I was born and raised down in the delta of Mississippi and was surrounded by this behavior. It’s how I am and they are the same values that I am *trying* to instill in my daughters. Making sure everyone has food and drink before you even consider getting a plate...
For men, it’s just like you say, opening doors, yes ma’aam and no ma’am. There is something to be said also for women. There’s a difference in being a woman and being a lady. (ref:Laura Bush vs. Moochelle Obama).
I live in Middle TN now and I still see it, but it’s not as prevalent. However, I have not had anyone react negatively to me for holding a door open.
I read somewhere that a guy held the door for a feminazi. She barked, "I can open it myself!"
He replied, "My apologies, I thought you were a lady."