I dunno, Tom, a Culture of Violence is usually the first thing that comes to mind when the I think about Chicago.When I think of southern culture the first people who come to mind are Robert Johnson, BB King, Al Green, Little Richard, James Brown and those who made it up to Chicago like Muddy Waters, Howlin' Wolf, Willie Dixon and Buddy Guy.
And Elvis. And Steve Cropper.
I think courtesy in white southern culture springs from a culture of violence and seems a product compulsion rather than consideration. I think the common passive-aggressive behavior also springs from an undercurrent of violence.