Scientists think they’ve figured out the “uncanny valley” – why humanoid robots creep us out

July 15, 2011 By Jeffrey Van Camp

Researchers from the university of California, San Diego, have discovered that a mismatch between movement and humanoid traits could be causing the uncanny valley effect, or the uneasiness we feel when we look at humanoid robots or CGI creations.

The uncanny valley is a theory that attempts to explain the feeling of uneasiness or creepiness we’ve all experienced when we see a video game, movie, or robot that looks extremely human. Video games, movies, and robotics are continually present us with creations that look more and more human-like. Have you ever seen The Polar Express or Final Fantasy: The Spirits Within? Or perhaps you’ve played one of the many hyper-realistic video games out today or seen creepy Japanese androids. It’s often endearing when we see things act human, like the toys in Toy Story or R2D2, but the more human they look, the harder it is to not notice and get creeped out by the small ways they are not human. This uneasiness, or unlikability, is amplified with movement.

The phenomenon has often been explained using the graph below, which shows that there’s a point when our brain stops seeing something as a cute creation that mimics humanity and starts instead counting out its flaws and making us feel mighty unpleasant.

Scientists now believe they’ve figured out what causes the uncanny valley response. Researchers at the University of California, San Diego, used an MRI to scan the brains of 20 people as they were shown 12 videos of a hyper-realistic android robot doing things like waving, nodding, drinking water, and picking up a piece of paper, reports Science Daily. Then they were shown those same actions performed by a human that looked identical to the android (many androids are built in the image of their creator, it seems). Finally, the subjects watched that same android perform the tasks again, but this time without any of the fake skin or eyes–meaning the androids looked a lot less human and more robotic.

The results suggests that the uneasiness we feel could be caused by a “perceptual mismatch between appearance and motion.” Basically, the brain seemed to negatively react like crazy when the robotic motions of the android didn’t match its human-like appearance.

“The brain doesn’t seem tuned to care about either biological appearance or biological motion per se,” said Saygin, an assistant professor of cognitive science at UC San Diego. “What it seems to be doing is looking for its expectations to be met — for appearance and motion to be congruent.”

Unfortunately, we still don’t entirely know why our brain hates this inconsistency, but if movies and video games are any indication, our brains may be able to get used to the oddness of our human-like creations in time. Games like L.A. Noire have found success by somewhat reducing the uncanny valley effect by drastically improving the facial and body animation of its characters. Faster animation in motion-capture CGI films like the upcoming Spielberg film The Adventures of Tintin are also working around this odd phenomenon. Unfortunately, we don’t quite know if our brains will ever truly accept fake humanoids until they are completely indistinguishable from ourselves.

Have you experienced the uncanny valley? Does it not bother you anymore? Has it never bothered you?

Showing 5 comments

J.s. Garrison at 4:50pm 28th July 2011 Bother me? No. I get fascinated in learning how closely the robots function in comparison to humans as time progresses.I see the imperfections in balance, movement, reaction and interaction and I know instantly whether I'm watching human or robot.I study the overall design and watch to see what mechanisms are used to emulate human-like motion and facial movements.We're close. Not enough to fool anyone or create a real uncanny valley sense in me; although I like the idea and evolution of robots and I'm not likely ever to develop an affliction to them being too human-like.
TheLast Psychiatrist at 10:10pm 27th July 2011 Where the uncanny valley theory goes wrong is in assuming that what makes us horrified is the deviation from authentic human. But uncanny has nothing to do with appearance, but is something that was supposed to remain secret but has been revealed. That secret “thing” or experience doesn’t come from the robot, it comes from you, and you’re not supposed to ever see it. Making it more visible only makes it worse.It may be possible to build a robot that can trick a human for a time; but if the human knows that it is a robot, that knowledge alone invokes the dread.
Clint Johnson at 5:37am 27th July 2011 The stilted movements are often indicative of extreme illness if exhibited by a real person so the uncanny valley is an evolved behavior that avoids a contagion vector.
tangocharlie at 12:09am 27th July 2011 I see a hole in this assertion. If one watches an animation (or really good robotics) where the motion is more human-like than the appearance, this uneasiness is [usually] not triggered (for instance Toy Story). That would tend to disprove the assertion that the two must correlate. Rather, it would seem more accurate to say that the brain wants the degree of human-like motion to be as-good-or-better than the degree of human-like appearance.
1. jgalt at 9:18am 28th July 2011 First, how do you know the uneasiness is not triggered in the situation you give? Have you studied it? Or are you saying it's not triggered for you? It's entirely possible that most people would feel uneasy in that situation, even if you don't.Second, Toy Story is not a good test case. Are you saying the movements in Toy Story actually look human? They don't. They may exhibit a lot of human emotion (much like Wall-E), but they do not look like true, human movements. So while the motions in Toy Story are closer to human than the characters' appearance is, your brain still easily recognizes what you're looking at to be non-human.The whole point here is that the "androids" used in the study look extremely human-like. This makes the brain expect natural, human motions from them. When they don't deliver, it freaks us out. And maybe when a thing moves like a living creature, but doesn't look like one, that, too, freaks us out. Take a look at this: http://bigdogrobotvideos.com/ That's clearly not human (or dog) in appearance, but it is a wee bit creepy.