I lived in middle-class neighborhoods all over the US when I was young (1960s and 1970s), and I don’t recall ever hearing neighbor kids using the words ‘mam’ or ‘sir’ at all.
And I have to tell you, the kids in the middle-class neighborhood I live in now, and my last neighborhood, are the nicest, polite-est, most courteous kids you could ask for. But they still don’t call me ‘sir’. 🙂
