Do you think teenagers are self-absorbed? Africans are poverty-stricken? Evangelicals are judgmental? If so, how did you come to believe such a thing?

The Nigerian novelist Chimamanda Adichie, in a beautiful speech filmed for the annual TED ideas conference, speaks of the dangers of reading and believing the “single story” of a people. She tells of a childhood reading British books about characters and objects that were completely foreign to her—and consequently writing books about those same characters, even though they were merely ghosts from her dreams, because that’s what characters in literary books were supposed to be.