I disagree with parts of the article, but I've picked out what could be of use to me and my learners.
All of us have ways of identifying someone as "arrogant", "serious", "nice", gifted with a "sense of humour" or "dull", "boring". ... The point is, we have ideological codes for distinguishing between "good" and "bad" language use. ... [for evaluating] ways of using language: on particular genres and styles, varieties, accents. ... [A] variety of English that would carry prestige in Nairobi can carry stigma in London or New York.Stressing cultural differences is rarely productive, above all as it tends to create a gap between 'us' and 'them'; and where English is concerned it also raises the issue of cultural and linguistic imperialism. But also unhelpful is simply ignoring how people use their languages, the pronunciation and tone of voice, which words/phrases are appropriate in different contexts. Exploring why differences in use exist can help learners gain a deeper insight into other cultures and develop their socio-pragmatic skills.
I've always been fascinated by the way people's body language, intonation, choice of words, and even the overall personality they give off tend to change when they switch from one language to another, or from one social group to another. Our identities, it appears, are our way of fitting in.