Flare-ups over cultural appropriation have become such a routine part of our cultural dialogue that we could practically play Mad Libs with them. This week’s fill-in-the-blanks controversy: A Utah teenager wore a vintage cheongsam to her prom and is now being excoriated by certain denizens of the Internet for an act of alleged cultural theft. We’ve been through so many of these imbroglios that it’s probably easy to figure out which side you think you’re on. But it’s worth considering what arguments about cultural appropriation, cultural evolution and cultural exchange should accomplish — and whether the dialogues we’re having over and over again are actually helping us get there.