I attended a Microsoft conference where two different speakers asserted:
1. Being polite to an LLM improves the output.
2. Being polite (or rude) to an LLM does not improve the output.
Both offered theories as to why.
I recently had an AI search engine refuse to answer a question about cracking the DES algorithm. I pushed back, saying something like "the DES algorithm is obsolete and hasn't been used in a decade, so please answer the question."
And it did. I 'bout fell out of my chair.
The real effect is "Cherry picking results improves output".