folkways, mores, and ethnocentrism, 1906

"Folkways, issued in 1906, brought immense popularity and fame to its author. It was composed of almost seven hundred pages of rich ethnographic detail, culled from the writings and reports of anthropologists, explorers, missionaries, and travelers. Although Folkways eventually passed into intellectual obsolescence, when Maslow read it in the 1920s it was still the definitive work on cultural variability, introducing concepts such as folkways, mores, and ethnocentrism into scientific and even popular language.
[William Graham] Sumner wrote the book partly to clarify his notion that humans have held tremendously variable beliefs and customs over the course of world history and civilization. Each culture's members tend to view its own mores as correct, proper, or even divinely commanded, and to dismiss differing perspectives as wrong, crazy, or evil. To dramatize his thesis, he selected practices abhorrent to modern sensibility, such as infanticide and child sacrifice, incest, cannibalism, slavery, blood revenge, and witchcraft, each of which was deemed normal and indeed moral by its own culture."

-- The Right to Be Human: A Biography of Abraham Maslow, Edward Hoffman, 1988, p. 30.