What Is the Uncanny Valley and Why Is It So Weird?

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The unsettling truth behind things that are almost (but not quite) human

Co-authored by Brittney Crabb and Amy Bobinger, BA

Last Updated: September 26, 2025 Fact Checked

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• What is the Uncanny Valley?
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• Examples
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• Origin
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• Theories
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• Is it real?
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• How to Avoid It
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• Video

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Have you ever seen a face that was life-like at first glance, but when you looked closer, it turned out to be a robot or CGI character? If it gave you an uneasy feeling, you experienced the Uncanny Valley effect. We’re diving deep into the Uncanny Valley phenomenon, including what it is, where you might have seen it, where the term came from, and why it happens, all with the help of clinical therapist and adjunct professor Rebecca Tenzer, MAT, MA, LCSW, CCTP, CGCS, CCATP, CCFP.

What are Uncanny Valley faces?

Clinical therapist and adjunct professor Rebecca Tenzer, MAT, MA, LCSW, CCTP, CGCS, CCATP, CCFP says the Uncanny Valley is “that uneasy feeling you get when something feels off because it looks human, but not quite.” Some common examples of Uncanny Valley faces include:

• Humanoid robots
• Realistic CGI characters with subtle imperfections
• AI avatars
• Lifelike dolls
• Wax figures

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Section 1 of 6:

What is the Uncanny Valley?

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1. 
   Uncanny Valley explains the uneasy feeling we get around realistic human-like figures. When something looks almost (but not quite) exactly like a human, it can create a psychological response in people that causes them to feel disgust, unease, or a creepy feeling, says Tenzer. If you graph the Uncanny Valley effect, it shows that people increasingly like things that have human-like features—but only up to a certain point. Once something looks too similar to a person, people’s reactions drop steeply (hence the term “Uncanny Valley.”).

   • Theoretically, if something looks passably enough like a human, people’s reactions to it will warm again.
   • Tenzer asserts that, “With all of the technology we have nowadays, [the Uncanny Valley is] not an uncommon occurrence.” She says VR/CGI characters, cartoons, wax figures, AI avatars, lifelike dolls, and animatronics can all potentially trigger the effect.
   • Tenzer says something typically triggers the Uncanny Valley effect because it looks human but doesn’t display human characteristics. For instance, a CGI character might blink less often, exhibit unusual behaviors, or speak with a robotic-sounding voice.
   • There is some debate in the scientific community about the validity of the Uncanny Valley (see the section ”Does the Uncanny Valley Exist?”, below).

   Meet the wikiHow Expert

   Rebecca Tenzer, MAT, MA, LCSW, CCTP, CGCS, CCATP, CCFP is a clinical therapist and adjunct professor with over 18 years of clinical and educational experience in the mental health field.
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Section 2 of 6:

Examples of Uncanny Valley Faces

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1. 
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   Uncanny Valley faces are common in CGI cartoons and movies. If characters look too much like humans but don’t quite match up in terms of movement, expression, or even the texture of their skin, it can create an unsettling Uncanny Valley effect that distracts viewers. Video game characters and AI-generated avatars also frequently trigger Uncanny Valley. Popular examples include:

   • Baby Billy in Pixar’s Tin Toy (1988)
   • The Polar Express (2004)
   • Final Fantasy: The Spirits Within (2001)
   • Beowulf (2007)
   • The Lion King (2019)
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   Famous robots and AIs often trigger Uncanny Valley. As the field of robotics continues to advance, scientists are capable of creating robots that appear more and more lifelike. However, there’s still usually some disconnect between a real human’s appearance and that of a robot, which can lead to an Uncanny Valley effect. Examples of this include:

   • AVA, the AI avatar for the software HelpDesk
   • Sophia from Hanson Robotics
   • Ameca from Engineered Arts
   • Geminoid HI-1 by Hiroshi Ishiguro
   • AI-Da the painting robot
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   Prosthetics may also trigger the Uncanny Valley effect. Prosthetic limbs and fake teeth often create a slightly unsettling feeling—they look realistic but not quite real. Or, they may look realistic but feel cold or rubbery. The difference between what we expect and what we experience may be the reason we feel uneasy.

   • Some people may even experience the Uncanny Valley effect when they see people who’ve had obvious cosmetic surgery.
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Section 3 of 6:

Origin of the Uncanny Valley Concept

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1. 
   The term Uncanny Valley comes from an essay by Masahiro Mori in 1970. In the essay, Mori—a robotics professor—wrote about his observations regarding people’s reactions to humanoid robots. He called the concept “bukimi no tani genshō,” which was translated into “Uncanny Valley” by Jasia Reichardt in 1978.

