Carlyon said clowns were considered sweet and funny for two centuries until an inevitable backlash that included Stephen King’s hit novel “It,” the film “Poltergeist,” Heath Ledger’s white-faced maniac Joker, the misanthrope Krusty the Clown from “The Simpsons,” the shock band Insane Clown Posse and Homey D. Clown from “In Living Color.”

“Anything that gets that much glorification and is sentimentalized within an inch of its life invites someone to snark at it,” said Carlyon, who recently discovered the cover of a National Lampoon from 1979 with a girl cowering in fear of a malevolent clown.

“There’s nothing in any available evidence that kids were afraid of clowns in the ’40s, the ’50s, the ’60s, the ’70s,” he said. “Who said that about Red Skelton?”