In 1970, Japanese roboticist Masahiro Mori proposed in The Uncanny Valley that the more human a robot acted or looked, the more endearing it would be to a human being. For example, most lovable Robot Buddies look humanoid, but keep quirky and artistically mechanical affectations. However, at some point, the likeness seems too strong and yet somehow, fundamentally different and it just comes across as a very strange human being. At this point, the acceptance drops suddenly, changing to a powerful negative reaction. The Uncanny Valley doesn't necessarily have to invoke fear, though; for some people, the reaction is more similar to Narm or unintentional comedy. Either way, you don't feel the same about that character as you would a human, or even something less realistic.
If shown as a graph (like the one to the right), the acceptance on the Y axis and increasing X approaching human normal, there is a slow rise, then a sudden drop, then a sudden peak as "human normal" is reached. Masahiro Mori referred to this as the "uncanny valley". This video explains it extremely well.
Thus, things that look somewhat human, but are clearly not such as C-3PO (in Star Wars) or Animated Armor produce an accepting reaction, while things that are very nearly human, but just a little strange such as a child's doll, a ventriloquist's dummy, or a clown produce a negative response. For some people, the resonance is stronger with a moving object, which is why a corpse is creepy but a moving corpse is creepier still. In fact, some people that don't have a problem with things like zombies and consider them merely another monster may still be creeped out by things like unnatural movement.
This may also apply to sound as well. For example, a voice speaking words, but at a higher or lower pitch than is humanly possible, or a recording of a human voice, but played backwards. Or maybe a computer voice like Microsoft Sam. Though, again, some people just find the effect comical and/or silly.
This trope has applied to film CGI and video-game graphics, as technology has developed over time to allow for more photorealistic graphics, but not necessarily realistic movements. It's become very easy for computers to simulate textures and skin tones, but convincing movement and facial expressions aren't so simple, often requiring Motion Capture to look realistic. More stylized 3D models or a 2D art can generally get away with odd animations or expressions, but the more realistic the graphics shoot for, the more noticeable it is when something isn't lining up with reality. This is normally a cost issue, as detailed animation can be extremely time-consuming to craft and even more so when one set of animations is used for multiple characters and still needs to look natural for all of them. Not putting in enough effort can produce the effect where a character can come across as something less than human, like a zombie. As computer graphics become ever more detailed and realistic, while also becoming more affordable, the Uncanny Valley becomes ever narrower, but it does not go away.
Many cartoons nowadays prefer a simultaneously stylized yet simplified character design, versus the realistic look among some older cartoons. In the latter, it's more obvious the budget just didn't allow characters to move much. Heavily 3D模拟器rotoscoped characters also often seem less real than more stylized animated characters, especially when they're in the same production. See the Fleischer Studios version of Gulliver's Travels for an example.
Rather unfortunately, this trope can be applied to real-life people and may be in part an explanation (though not an excuse) for things like racism when other groups of people inspire this reaction in certain people. People with social disabilities tend to be hurt hardest by this reaction, as people usually don't try to see past the "unnatural" behaviour of the individual and may have the same negative reaction that this trope describes.
This trope can also be used on purpose, to make something creepy when creepiness is called for. Some examples of particular ways to produce this effect are listed under Creepily Long Arms, Creepy Long Fingers, Malevolent Masked Men, Undead Barefooter, Undeathly Pallor, 3D模拟器Body Horror, and Uncanny Valley Makeup. Tropes such as Everyone Hates Mimes and Monster Clown may exist because of this trope, as such characters' full-face makeup and oddball behavior can rate as invoked examples of Uncanny Valley.
A character in the valley is not necessarily doomed to being unsympathetic; sometimes they manage to be sympathetic despite evoking the unsettling uncanny valley feeling, leading to an odd kind of Narm Charm, where you find yourself crying over or rooting for a character you initially felt creeped out by due to their appearance.
See also Reality Is Unrealistic, where the poor impression comes less from being "creepy" as from breaking existing conventions which audiences had come to expect. In addition, there's Off-Model, 3D模拟器Bishōnen Line, No Flow in CGI, and Ugly Cute. And while you're at it, see What Measure Is a Non-Cute?, as the scientific study of that trope gave birth to this one. An opposite is Eldritch Abomination, where the unsettling effect is caused by being way too unfamiliar rather than being way too human, yet still produces the same abominable effect (although the two can overlap as a Humanoid Abomination). Furries Are Easier to Draw is a way artists get around the Uncanny Valley phenomenon; it's easy for drawn humans to dip into the valley, but a cartoony talking animal doesn't evoke the same response.
