Why you should care
Because being wrong has never been so right.
Most people wouldn’t recognize Zoe Bell’s name, or even her face — though both have graced their fair share of gigantic screens. Uma Thurman, however? No problem picking out those distinctive features in a crowd. Well, Bell serves as Thurman’s stunt double, and, until recently, scientists weren’t sure why we could so gullibly watch ass-kicking Bell in a fight scene and “see” the trained actress Thurman. According to research out of UC Berkeley’s neuroscience department, published in Current Biology:
We see the face we expect to see because of a brain mechanism that helps images look stable and continuous.
Study participants were asked to find a match to a projected face on a computer screen. Consistently, they chose a face that was not a match to the previous one but was instead a mixture, or composite, of the faces they’d seen the previous few seconds. “If we didn’t see the same face, then the world would look really chaotic,” first author on the study Alina Liberman says.
Basically, we evolved to be wrong about a stunt double’s identity. Our minds assume continuity to save us from searching the faces of our loved ones every time they turn or change their hair. On the flip side, there is prosopagnosia, or face blindness, a condition that makes it difficult for people to keep track of faces from moment to moment, putting them at a disadvantage when building relationships and trying to sustain them.
Plus, the brain saves a lot of energy by trusting that the visual environment is continuous moment to moment. Brains are always trading off energy between paying attention to “new things that are potentially hazardous” and things that are “likely to stay the same,” Liberman says.
Of course, it’s also movie magic that helps in the case of the stunt double. Stunt doubles are chosen who are as close as possible to the actor’s weight, height, facial structure and more. Plus, president of the Stuntwomen’s Association of Motion Pictures Katie Rowe says that when doubles fall, “we tend to throw our arms up and cover our faces or turn our faces away.” Or sometimes, the filmmakers do a “cowboy switch,” Rowe says. Two actors will fight until a big stunt, and the filming will pause to put the stunt double in to take that big punch or fall. In postproduction, the seams are hidden and continuity is maintained.
What’s amazing is that recognizing faces is a strength in human beings “better,” Liberman says, “than any other visual skill out there.” Still, we can get it wrong. Luckily, that makes for better movies and a saner, less anxiety-filled living experience.