Graphic novels are book-length comic books that tell stories using images and text. They are made for audiences of all ages and often deal with serious issues and mature content beyond just being funny. For example, Art Spiegelman's MAUS took 13 years to complete and tells the story of his parents' experiences in the Holocaust by mixing fiction, non-fiction, biography, and comics formats. The Milgram experiment from the 1960s shocked Americans by suggesting that ordinary citizens were just as capable of committing atrocious acts as Germans under Nazi rule.