Michael Graziano | The Atlantic
To understand the expressive range of the human face, nothing beats watching a colleague scream his head off in slow motion. When my lab began to study protective reflexes in the early 2000s, the video cameras came out and the place became a scare factory. Graduate students took to lurking in hidden corners and lunging out with Velociraptor shrieks. Sundry plastic bugs and a pair of taxidermized monkey arms found their way inside the lunch refrigerator. I confess, I once took a cow eyeball from a dissection class, wrapped it in foil, and gave it to a colleague as a chocolate truffle.
By filming the reactions and reviewing the videos frame by frame, we began to realize that the startle reflex might be an evolutionary point of origin for many of our most common human emotional expressions.