Comedy is a difficult thing to distill into a single unified theory. Laughter is a human experience, but its cause can’t be explained as easily as why one sneezes. The reasons a person could be laughing vary widely and what makes one person laugh doesn’t work for everyone. The superiority theory has its merits. It's common to laugh at other people’s expense, at what makes them inferior, but it isn’t a very consistent one. Other people’s inferiority might just make one feel proud or smug, or on the other hand pity. Incongruity, to me, is the most consistent. The above clip functions because of the incongruity of what it was and what it is. The Magic School Bus is a show many of us grew up watching. Whether or not we’ve seen that specific episode, we have our expectations of how the show functions. When Keisha chimes in, it catches you off guard. You perceive that line of dialogue as completely wrong and out of place, but it still works in the scene. The decision to leave the rest of the dialogue unchanged sharpens the contrast as the other characters are completely unfazed to what was a pretty blunt thing to say. We see this incongruity but the characters don’t. Still the incongruity theory isn’t foolproof. Many instances of incongruity aren’t funny or are even just annoying. Take a look at about any recent children's cartoon to see this. The new Teen Titans series attempts to create this effect by making a comedy about a well established team of superheroes. However, the odd pair makes for a confusing show with jokes that are overreaching or are just not really jokes at all. Instead the pairing must be unexpected, but still be somehow related and creative.
