Costumes and trick-or-treating
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.
Tricks and games
These days, the "trick" part of the phrase "trick or treat" is mostly an empty threat, but pranks have long been a part of the holiday.
By the late 1800s, the tradition of playing tricks on Halloween was well established. In the United States and Canada, the pranks included tipping over outhouses, opening farmers' gates and egging houses. But by the 1920s and '30s, the celebrations more closely resembled an unruly block party, and the acts of vandalism got more serious.
Trick or Treat! Children utilize problem solving, planning, and thinking skills to find the shortest path to retrieve items. Collect treats from neighbors and then go back home. The goal is to plan the shortest path between points and to return home before the pumpkin.