Assimilation is a term used in various fields to describe the process of becoming part of a group, society, or culture. Here are some key points from the search results:

• Anthropology and Sociology: In these fields, assimilation refers to the process whereby individuals or groups of differing ethnic heritage are absorbed into the dominant culture of a society. The process of assimilating involves taking on the traits of the dominant culture to such a degree that the assimilating group becomes socially indistinguishable from other members of the society. As such, assimilation is the most extreme form of acculturation.

• Psychology: In psychology, assimilation is a learning process that involves incorporating new information into existing knowledge structures. This process can occur at each stage of cognitive development and is complementary to the process of accommodation, which involves modifying existing knowledge structures to fit new information.

• Linguistics: In linguistics, assimilation refers to a sound change in which a sound becomes more similar to a neighboring sound. For example, the "s" sound in "his shoe" is often assimilated to a "sh" sound.

• Social Behavior: Assimilation is one of the four major categories of social behavior, according to Robert E. Park and Ernest W. Burgess. It is "a process of interpenetration and fusion in which persons and groups acquire the memories, sentiments and attitudes of other persons or groups, and by sharing their experience and history are incorporated with them in a common cultural life".

In summary, assimilation can refer to the process of becoming part of a dominant culture, the process of incorporating new information into existing knowledge structures, a sound change in linguistics, or a category of social behavior.