- If you have ever wondered why certain characters e.g Batman have the irisless white eyes in their masks, it's actually meant to invoke this. Dating back to Lee Falk the artist behind the The Phantom who claimed he was inspired to give The Phantom white eyes thanks to looking at Greek statues. Falk said there was a "inhuman" effect which suited a masked vigilante. Ironically this trend has stuck so well, that it's actually more uncanny to see the likes of Batman having normal eyes.
- The original Little Orphan Annie comics feature horrific, pure white eyes utterly empty of soul or emotion, on every character, for no apparent reason.
- The current Gasoline Alley does this in the opposite direction — every character has pure black eyes, and it's utterly unnerving.
- This happens whenever Gary Larson (The Far Side) tries to emulate the style of more serious cartoons (to parody them, usually) that they get creepy.
- The National Lampoon ran an article showcasing the 'real' people who were inspirations for newspaper comics — featuring lovingly rendered, realistic pictures of the subjects who were dead ringers for the likes of Dick Tracy, Little Orphan Annie, Popeye, and the Nightmare Fuel that was Henry.
- Audio example: Adriano Celentano's Prisencolinensinainciusol, a standard '70s funk song written by an Italian artist to sound like English. The thing is, to a native English speaker, it can be pretty disturbing, because it keeps almost sounding like English and then failing.
- The cover art of the 3D模拟器Eels' Beautiful Freak◊ album.
- Purposely invoked via makeup and image manipulation with the photos of the various characters in the liner notes for David Bowie's Rock Opera 1. Outside, as well as on the album itself with their spoken-word "segues" between songs, which are digitally tweaked to vary the voices further. It doesn't take long to realize Bowie is playing all of them, including the women; the low point of the valley here is Baby Grace Blue, the 14-year-old girl whose murder kicks off the story.
- Sparklehorse, in both the albums' artwork and the songs themselves, which often have a decaying, rummage sale-like quality that's very off, as if Linkous himself is a faulty clockwork puppet.
- Aphex Twin's Windowlicker cover◊, which is his face photoshopped onto a model's body (here's the original for anyone curious◊). If you've seen the album cover enough times to be used to it, the real thing can look like Uncanny Valley.
- The album cover for Hybrid's Wide Angle◊ has this in spades. The back is color inverted, which makes it worse.
- Daniel Amos' album Doppelgänger features photos of a department-store mannequin in the liner notes. In some of the pictures, he's wearing an eerily-realistic mask, then removes it to show that the too-human eyes are his.
- The popularity of a certain "surrealistic realism" can elicit this response from certain Italian progressive rock album covers of the early 70s. Most notable candidates: Clowns by Nuova Idea and Dedicato a Frazz by Semiramis (and its detailed inner gatefold◊) are the most prominent examples.
- The cover of South African rap duo Die Antwoord 's Ten$ion album features Yolandi Visser done up like some black-eyed, cannibalistic angel◊.
- News of the World◊ by Queen, based on the cover of Astounding Science Fiction (October 1953), features a disturbing childlike giant robot holding bloodied, dead members of the band in his hand. This was terrifying for Seth MacFarlane from Family Guy, since the B-plot of one of the episodes revolved around Brian manipulating Stewie's fear of the cover.
- The 3D模拟器pinball game White Water has a figure of Bigfoot, which (despite being designed after Dennis Nordman) looks a little... too eager to shove your balls away.
- Another pinball machine, Fun House, has Rudy, a marionette-like character whose head is on the playfield as a talking plastic model. His eyes move too and are programmed to follow the ball around. He even says "I'm watching you..." when no one is playing. That being said, it's likely that his unsettling appearance is intentional, as he's a condescending jerkass, and the game encourages you to hit him with the ball.
- The Magnus Archives invokes this in the very first episode, with what seems to be a man standing in an alley asking for a cigarette, but is in fact only a lure for something Jon calls the Angler Fish. Later episodes introduce a group of creatures posing as anatomy students so they can "learn to get the insides right," animated taxidermy humans, and "philosophical zombies" that outwardly fake humanity but have no inner mind. All of these are under the domain of The Stranger, an entity of the fear of the unknown and the creeping sense that things aren't right, most commonly in the form of things that ape the human form.
- The BBC's infamous Test Card F and its freaky clown doll.
