Have you ever felt like you're the only person in the movie theater not laughing?  It turns out that what we find funny is a product of our brain's ability to find incongruity between elements of the joke.  This ability differs between cultures, sexes, and age groups, but the ability to find humor in a situation is one of the things that truly makes us human, and that (obviously) is no joke.

For more insight on laughter and how we interpret jokes, check out Thumbs, Toes, and Tears at the ATH store.