normally will not behave politely u

normally will not behave politely unless there is a reason to be polite (even if the reason is somewhat vague, such as following convention). They can also be impolite (see 8.2, in Chapter 8): for example, a member of the concert audience could have booed, hissed, or sat in stony silence when the time for applause arrived. In the case of concert performances, this seems to be rare in English-speaking societies, even when the performance is poor—but it cannot be ruled out. Politeness is generally thought to be a good thing, and socialization of children includes learning to be polite. However, there are occasions where rude-ness or impoliteness is felt to be desirable—where the recipient of impolite behavior “had it coming to them.”
A second point about politeness is that there are varying gradations of polite and impolite behavior. This can be illustrated in a highly conventionalized form in our example of the violin performance. A bow is a gesture of lowering one-self physically, and hence socially—and the deeper the bow, the more self-lowering and polite it is deemed to be.

The clapping and cheering, on the other hand, is a response signaling appreciation or high evaluation of someone’s performance—and the louder and the more prolonged the clapping is, the greater the appreciation signaled and the more polite the response.
Third, notice, further, that there is often a sense of what is normal, recognized by members of society, as to how polite to be for a particular occasion. If, after a thrilling and dexterous piece of playing, the violinist received only two perfunctory rounds of applause, lapsing into silence as soon as she left the platform, this would be felt to be less polite than normal. In fact, English has an idiom to capture under polite compliments: “damning with faint praise.” On the other hand, if the audience continued its rapturous applause for ten minutes, repeatedly cheering on the soloist’s return to view, this would be considered exceptional if not excessive—a case of over politeness.
Fourth, how far politeness will occur, or whether it will occur at all, depends on the situation. Just suppose we are no longer in a concert hall, but in a foot-ball stadium. The footballer who scores a goal, instead of bowing meekly, is likely to execute some kind of war-dance, signaling his delight and self-congratulation. Instead of meekness, he shows exultation: “Wow! I am the greatest!” The crowd cheer him, but the cheers could have quickly changed to jeers and boos if he had committed a fatal error and deprived his team of victory. The difference between this and the concert is that the one occasion is almost a kind of ritualized war-fare, whereas the other is not. Similarly, there are activity types where impoliteness dominates over politeness, and indeed part of the rationale of those activity types is that they encourage discourtesy. Examples where rudeness is generally more salient than politeness are:
• The leader of the opposition questioning the prime minister at “Question Time” in the British House of Commons
• Certain “reality” TV shows, where contestants are routinely humiliated or are shown being subjected to verbal abuse
• Training recruits in an army boot camp
• Interrogation of a prisoner of war or a crime suspect ¤ Hostile cross-examination in a court of law
• Heckling a speaker at a political meeting
There are also situation types where impolite behavior breaks out sporadically, even though it is widely disapproved of; for example, in the UK there has been public disquiet about abusive members of the public using rude and aggressive language in addressing health professionals and other public servants.