Goes like this: Studies show that waitresses who are extra nice to the customer get less money in tips compared to waitresses who are authoritative and don’t go out of their way to serenade. Not mean, but not overly cheery.
The university study concluded that the customer tips the bitchy waitess more than the nice waitress because it’s in our human psychology to be liked. If we are unsure, humans will “submit” in order to seek this approval. In this study, nice finishes after formal. It’s not about being nice if you want a larger tip.
A silent line draw. Your worst fear is what people think of you anyway so best get over it.