Another fact about laughter: Laughing while alone

I recently wrote about how laughter can indicate one of two things: a situation that seems wrong is okay or a situation that seems okay is actually wrong. If laughter signals these two situations, you would expect it to occur mainly in the presence of other people, and it does. (Learn more about the benign violation theory HERE.)

Sometimes, however, people laugh when they are alone. Why?

When people laugh when they are alone, there is usually a person involved in some way, such as character on...