Comment by wahern

In rural Georgia my father's wife, still 15+ years my senior, would always "yessir" and "no sir" me, just as she did with everyone else (ma'am for women, of course). And this was in the past 10 years. Even my half-siblings from rural Alabama do that generally, but not nearly so strictly with family like myself. Use of last names, though, is still reserved for non-family elders.

Conversely, in coastal California that kind of speech is actively (even aggressively) discouraged, such as in public schools, higher grades, especially. It's still appreciated in more traditional communities, though, such as black or immigrant Asian communities. Code switching isn't limited to certain minority groups; even affluent coastal white folks often end of code switching.