel pain if it were broken.

The Intuitive(4-7 years) stage is when children start employing mental activities to solve problems and obtain goals but they are unaware of how they came to their conclusions. For example a child is shown 7 dogs and 3 cats and asked if there are more dogs then cats. The child would respond positively. However when asked if there are more dogs then animals the child would once again respond positively. Such fundamental errors in logic show the transition between intuitiveness in solving problems and true logical reasoning acquired in later years.

(Child Psychology, 1st Canadian Edition, Hetherington, Parke & Schmuckler)

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, occurs between the ages of 6 and 12 years and is characterized by the appropriate use of logic. Important processes during this stage are:

Seriation—the ability to sort objects in an order according to size, shape, or any other characteristic. For example, if given different-shaded objects they may make a color 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 alive and therefore have feelings).

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 if 4+4 equals 8, 8−4 will equal 4, 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 transferred to a pitcher it will conserve the quantity and be equal to the other filled cup.

Elimination of Egocentrism—the ability to view things from another's perspective (even if they think incorrectly). For instance, show a child a comic in which Jane puts a doll under a box, leaves the room, and then Melissa moves the doll to a drawer, and Jane comes back. A child in the concrete operations stage will say that Jane will still think it's under the box even though the child knows it is in the drawer.

Formal operational stage
The formal operational period is the fourth and final of the periods of cognitive development in Piaget's theory. This stage, which follows the Concrete Operational stage, commences at around 11 years of age (puberty) and continues into adulthood. It is characterized by acquisition of the ability to think abstractly, reason logically and draw conclusions from the information available. During this stage the young adult is able to understand such things as love, "shades of gray", logical proofs, and values. Lucidly, biological factors may be traced to this stage as it occurs during puberty (the time at which another period of neural pruning occurs), marking the entry to adulthood in Physiology, cognition, moral judgement (Kohlberg), Psychosexual development (Freud), and social development (Erikson). Some two-thirds of people do not develop this form of reasoning fully enough that it becomes their normal mode for cognition, and so they remain, even as adults, concrete operational thinkers.

General information regarding the stages
These four stages have been found to have the following characteristics:


 * Although the timing may vary, the sequence of the stages does not.
 * Universal (not culturally specific)
 * Generalizable: the representational and logical operations available to the child should extend to all kinds of concepts and content knowledge
 * Stages are logically organized wholes
 * Hierarchical nature of stage sequences (each successive stage incorporates elements of previous stages, but is more differentiated and integrated)
 * Stages represent qualitative differences in modes of thinking, not merely quantitative differences

Challenges to Piagetian stage theory
Piagetians accounts of development have been challenged on several grounds. First, as Piaget himself noted, development does not always progress in the smooth manner his theory seems to predict. 'Decalage', or unpredicted gaps in the developmental progression, suggest that the stage model is at best a useful approximation. More broadly, Piaget's theory is 'domain general', predicting that cognitive maturation occurs concurrently across different domains of knowledge (such as mathematics, logic, understanding of physics, of language, etc). However, more recent cognitive developmentalists have been much influenced by trends in cognitive science away from domain generality and towards domain specificity or modularity of mind, under which different cognitive faculties may be largely independent of one another and thus develop according to quite different time-tables. In this vein, many current cognitive developmentalists argue that rather than being domain general learners, children come equipped with domain specific theories, sometimes referred to as 'core knowledge', which allows them to break into learning within that domain. For example, even young infants appear to understand some basic principles of physics (e.g. that one object cannot pass through another) and human intention (e.g. that a hand repeatedly reaching for an object has that object, not just a particular path of motion, as its goal). These basic assumptions may be the building block out of which more elaborate knowledge is constructed.

Post Piagetian and Neo-Piagetian stages
There are three major changes to the number of stages and their definitions. First and foremost, the half stages are now shown to be stages. Pascual Leone discovered this. Almost all Post Piagetians accept this. Second, postformal stages have been shown to exist. Kurt Fischer suggested two, Michael Commons presents evidence for four postformal stages: the systematic, metasystematic, paradigmatic and cross paradigmatic. Fischer has considered a stage suggested by Biggs and Biggs. It is a stage before the early preoperational. Commons and Richards call this stage the sentential because organisms can sequence representations of concepts.

Piagetian and post-Piagetian stage theories/heuristics

 * Michael Barnes' stages of religious and scientific thinking
 * Michael Lamport Commons' Model of Hierarchical Complexity
 * Kieran Egan's stages of understanding
 * Suzy Gablik's stages of art history
 * Christopher Hallpike's stages of moral understanding
 * Lawrence Kohlberg's stages of moral development
 * Don Lepan's theory of the origins of modern thought and drama
 * Charles Raddings theory of the medieval intellectual development
 * R.J. Robinson's stages of history and theory of the origins of intelligence