John McWhorter in the New York Times:
Justice Ruth Bader Ginsburg grew up with a solid old-school Brooklyn accent. She displays no trace of it in recordings of her work as a young litigator, but today, one can hear shades of it in her speech on and off the court. Why?
Black English is often reviled as an indication of lower intelligence, and yet ever more, advertisers seek out voice-over artists with an identifiably “Black” sound. Why?
Things like this do not surprise linguists who specialize in the intersection of language and sociology. For example, they have found that people of the lower middle class, in settings where their speech is being evaluated, tend to speak more “correctly” than even upper-middle-class or wealthy people do. Justice Ginsburg’s suppression of Brooklyn vowels was a perfect example, as is the fact that having moved into a different class since, she subconsciously feels she has less to “prove.”
Meanwhile, the Black English issue can best be explained through an experiment carried out in Montreal in the 1960s at a time when English was considered much more prestigious than French.