Okay great, that's EASILY operatinalizable. Set up -say- 100 replications of the same question sequence (say to build a program) against some cheap model like qwen. One half of the set can be with please and thank you, and the other half without. You can vibe code it even. I'd be curious to see your results!
You can even boost its effectiveness by roleplaying with it. I’m not joking. Fully based on vibes, I haven’t done any testing. But it’s part of prompting imo.
IMO these things are like a reflection. Present what you want reflected back.