Uncanny valley

Some robots look like people.

They can look very real. But sometimes they look strange. This can make us feel odd.

As a robot looks more like a human, we like it more. But then, something changes. If it looks almost human, we may feel a bit scared. This is called the uncanny valley.

It is like a dip in a line on a graph. The feeling goes down and then back up. This happens when things look a little bit strange.

Moving robots can make this feeling even stronger. Even computer pictures can cause this. It can happen with dolls too.

We may feel this way because the robot looks odd. It can feel like it is not quite right. This is a very interesting way we react to things.

Some robots look a lot like people.

At first, we like them more as they look more human. But then, something strange happens. If a robot looks almost human, we may feel a sense of fear or disgust. This is called the uncanny valley.

Think of a line on a graph. The line goes up as robots look more human. Then, the line drops into a deep dip. This dip is the valley. After the dip, the line goes back up. This happens when the robot looks exactly like a real person.

Why do we feel this way? Scientists have many ideas. Some think it is about health. We might feel disgust if a robot looks like it has a disease. Others think it is about fear. A robot that looks almost real might remind us of death. It might even make us feel that humans are not special. Some people feel uneasy because the robot's movements are jerky. This can make us feel like we are losing control. These feelings can happen with robots, dolls, or even computer pictures.

Have you ever seen a robot that looked almost exactly like a person?

You might have felt a sudden sense of eeriness or even disgust. This strange feeling is known as the uncanny valley. It is a special idea in psychology and art. It describes how our emotions change as things look more human. We usually like things more when they look friendly and lifelike. However, when something looks nearly perfect but is slightly off, it can feel very wrong.

This feeling works like a dip on a graph. Imagine a line that climbs steadily upward as a robot gains human features. This happens because we feel more empathy for things that look like us. But suddenly, the line drops into a deep, steep hole. This hole is the valley where the robot looks "almost" human. In this zone, the robot causes feelings of revulsion instead of liking. Once the robot looks exactly like a real person, the line climbs back up again.

A professor named Masahiro Mori first shared this idea in 1970. He wrote about it in his book on robotics. Later, in 1978, a writer named Jasia Reichardt translated his work into English. She used the term "uncanny valley" for his concept. This name connects to older ideas about the "uncanny" from thinkers like Ernst Jentsch and Sigmund Freud. These men studied why certain things feel strange or spooky. Today, we see this effect in many digital places. It shows up in 3D computer movies and even in virtual reality.

Scientists have many theories about why this valley exists. One idea is called pathogen avoidance. This theory suggests we feel disgust to stay away from germs or sickness. Another idea involves our fear of death or losing control. A robot with jerky movements might make us feel uneasy. Some people also worry that very human robots might make humans feel less special. This is a challenge to our own identity as living beings. Even monkeys have shown similar reactions in studies with 3D faces.

You can find the uncanny valley in your favorite movies or video games. It happens when a digital character looks very real but moves in a strange way. It can also happen with lifelike dolls or animatronics at theme parks. Even artificial intelligence can create this feeling in our minds. As technology gets better, these machines look more and more like us. We are still learning how to build robots that feel friendly. Understanding this valley helps engineers make better tools for humans to use.

The uncanny valley is a hypothesized psychological and aesthetic relationship. It describes how our emotional response changes based on how much an object resembles a human.

This concept is vital for robotics engineering and digital animation. It explains why some lifelike characters feel friendly while others feel deeply unsettling. As technology advances, understanding this phenomenon becomes more important for human-robot interaction.

The mechanism follows a specific pattern of emotional shifts. As a robot's appearance becomes more human, our empathy and positive feelings usually increase. However, when the robot reaches a point of being "almost" human, the response drops sharply. This creates a steep decrease in our emotional connection, leading to feelings of revulsion or eeriness.

This sudden dip is the "valley" in the term. If the robot eventually becomes indistinguishable from a real human, the emotional response climbs back up toward human-to-human empathy levels.

Researchers have proposed several distinct theories to explain why this happens. One theory is pathogen avoidance. This suggests that visual anomalies in a near-human entity trigger a disgust response. This response may have evolved to help us avoid diseases or parasites. Another theory is mate selection. This idea posits that we instinctively avoid features that might indicate low fertility or poor health.

Other theories focus on mortality salience, where near-human robots remind us of death. This can happen through seeing disassembled androids or witnessing jerky, unnatural movements.

There are also cognitive theories regarding how our brains process these images. The theory of conflicting perceptual cues suggests that we experience psychological discomfort when we see mismatched information. For example, a figure might look like a human but move like a machine. This creates perceptual tension. Some studies show that people take more time to classify these faces. This suggests that the brain struggles to decide if the object is a human or a robot.

History shows that this concept has deep roots. Robotics professor Masahiro Mori first introduced the idea in 1970. He presented it in his book regarding robotics. In 1978, Jasia Reichardt translated his work into English. She used the phrase "uncanny valley," which linked the idea to earlier psychoanalytic concepts. These included Ernst Jentsch’s 1906 essay and Sigmund Freud’s 1919 essay on the uncanny. These thinkers explored why certain things feel strangely familiar yet unsettling.

The significance of the uncanny valley is seen in modern digital technology. We see it in 3D computer animation and virtual reality. It also appears in lifelike dolls and animatronics. As verisimilitude, or the appearance of being true, increases in digital tools, the debate grows. Even animals show signs of this effect. In a 2009 study, monkeys showed less interest in realistic 3D monkey faces than in real photos or unrealistic faces. This suggests the reaction might be deeply rooted in biology.

Finally, the uncanny valley connects to broader questions about human identity. Some argue that highly humanlike robots pose a threat to our distinctiveness. They may challenge the idea that humans are unique or "special." This can cause existential anxiety. Some researchers even suggest an "uncanny valley of the mind." This refers to the potential aversion people might feel toward highly advanced artificial intelligence. As machines become more emotion-sensitive, they may challenge our very definition of being human.