Horror is a genre that constantly reinvents itself, yet certain tropes have remained in place for decades. The demon-possessed doll in The Conjuring and its prequel Annabelle is part of a pantheon of scary dolls that includes Chucky from Child’s Play (1988), Talky Tina from The Twilight Zone (1963), and Hugo the ventriloquist’s dummy in Dead of Night (1945). The freaky masks worn by killers in The Purge and You’re Next have their origins in classic Universal horror villains like The Phantom of the Opera (1925) and The Invisible Man (1933). Then there’s a long tradition of scary clowns — that's Pennywise from It pictured above. So why is it that these images are just as frightening now as they were to our great-grandparents?
Clearly, there’s some deep psychology at work here. Vulture called up Harvard Medical School psychiatrist and fright-film fan Steven Schlozman — who teaches an undergraduate course on the psychology of horror — to find out why certain things stay scary.