Why are we so afraid of clowns? If you ask my sister, it's because a clown once popped a balloon in her face. His name was Macaroni, and he used to entertain families at a diner near where we grew up, and she was so afraid of him that if we were eating there, and she realized it was a Tuesday night (aka Family Night), she would burst into tears. And she's not alone. During the craziness of the 2016 election, the country was gripped by creepy-clown fever, with sightings of sinister roadside clowns reported all across America.

Professor Andrew McConnell Stott credits the scary clown to Charles Dickens, who edited the memoirs of a real-life British jester named Grimaldi. Dickens explicitly tied the many tragedies of Grimaldi's life -- alcoholism, poverty, chronic pain -- to his willingness to debase himself for an audience. Ever since, Stott told Smithsonian Magazine, we've...