As technology improves and entertainment media such as movies and video games are able to more closely approximate realism, humanoid characters get dangerously close to what Mori described. For example, take a look at some of the most negative reviews that the motion picture The Polar Express received. The film attempted to create a highly realistic look through computer-generated imagery (CGI), but missed a few key points, such as the depiction of the characters' eyes and skin, which made them seem more doll-like than human, causing an involuntary repulsion among viewers.
Chris Bregler, Associate Professor of Computer Science at NYU's Courant Institute and director of the NYU Movement Lab, says “When you do animation, there are reverse kinematics – a bit like a puppet.” In other words, the force is externally applied rather than being an intrinsic component of the character’s physicality. This was perfectly fine with the aliens in Avatar, Bregler illustrates, but if the same performance was applied to people, the illusion would have dissolved."
The uncanny valley is also evident in motion capture as applied to virtual actors, such as the animated characters in Final Fantasy which have achieved astounding realism as stationary images – but all familiarity is lost once there’s facial movement. Due to technological limitations, body and face motion capture cannot reproduce subtle small-scale movements that communicate essential real-world information. Without these present, viewers immediately enter the uncanny valley.
The actual “valley” refers to a precipitous drop in “likeability” as onscreen characters and humanoid robots step too far towards being human-like. As in, we enjoy Pixar’s Wall-E and Nintendo’s Mario, but we get the heeby jeebies from the ultra-realistic faces of The Polar Express or the upcoming Tintin movie.
Mitt Romney is the storybook presidential candidate. He's successful, good-looking and a family man, to boot. Yet one of this political season's enduring puzzles has been the former governor's consistent inability to bond with voters. It's been suggested that Romney's robotic persona may be to blame -- and perhaps the analogy isn't far off. Much as people are repulsed and disturbed by automatons that mimic humans closely but imperfectly, Romney inexplicably turns voters off despite looking like the textbook image of an American president.
As comic-book theorist Scott McCloud points out, we identify more deeply with simply drawn cartoon characters, like those in Peanuts, than with more realistic ones. Charlie Brown doesn't trigger our obsession with the missing details the way a not-quite-photorealistic character does, so we project ourselves onto him more easily. That's part of the genius behind modernist artists such as Picasso or Matisse. They realized that the best way to capture the essence of a person or object was with a single, broad-stroked detail.
When an android, such as R2-D2 or C-3PO, barely looks human, we cut it a lot of slack. It seems cute. We don't care that it's only 50 percent humanlike. But when a robot becomes 99 percent lifelike—so close that it's almost real—we focus on the missing 1 percent. We notice the slightly slack skin, the absence of a truly human glitter in the eyes. The once-cute robot now looks like an animated corpse.
According to all of the roboticists and computer scientists we interviewed, the uncanny is in short supply during face-to-face contact with robots. Two of the robots that inspire the most terror—and accompanying YouTube comments—are Osaka University's CB2, a child-like, gray-skinned robot, and KOBIAN, Waseda University's hyper-expressive humanoid. In person, no one rejected the robots.
In a 1970 paper in the journal Energy, roboticist Masahiro Mori proposed that a robot that's too human-like can veer into unsettling territory, tripping the same psychological alarms associated with a dead or unhealthy human.
Mori (1970) proposed a curve to
show the relationship between peoples' positive responses to an object and the humanness
of that object. He suggested that as human-like features increase, people respond
more positively to the object. However, at a distinct point, the curve dramatically dips
into the `uncanny valley', a region where the deviations from humanness are stronger
than the reminders of humanness, so a feeling of uncanniness overcomes familiarity, and
people respond with repulsion.