Androids, avatars, and animations aim for extreme realism but get caught in a disturbing chasm that has been dubbed the uncanny valley. They are extremely realistic and lifelike — but when we examine them, we see they are not quite human. When a robotic or animated depiction lies in this “valley,” people tend to feel a sense of unease, strangeness, disgust, or creepiness.
The uncanny valley is a term used to describe the relationship between the human-like appearance of a robotic object and the emotional response it evokes. In this phenomenon, people feel a sense of unease or even revulsion in response to humanoid robots that are highly realistic.
Origins of the Uncanny Valley
The term was first coined and described by the Japanese roboticist Masahiro Mori in an article published in 1970. In his work, Mori noted that people found his robots more appealing if they look more human. While people found his robots more appealing the more human they appeared, this only worked up to a certain point.
When robots appear close but not quite human, people tend to feel uncomfortable or even disgusted. Once the uncanny valley has been reached, people start to feel uneasy, disturbed, and sometimes afraid.
“I have noticed that, in climbing toward the goal of making robots appear human, our affinity for them increases until we come to a valley, which I call the uncanny valley,” Mori explained in his seminal paper on the topic.1
Mori used a number of examples to clarify this idea. An industrial robot has little human likeness and therefore generates little affinity in observers. A toy robot, on the other hand, has a more human likeness and tends to be more appealing. A prosthetic hand, he noted, tends to lie in this uncanny valley — it can be highly lifelike yet generates feelings of unease.
Mori and others have suggested that the uncanny valley is an aversive, evolved response to the potential threats of death and disease. Because something is human-like but not quite lifelike, it may evoke the same response that people feel when they encounter something that is dead or dying.
Theories also suggest that the uncanny valley may exist due to the difficulty in determining what category an entity belongs to.
When something approaches a point where it seems to transition from one to the other, it can trigger feelings of cognitive dissonance. When people hold conflicting beliefs, they tend to experience feelings of psychological discomfort.
In this case, there is a conflict between the belief that an entity is human and the belief that it is not human. Something that looked human might abruptly appear nonhuman, or it may even shift back and forth as the viewer observes it.