Foundations Of Cognitive Science


In Piaget's theory of development, there are two cognitive processes that are crucial for progressing from stage to stage: assimilation, accommodation. These two concepts are described below.


This refers to the way in which a child transforms new information so that it makes sense within their existing knowledge base. That is, a child tries to understand new knowledge in terms of their existing knowledge. For example, a baby who is given a new object may grasp or suck on that object in the same way that he or she grasped or sucked other objects.


This happens when a child changes his or her cognitive structure in an attempt to understand new information. For example, the child learns to grasp a new object in a different way, or learns that the new object should not be sucked. In that way, the child has adapted his or her way of thinking to a new experience.

Taken together, assimilation and accommodation make up adaptation, which refers to the child's ability to adapt to his or her environment.


  1. Siegler, R. (1991). Children's thinking. Englewood Cliffs, NJ: Prentice-Hall.
  2. Vasta, R., Haith, M. M., & Miller, S. A. (1995). Child psychology: The modern science. New York, NY: Wiley.

(Revised October 2009)