Straddling the line between fall and winter, plenty and paucity, life and death, Halloween is a time of celebration and superstition. It is thought to have originated with the ancient Celtic festival of Samhain, when people would light bonfires and wear costumes to ward off roaming ghosts. In the eighth century, Pope Gregory III designated November 1 as a time to honor all saints and martyrs; the holiday, All Saints’ Day, incorporated some of the traditions of Samhain. The evening before was known as All Hallows’ Eve and later Halloween. Over time, Halloween evolved into a secular, community-based event characterized by child-friendly activities such as trick-or-treating. In a number of countries around the world, as the days grow shorter and the nights get colder, people continue to usher in the winter season with gatherings, costumes and sweet treats.
The tradition of dressing in costumes and trick-or-treating may go back to the practice of "mumming" and guising, in which people would disguise themselves and go door-to-door, asking for food, Santino said. Early costumes were usually disguises, often woven out of straw, he said, and sometimes people wore costumes to perform in plays or skits.
The practice may also be related to the medieval custom of "souling" in Britain and Ireland, when poor people would knock on doors on Hallowmas (Nov. 1), asking for food in exchange for prayers for the dead.
Trick-or-treating didn't start in the United States until World War II, but American kids were known to go out on Thanksgiving and ask for food — a practice known as Thanksgiving begging, Santino said.
"Mass solicitation rituals are pretty common, and are usually associated with winter holidays," Santino said. While one tradition didn't necessarily cause the others, they were "similar and parallel," he said.