- Bunraku puppets dance in and out of the valley. What's frightening is that they don't move like any other sort of puppet, they move exactly like little tiny people. Some of them have fairly creepy faces when seen close up◊.
- "RealDoll" sex dolls. Film technicians who have worked with Real Dolls for movies report that handling them is creepily like handling corpses. Obviously, they, their flawless sexiness and their eternal sexual submission is massive fetish appeal and/or an alternative to prostitution / free-willed women for some, thus enabling the uncanny valley to be ignored a bit. Sankaku Complex appears a disturbing amount of times here.
- Reborns. Baby dolls created to resemble the real thing as much as possible. Women also carry these things around and treat them like they're real babies. Warning: terrifying.
- The Japanese tradition/hobby/fetish of kigurumi - cosplaying human and humanoid anime characters using masks and bodysuits - seems to back into the Uncanny Valley from the human side, due to the mad creepy effect the results sometimes have.
- The mega-marionette that's made appearances at parades and festivals all over Europe has a limited head and facial animation that still manages to be creepily human in execution.
- Jeff Dunham's first puppets fell right into the valley. The ones he uses now are heavily stylized and cartoony so they don't look as unrealistic and uncanny. However, Achmed Jr. who looks more realistic and also happens to have 3D模拟器half his skin and muscle blown off falls head-first into the uncanny valley.
- Spitting Image: British satirical puppet show from the late 1980s and early 1990s featuring hundreds of grotesque caricatures of celebrities. Some very puppetlike, others moving so realistically (even with blinking eyes) that it could become creepy.
- A new fad in (where else?) Japan is "human doll cloning," which involves modeling a head from a human, printing it in 3D, and putting it on a posable doll. Results are just about exactly what you'd expect.
- Between uncanny valley and watching an episode of Friday the 13th series when he was a kid, is the reason why Channing Tatum has an admittedly bizarre fear of porcelain dolls.
- The Amazing Christopher's "Dancing Queen" routine is pretty much the Ninja Pirate Zombie Robot of Uncanny Valley horrors. It's a spin on his usual routine (the "one-man dance crew") which is usually fairly creepy as is; in this case, he's dressed up as the Red Queen from Alice in Wonderland (2010) and the dancing puppets are her card soldiers. But the cards have creepy moving mouths. And he's wearing an oversized puppet head as the Red Queen. And the puppet head has a ventriloquist dummy-like moving mouth of its own and unblinking eyes.
- Some may find the disheveled and melted mannequins in "Survival Town" Nevada as something that fits into Uncanny Valley, given that it is a whole◊ town◊ filled◊ with manikins.◊ These manikins were used during nuclear bomb tests and were supposed to represent humans in that situation.
- Disney Cruise Lines is set to feature a stage musical based on Frozen where the child versions of Elsa and Anna are to be portrayed by puppets that look like stereotypical Creepy Dolls with glassy eyes and hinged jaws, especially since they're 1:1 translations of the movie's stylized animated designs. Even worse is that it's implied that the teen versions of the sisters will be puppets as well, which is unnecessary since they can plausibly be portrayed by adult human actresses (as their adult versions are).
- Humanoid robots are very prone to this. It's much more difficult to find a humanoid robot that is not in the uncanny valley.
- Kokoro, the new Actroid robot from Japan, is probably the best example for robots having reached the other side and now making it out of the valley. This hasn't been lost to the creators, with the word kokoro having the meaning of heart or soul, and probably being a direct allusion to the uncanny valley effect.
- Some of John Nolan's strange animatronics.
- Lo and behold, it's HRP-4C, described as a "Bishoujo android". Say hi to her. Preferably with a rocket launcher.
- This robot that looks like a fleshy armless mermaid.
- While the Big Dog robot doesn't really resemble any living creature, it is the robots leg movements that seem a little unsettling (especially at around 1:12). It looks like two armless humans walking head to head.
- The AFFETTO child robot could really use some work in the design.
- The Geminoid. The most disturbing part is how perfect it is. It looks exactly like a real person right up until you realize it has no limbs and is fused to the desk.
- Three disembodied android faces singing "Freedom" in robotic voices.
- The way this robotic mouth moves its throat is creepy enough, but it's the demonic sounds that make it your nightmare for the next few days...
- Tara the Android. Having made her debut in Fantastic Hey Hey Hey, she has returned to wander the earth spreading even more incomprehensible and terrifying videos. Watch anything on her Youtube channel and you might well die in seven days.
- kaspar the robot: A robot/doll designed to help autistic children.