   • In addition to robots, Mori applied the concept to prosthetic limbs and even zombies.
   • Mori wasn’t the first to contemplate this psychological theory. Freud wrote about the “uncanny” in 1919—a fear of something familiar yet unsettling.
   • Charles Darwin wrote about a similar concept in The Voyage of the Beagle, attributing his revulsion to a certain snake to the fact that its features were similarly proportioned to a human’s.

Section 4 of 6:

Theories About Why We Experience Uncanny Valley

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   Uncanny Valley may be based on an evolutionary instinct to avoid diseases. Uncanny Valley may be triggered because something reminds us of a corpse—human in appearance, but lacking movement and emotion. The instinct to avoid dead bodies likely helped protect humans from disease (and possibly predators). Similarly, it may be based on an instinct we evolved to avoid people who are visibly ill or disfigured by an ailment.

   • Uncanny Valley may arise from mating instincts. We’re wired to be attracted to the healthiest-looking partners to ensure our offspring are healthy. Feeling repulsed when something seems “off” may be a product of that impulse.
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   The Uncanny Valley response may be psychological. Things that are somehow familiar yet not can trigger a feeling of discomfort, which Freud writes about in his essay on “The Uncanny.” This may be due to the fact that it challenges our beliefs about what is a human and what is a robot.

   • Tenzer explains that, “Our minds pick up on little inconsistencies that don’t match what we are used to, and [that] creates discomfort.” She says, “Normalcy creates consistency and comfort, and when things are out of the ordinary, it throws us off.”
   • Robots’ stiff, mechanical movements may also trigger an unconscious fear of losing control over our own bodies.
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   It may trigger a fear of being replaced or eliminated by technology. Uncanny Valley may be rooted in a subconscious fear that realistic AI or robots could take our place without anyone else knowing. It may also be based on the fear that one day, they’ll entirely replace humanity.

   • For some people, Uncanny Valley may be rooted in spiritual or moral beliefs—that there’s something inherently “wrong” with a soulless machine that looks and behaves like a person.
   • Some people theorize that this instinctive fear developed because early humans faced a predator or enemy that looked almost (but not quite) identical to humans. This may have been a relative of humans, like Neanderthals or Denisovans. Some theories attribute it to mythological creatures, like shapeshifters or fae.
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   We might have a neurological reaction that triggers unease. If you look at something that’s clearly non-human, you may find it more relatable if it has some human-like characteristics. But if you look at something non-human that seems to be human at first glance, your brain might start focusing on all the ways it’s different. This cognitive dissonance may trigger an uncomfortable feeling.

   • For instance, R2D2 and Wall-E are beloved robotic characters. They don’t look anything like humans, but as the characters develop, we start noticing details that make them more human-like. On the other hand, if you focus on an overly-realistic AI avatar like AVA, you may start noticing all the ways it’s different from people.
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Section 5 of 6:

Does the Uncanny Valley Exist?

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1. 
   Some people disagree that Uncanny Valley exists. Mori didn’t publish a scientific study proving Uncanny Valley—he published an article describing a phenomenon he’d observed. A lack of scientific evidence has led some to dispute the concept entirely. Criticisms include:

   • Uncanny Valley may be the result of several phenomena rather than one single event.
   • People’s cultural backgrounds may make them more or less likely to experience the effect.
   • Younger generations who have had more exposure to life-like androids may not experience Uncanny Valley.
   • Uncanny Valley may be triggered even when the subject is more abstract and has less resemblance to humans.

Section 6 of 6:

How to Avoid Uncanny Valley

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1. 
   The easiest way to avoid Uncanny Valley is to make characters less life-like. If you’re a designer, people may reject your work if it triggers the Uncanny Valley effect. The best way to avoid this is to create characters that are obviously artificial—perhaps by keeping them a little more cartoon-like. You can also attempt to make the characters so realistic that they can’t be distinguished from humans, although this has so far proven difficult to execute.

   • Avoid mixing life-like and obviously artificial features. For instance, if your character looks like a robot but speaks with a near-perfect human voice, people may find it unsettling. Uncanny Valley can also happen if a character looks human but has the wrong skin texture.
   • Pay attention to movement and expression. If your character looks like a human but moves in a mechanical way, it can create an Uncanny Valley effect. Similarly, if your character doesn’t emote appropriately, it can seem dead or robotic.
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