From M3GAN, to Chucky, to Annabelle; Haunted or ‘scary’ dolls has been a trope explored numerous times. Here’s why this trope can rake in the cash so often.

Our minds have a broad way of recognizing things as human and an acute way of recognizing when something isn’t quite right. Mannequins, dolls, and CGI people explore this idea in the most direct sense. Each of them look human-like and can even move human-like but not exactly. It’s difficult to replicate a living organism with something made from plastic or pixels. So when our minds expect plastic or pixels to move a certain way and they don’t, alarms go off in our heads. We get creeped out and maybe even disgusted because these things don’t quite function like we expect. This trigger is known as the ‘uncanny valley’ effect.

Ayse Saygin, a cognitive scientist at the University of California, explains the effect: “If you look human-like but your motion is jerky or you can’t make proper eye contact, [the uncanny valley takes effect]. I think the key is that when you make appearances humanlike, you raise expectations for the brain. When those expectations are not met… you have the problem in the brain.”

First coined in 1970 by Japanese robotosist, Masahiro Mori; The Uncanny Valley effect is described as that point where your brain distrusts what you’re looking at, whether doll, mannequin, or CGI. There’s a rise of trust as your brain recognizes the figure as being human and then there’s that sharp decrease when you recognize otherwise. When drawn on a chart you can see the ‘valley’ created. Evolution has triggered our brain to signal something is wrong when someone looks off. Some people believe the trigger exists to identify people who may have a contagious disease or have mental or physical issues that could become a problem in the evolutionary chain.

We have a natural fear of dolls due to the uncanny valley, but it’s also the fact that we expect them to start moving and talking at any moment. But they don’t (Hopefully). That build of suspense around them puts us on our toes and makes us naturally uneasy. On top of the Uncanny Valley effect, there’s obviously the haunted possession portion of the story. A possessed doll is less natural than a non-possessed doll, so obviously a viewer would be a bit more wary of a haunted doll such as Chucky or Anabelle. The possession can make the dolls move in an uncanny-like way and usually makes the doll violent- At least in good doll movies. Combine anything with blunt violence and blood, and the audience will have a different take on something than if they were watching something with sunshine and rainbows. 

Whether it’s the horror or the fascination, there’s no question that killer dolls are a classic trope that will continue to evolve with humanity, just like M3GAN being the new, futuristic Chucky.