Piaget- just the basics please
Piaget's theory is based in developmental psychology. As such, there are a number of rules that are generally applied that help one to understand the concepts being dealt with. These include:
Stages are QUALITATIVELY different: Developmental stages are considered to be different, not just in the quantity of what a child can do, but in significant qualitative ways as well. Therefore, a child who adds new words to his/her vocabulary is not in a new stage- because only the quantity has changed. But a child who can begin to use pronouns appropriately may be siad to have entered a new stage of language development.
Effected by both environment and genetics: For years psychologists have debated the influence of nurture (environment) and nature (genetics) on the develoing child. Piaget (trained as a biologist) was influenced strongly by the way that all organisms adapt to their environment. This adaptation shapes behavior as well as genes, just like genes and behavior shape adaptation. He believed the same was true for hu,man behavior. Therefore, in Piaget's model it is not nature or nurture but nature and nurture.
Development follows a prescribed sequence: All human development conforms to certain rules and can be predicted based upon these rules. The sequence is the same for all individuals, and stages cannot be skipped.
Development cannot go backwards: Once achieved, a stage cannot be lost or forgotten. In Piaget's terms, this means that once an individual has acquired operational thinking, they will always have operational thinking. This does not include cognitive changes that are brought on by trauma, neurologic disorders, or other impairments that are atypical developmental processes.
Development is relatively orderly: There is a pattern to development that can be discerned and that has adaptational value for the species.
Development occurs at different rates: While general guidelines can be determined, there are no specific and invariant time frames associated with human development. Unlike ducks, we cannot identify a specific day of life on which the infant becomes attached to a parent. Rather, we can identify various periods in time during which attachment is likely to occur.
Development takes place gradually: When a child is acquiring a new cognitive strategy, such as the ability to seriate (sort by size), the child will likely be able to accurately seriate on some occassions but not others. Similarly, the child may an accurate job of sorting up to 4 straws of varying lengths, but fail when a fifth is introduced. However, over time, the ability solidifies and an be observed in all situations.