The "British politeness" stereotype has real cultural foundations—though individuals vary wildly.
Aristocratic court manners (Tudor→Victorian) codified deference, indirectness, and emotional restraint. These trickled down via servant classes, boarding schools, and military discipline into middle-class norms.
On a crowded island with rigid hierarchies, politeness lubricates friction. "Please," "thank you," "sorry," queuing—these are conflict-avoidance technologies.
British English favors hedging, understatement, modal verbs ("I wonder if you might..." vs. "Give me..."). This is the grammar of politeness.
"The customer is always right" was Victorian retail gospel. Modern hospitality training reinforces performative warmth—sometimes perceived as "fake nice" by direct cultures.
Laughing at oneself disarms hierarchy, signals approachability. It's a social equalizer: "I'm not better than you; I'm just a mess like everyone."
British politeness is real, culturally engineered, and functionally useful—but not universal, not always sincere, and not uniquely virtuous. It's a social technology, not a moral superiority.