LONDON—Findings released Monday by Britain's Home Office indicate that politeness among Londoners has dipped 2 percent since the July public-transit bombings. "Terrorist bombers? Well, I say—good day to them—a tip of my hat to them, indeed, and may they take their leave of our green and pleasant land," said Andrew Capper of Surbiton. "Far be it from me to pass judgment, as I've never met the chaps myself—and goodness knows I'm not without error—but I should think that a few of these terrorists have behaved in a manner that can only be described as rather less than gentlemanly, if I do say so myself, may it please you, good sir." The Home Office cites post-traumatic stress in the sharp decline in manners, the worst since the 4 percent drop during the Blitz of 1940.