Under the influence of social psychology, especially social identity theory, communication accommodation theory are guided by mainly four assumptions.
The first assumption indicates that people bring their past experience to conversations.
There are four main socio-psychological theories: Similarity-attraction The similarity-attraction theory posits that, "The more similar our attitudes and beliefs are to those of others, the more likely it is for them to be attracted to us." An individual on the receiving end of high level of accommodation is likely to develop a greater sense of self-esteem and satisfaction than being a receiver of low accommodation.
Social exchange process The social exchange process theory "...
In fact, people can both converge at some levels and diverge through others at the same time.
People use convergence based on their perceptions of others, as well as what they are able to infer about them and their backgrounds.
When two people who speak different languages try to have a conversation, the language they agree to communicate with is more likely to be the one used by the higher status person.
This idea of "salient social membership" negotiation is well illustrated in the situation of an interview as the interviewee usually makes all efforts to identify with the interviewer by accommodating the way he speaks and behaves so that he can have more chance to secure the job.
However, when this same behavior was attributed to pressures in the situation forcing the other to converge, positive feelings were not so strongly evoked." Intergroup distinctiveness The process of intergroup distinctiveness, as theorized by Tajfel argues, "...
Communication accommodation theory (CAT) is a theory of communication developed by Howard Giles.
This theory concerns "(1) the behavioral changes that people make to attune their communication to their partner, and (2) the extent to which people perceive their partner as appropriately attuning to them." "Communication accommodation theorists focus on the patterns of convergence and divergence of communication behaviors, particularly as they relate to people’s goals for social approval, communication efficiency, and identity"Particularly, it focused on the cognitive and affective processes underlying individuals' convergence and divergence through speech.
The last assumption puts emphasis on social appropriateness and norms. expectations of behaviors that individuals feel should or should not occur in a conversation".
Those expectations give guidance to people's behaviors, helping them to figure out the appropriate way to accommodate.