Stage theories are based on the idea that elements in systems move through a pattern of distinct s over time and that these stages can be described based on their distinguishing characteristics. Specifically, stages in cognitive development have a constant order of succession, later stages integrate the achievements of earlier stages, and each is characterized by a particular type of structure of mental processes which is specific to it. The time of appearance may vary to a certain extent depending upon environmental conditions. "Stage theory" can also be applied beyond psychology to describe phenomena more generally where multiple phases lead to an outcome. The term "stage theory" can thus be applied to various scientific, sociological and business disciplines. In these contexts, stages may not be as rigidly defined, and it is possible for individuals within the multi-stage process to revert to earlier stages or skip some stages entirely.
Jean Piaget's theory consists of four stages: Sensorimotor:, Preoperations:, Concrete operations:, and Formal Operations:. Each stage has at least two substages, usually called early and fully.
Underlying assumptions
Each stage lays the foundation for the next.
Everyone goes through the stages in the same order.
Each stage is qualitatively different. Meaning it is a change in nature, not just quantity
The child is an active learner. Basically they have to do it on their own, they cannot be told.
This stage is represented when infants obtain some control over their surroundings by sensory and motor schemes. Infants start to identify their actions and the consequences of their actions. A child comes into the world knowing almost nothing, but they have the potential that comes in the form of:
Infants use these potentials to explore and gain an understanding about themselves and the environment. They have a lack of object permanence, which means they have little or no ability to conceive things as existing outside their immediate vicinity. For example: when you place a barrier, such as a piece of wood, in front of an object an infant will believe that the object is nonexistent.
Object permanence
Study
Infants do not grasp the concept of object permanence when they do not realize that an object exists even when it is not visible at the moment.
When an object or toy is hidden from an infant they almost immediately lose interest and fail to search for the toy. This is common in infants that are eight months or younger.
Children who are around eight months can form a mental representation of an object in their head proving that they obtain object permanence
Sensorimotor play
This play does not provide a purpose other than sensation:
Swinging on a swing; enjoys the movement
Singing songs and simply playing with sounds such as 'Tra-la-la." the sound's purpose is only for the satisfaction they bring
Some play includes listening, tasting and smelling
Preoperational intelligence means the young child is capable of mental representations, but does not have a system for organizing this thinking. The child is egocentric – which is they have problems distinguishing from their own perceptions and perceptions of others. A classic example is, a preoperational child will cover their eyes so they can not see someone and think that that person can not see them either. The child also has rigid thinking, which involves the following:
Centration – a child will become completely fixed on one point, not allowing them to see the wider picture. For example, focusing only on the height of the container rather than both the height and width when determining what has the biggest volume.
State – can only concentrate on what something looks like at that time.
Appearance – focuses on how something appears rather than reality.
Lack of Reversibility – can not reverse the steps they have taken. Does not realize that one set of steps can be cancelled by another set of steps.
Lack of Conservation – realizing that something can have the same properties even if it appears differently.
Acquires ‘operations’ = a set of general rules and strategies.
The most critical part of operations is realizing ‘reversibility’ = both physical and mental processes can be reversed and cancelled out by others.
The concrete operational child will overcome the aspects of rigidity apparent in a preoperational child. These are:
lack of reversibility
states
appearance
conservation
The tasks of concrete operations are:
Seriation – putting items in height order.
Classification – the difference between two similar items such as daisies and roses.
Conservation – realising something can have same properties, even if it appears differently.
It is important to realise that operations and conservations do not develop at the same time. They develop gradually and are not an ‘all or nothing’ phenomenon. For example, the first to develop is number conservation followed by mass conservation, area conservation, liquid conservation and finally solid volume conservation. Thinking is not abstract. It is limited to concrete phenomena and the child’s own past experiences.
Formal operations (11 to 16 years)
Child is capable of formulating hypotheses and then testing them against reality.
Thinking is abstract, that is a child/adolescent can formulate all the possible outcomes before beginning the problem. They are also capable of deductive reasoning.
Limitations of Piaget's theory
A popular criticism is that Piaget underestimated the abilities of an infant. Studies have shown that they have more of a capacity in memory and understanding of objects than he believed.
Neo-Piagetian and Post-Piagetian stage theories
Juan Pascaual-Leone was the first to propose a neo-Piagetian stage theory. Since that time there have been several neo-Piagetian theories of cognitive development. Only the ones that cover at least infancy through adulthood are mentioned here. These include the theories of Robbie Case, Grame Halford, Andreas Demetriou and Kurt W. Fischer. The theory of Michael Commons' model of hierarchical complexity is also relevant. The description of stages in these theories is more elaborate and focuses on underlying mechanisms of information processing rather than on reasoning as such. In fact, development in information processing capacity is invoked to explain the development of reasoning. More stages are described, with 4 being added beyond the stage of Formal operations. Most stage sequences map onto one another. PostPiagetian stages are free of content and context and are therefore very powerful and general.
Kessen, W., & Kessel F. S., Bornstein M. H., & Sameroff A. J.. Contemporary constructions of the child: essays in honor of William Kessen. Hillsdale, NJ: L. Erlbaum Associates.
Bhattacharjee, Y.. Why bilinguals are smarter. New York Times. Retrieved from http://search.proquest.com/docview/934457002
