Short answers, pulled from the story.
Dark humor is a style of comedy that makes light of subject matter generally considered taboo, especially subjects normally treated as serious or painful. It aims to provoke discomfort, serious thought, and amusement in its audience at the same time.
The Surrealist theorist André Breton coined the term black humor, from the French humour noir, in 1935 while interpreting the writings of Jonathan Swift. He used it in his 1940 book Anthology of Black Humor, crediting Swift as the originator of black humor and gallows humor.
Dark humor is a relatively broad term covering humor about many serious subjects, while gallows humor is used more specifically for death or situations reminiscent of dying. Dark humor also differs from blue comedy, which focuses on nudity, sex, and body fluids, and from plain obscenity.
Saint Lawrence became the patron saint of comedians because he made a dark joke during his own execution. Sentenced to be burned alive on a rotisserie, he is said to have quipped, "Turn me over. I'm done on this side," which also made him the patron saint of chefs.
Bruce Jay Friedman's 1965 paperback Black Humor labeled authors such as J. P. Donleavy, Edward Albee, Joseph Heller, Thomas Pynchon, John Barth, Vladimir Nabokov, and Louis-Ferdinand Céline as black humorists. Later critics added Roald Dahl, Kurt Vonnegut, Warren Zevon, Christopher Durang, Philip Roth, and Veikko Huovinen.
Police officers, firefighters, ambulance crews, military personnel, journalists, lawyers, and funeral directors use dark humor as an acknowledged coping mechanism because their work routinely involves dark subject matter. Workers are encouraged to note the context, since outsiders may not react the way those with mutual knowledge do.
A 2017 study published in the journal Cognitive Processing concluded that people who appreciate dark humor may have higher IQs, show lower aggression, and resist negative feelings more effectively than people who dislike it.