- How about this robot designed to train dentistry students. Love doll type creepiness plus a stretched-open mouth and robotically-moving tongue...
- From the depth of the Valley, JSC, DARPA, Jacobs Engineering, and General Motors presents Robonaut and his sister, Valkyrie. Tax dollar well spend, indeed.
- Kodomoroid, a gynoid designed to be a newscaster.
- Nadine, the robot receptionist. She looks almost exactly human, exhibits moods and emotions, and apparently even has her own personality. She's a friendly conversationalist and all, but most people still wouldn't want to have a desk next to hers.
- This robot falls into this - between the fact that she has no hair, never blinks, and holds her (often unusual) facial expressions for a lot longer than a real human would... it's hard to see her replacing any humans anytime soon.
- Extra Credits has mentioned the Uncanny Valley several times. First in an episode specifically about it, then revisited in a Halloween episode and again in an episode about Kinect's controls.
- If the Emperor Had a Text-to-Speech Device mentions in episode 20 that the Salamanders invoke this reaction in the common citizens of the Imperium, as they have jet-black, coal-like skin and glowing red eyes.
- A lot of things made with the MikuMikuDance software straddles the line between awesome and awesomely disturbing. What's especially fun is that the software can be used to make a model of just about anything. Case in point: this, a such video featuring Seto Kaiba. And if you're feeling especially brave, here's the same model, dancing to Black Rock Shooter. The creator even apologizes that she couldn't get the model's eyes to stop rolling back into its skull. Besides the eyes, the only creepy thing is that he is singing with a girl's voice.
- Mori no Ando, which doubles up as a Mind Screw.
- For a long time in 3D模拟器Red vs. Blue, the only character whose face we saw was Vic, who was an image capture from the first Halo game. Acceptable enough as he never looked particularly real. Then along comes Reconstruction which gives us the Councilor. A much, much more realistic looking character (same effect, only they used an image from a newer game and used more advanced effects when making his mouth move) but there's still something about the way his face stays alarmingly still while his features are moving... Director Church isn't nearly as bad, but they hardly ever show his entire face, and he does show more movement in his emotions. The Councilor, on the other hand, seems to be this way intentionally, with his deadpan voice and methodical speech pattern.
- The RWBY episode "Alone In The Woods" does this on purpose. A ways in, the eyes of some of the characters get seriously, SERIOUSLY dilated pupils and start talking in a tired monotone. That's not the animation - that's the Apathy Grimm eating away at their will to live.
- Referenced in a Teen Girl Squad cartoon, where Japanese Culture Greg is going to the prom with Chizuko, his robot date.
3D模拟器Science Fiction Greg:3D模拟器 You think I'd be into life-size realistic robots, but that thing makes me want to barf up my earlier energy drink into the one I'm currently drinking.
- Don't watch this at night alone. You were warned. It's called "Going to the Store", and features a computer-animated mannequin in some very weird poses. You might want to procure some Nightmare Retardant.
- This Zelda Fan Film contains the perfect storm of both Uncanny Valley and Off-Model, with Link looking like he had a bad head injury and Ganondorf looking shiny. The animation itself, while decently choreographed, is jerky and unnatural, and the awful lighting makes things even worse. Its sequels show little improvement, and the teaser for the next one features Fi (who already lacked proper eyes) with a misshapen head and her "Hair Hat" looking too realistic, and shots of horseback-riding that resembles someone riding a mechanical bull.
- Squimpus McGrimpus is a Youtuber that specializes in found-footage Fnaf content. His interpretation of Purple Guy- the empty eyesockets, the strangely shaped head, the unhinged jaw- gives a startling similarity to Gaster from Undertale.
- This animator doesn't want her pizza to burn. Of note is at 1:40-1:50, where she does the worst animation of lip-licking you'll ever see.
- The Walten Files: The cartoonish, low-quality art-style the series uses at times can make certain moments much creepier than usual.
- Autism Spectrum Disorders can result in differences in facial expressions and voice tone that often come across as Uncanny Valley to people unfamiliar with ASD.
- This effect sometimes occurs as well with shamans, sages, and other individuals who seem to be tuned into other worlds in addition to this one.
- Western Europeans visiting North America, and vice versa, are known to go through a cultural version of this on occasion. Both cultural areas are very similar in most aspects, but there're just enough minor differences to make everything feel off. Most people don't mind, but to some, it can become so intensely creepy that it ends up ruining their vacation.