Let's set the scene. You're livid, you want to scream at someone. But for some reason, you can't speak. What gesture do you give them? That's right - the good ol' middle finger comes immediately to mind, right? The middle finger has been known as a way to display anger for a very long time - going all the way back to ancient Greece. In fact, it's "one of the most ancient insult gestures known,” according to anthropologist Desmond Morris.