What makes trick-or-treaters happy is candy. And more candy is better, right?
Well, it turns out that might not actually be the case. A few years ago researchers did a study on Halloween night where some trick-or-treaters were given a candy bar, and others were given the candy bar and a piece of bubble gum.
Now, in any rational universe, you would imagine that the kids who got the candy bar and the bubble gum would be happier than the kids who got just the candy bar.