Dolls are creepy because your brain can't handle fake faces

And the narrative of the haunted doll certainly plays a role. But there’s a reason dolls came to be a horror trope in the first place: They reside smack dab in the middle of the “uncanny valley,” the space occupied by humanlike things that provoke a sense of unease in actual humans. The term, coined in 1970 by the Japanese robotics engineer Masahiro Mori, describes that uncomfortable middle ground between lifelike and clearly inanimate: not quite fully human, but not quite something else, either.

Pediophobia, is one branch on the larger tree of automatonophobia, or a fear of things that look like humans, like robots, wax figurines, statues. (For the record, pediophobia translates to “fear of little children,” and is linguistically just a hop and a skip away from the word for fear of actual children: pedophobia.) And dolls, like rest of the automatonophobia gang, become more fearsome the more lifelike they appear; rag dolls don’t evoke the same spookiness as a baby-size thing with real hair. As Linda Rodriguez McRobbie wrote in a history of creepy dolls for Smithsonian last year, fear of dolls wasn’t really a thing until the 19th century, when innovations in toy-making — like eyes that could open and close — meant more realistic-looking products.