Modification is done then with simple facial and sound changes. Preoperational: (begins about the time the child starts to talk to about age 7)

In the Preoperational stage (again preconventional) the child is learning the symbolism and processes used for language development and accepting the existence of things which cannot be seen but can be remembered. He or she still does not completely grasp time and often thinks a bout how he or she would like things to be (the idea to make something conventional) and needs to have an active role in learning and application of his or her desires or conceptions.

Concrete: (about first grade to early adolescence)

During the concrete stage the idea of something is very literal, rather than based on ideals and/or fantasies and the individual experiences excessive need for boundaries order and rule following (conventional). He or she has not yet accepted the idea that his or her learning is flexible and can be bent to meet future needs. He or she believes and acts as if all individuals should have, know and follow the same set of rules. He or she is also capable of better conceptualizing things which are physically present and able to be touched used and felt. He or she is learning how to manipulate information through external clues.

Formal Operations: (adolescence)

Cognition, according to Piaget is completed in growth at this stage and the individual can let some concrete ideas and standards fall by the wayside (post-conventional) as he or she believes he or she sees fit to do so. The individual at this point may seek to rebel against concrete rules and standards that just a few years ago he or she believed everyone should follow. The possibilities for change are endless as he or she is capable of accepting and conceiving of many outcomes and/or possibilities to what would seem single questions.

Horowitz 41)

Though not exact the two developmental theories...

Pieget, unlike Wilbur is focused on age or at least age grouping as a general guide, where Wilbur's schemas have just as much applicability to individuals as they do to social and/or cultural groups. In each theory of development there is some application of a generalized, or requisite stage of adaptation to learning, as people become more aware of multiple options they are much more willing to reject and therefore allow conventional actions to become post-conventional. Grasping the variations of how one idea or action might impact a group that is completely separate from one's self is an aspect of both formal operations and post-conventional actions and thought. In other words, to be able to develop formal reasoning one must be able to conceive of more than the individual outcome and post-conventional standards and developments are not possible until an individual or group accepts the fact that the outcome they see, is not the whole impact of an action or standard. Both Pieget and Wilbur offer diverse perspectives to how post-conventional thought works, especially with regard to changes that are made in on a global or personal level to alter the outcome of events. For example Piaget's formal operations require and individual to understand that his or her friend has a varied perspective and is affected by his or her actions differently than him or herself, while social change as associated with post-conventional thought is applicable to adult actions in groups that are good for one group but bad for another, and how to change the later.
Works Cited

Horowitz, Frances Degen. Exploring Developmental Theories: Toward a Structural/Behavioral Model of Development. Hillsdale, NJ: Lawrence Erlbaum Associates, 1987.

Scotton, Bruce W., Allan B. Chinen, and John R. Battista, eds. Textbook of Transpersonal Psychiatry and Psychology. New York: Basic Books, 1996.