Howard Giles' communication accommodation theory (CAT), "seeks to explain and predict when, how, and why individuals engage in interactional adjustments with others,”[1] such as a person changing their accent to match the individual they are speaking with. Additionally, CAT studies “recipients’ inferences, attributions, and evaluations of, and responses to, them."[1] This means when speakers change their communication style, listeners are interpreting such alterations. For example, when the speaker adjusts their accent to match the listener's, the recipient may interpret this positively, perceiving it as the speaker trying to fit in, or negatively—questioning whether they are mocking them.
The basis of CAT lies in the idea that people adjust (or accommodate) their style of speech and nonverbal behavior to one another.[2] Convergence is a form of accommodation in which there are changes in the kinesics (face and body motion), haptics (touch), physical appearance, chronemics (time use), artifacts (personal objects), proxemics (personal space), oculesics (the study of eye behavior), paralanguage (vocal qualities),[3] to more similarly mirror the style of the person with whom they are speaking.[4] The concept was later applied to the field of sociolinguistics, in which linguistic accommodation or simply accommodation refers to the changes in language use and style that individuals make to reduce the social distance between themselves and others.[1][5][6]
In contrast, divergence "is a communication strategy of accentuating the differences between you and another person."[7] For example, when a native French speaker uses complex terms that a novice learner might not understand, this divergence highlights the difference in competence between the speaker and the listener.[8] By using difficult terminology, the native speaker is highlighting their proficiency while emphasizing the novice's inexperience. This creates a barrier that separates them, conveying the message, "We're not the same." Both of these are active processes that can occur either subconsciously (without the speaker recognizing what they are doing), or consciously, where the speaker intentionally makes these nonverbal and verbal adjustments.
The body of CAT is full of "Accommodative norms, competences, resources, and energies are fundamental characteristics of social interaction and communication in social media and those involving other new technologies, allowing the individuals and groups involved to manage variable conversational goals, identities, and power differentials between and among themselves."[1]
"During the 1970s, social psychologists Giles, Taylor, and Bourhis laid the foundations of what was then named speech accommodation theory (SAT) out of dissatisfaction with socio-linguistics and its descriptive (rather than explanatory) appraisal of linguistic variation in social contexts, as well as to provide the burgeoning study of language attitudes with more theoretical bite".[9] The speech accommodation theory was developed to demonstrate all of the value of social psychological concepts to understanding the dynamics of speech.[10] It sought to explain "... the motivations underlying certain shifts in people's speech styles during social encounters and some of the social consequences arising from them."[9] Particularly, it focused on the cognitive and affective processes underlying individuals' convergence and divergence through speech. The communication accommodation theory has broadened this theory to include not only speech but also the "non-verbal and discursive dimensions of social interaction".[10] CAT has also created a different perspective from other research in language and social interaction—and communication more generally—that focuses on either interpersonal or intergroup communication.[11]