Can you explain communication accommodation theory?

The socio-linguist, Howard Giles, came up with the concept of 'Communication Accomodation Theory' to demonstrate how we change our language and the way we speak depending on who we are speaking to. His theory is structured by two main functions (of language), being 'convergence' and 'divergence'.

'Convergence' means making our language more like the person's we are talking to. Giles said that convergence allows us to 'accomodate' the person we are talking to - that is to mean making them feel appreciated and valued. We can converge in many different ways: by diluting our accents, using the other person's local slang or simply speaking slower.

However, Giles also notes that language can be used to assert dominance or superiority; in these cases, we might use 'divergence'. Divergence is when we emphasise the differences in our language versus the language of person we are talking to; this might be exaggerating our accent - this is particularly relevant if your accent is one with particular prestige, like RP.