Today, bobbing for apples is a vaguely dirty-looking (in more ways than one) but family-friendly game whose only real objective is winning a piece of fruit. Hey, why on God's flaming hot Earth do we do this?
Like most things, it began because people wanted to rub up on other people.
Hundreds of years ago, it was a game you played to flirt with your target, like pub trivia today. The floating apples were named after the young men in attendance, and the contestant furiously gulped at the apple assigned to whichever dude she was horny for. According to superstition, their chances at happiness decreased every time she missed. It was unsurprisingly popular in Britain, home of the weird expression of repression.
How did this become a game we let children play on Halloween? As you may or may not know, most modern Halloween activities come from Celtic traditions brought over by Irish immigrants in the 19th century. By that time, they were pretty much the only ones bobbing for apples, so it was just kind of mashed together with the jack-o'-lanterns and bonfires and such. Now, when you stick your head into a bucket full of every bacteria known to man for a chance at a fruit that's literally falling from trees at that exact moment, you can take pride in continuing a long, disgustingly sexy tradition.
Top image: Howard Chandler Christy/Wikimedia Commons