I've read this before, in my twenties, and I've just re-read the title story. Flannery O'Connor's very good and the characters in the story are recognisable even though they come from a long distant past: the mother who is a real old-school southern racist, born and raised, and her son who thinks of himself as better than her but his rejection of her racism is driven entirely by spite.
Also takes a prize for one of the best names of a short story ever.