Robots and artificial intelligence (AI) are already part of our lives, but there are things about them that continue to cause rejection. Specifically, it has been found that many people have a particular aversion to robots that look too human and that try to imitate real people's behavior.

The name uncanny valley comes from a graph that shows people's emotional response to an animate or inanimate object that mimics people's traits and behavior. At first the response is more positive the more similar it is to reality, but from a moment in which it is too similar to a real person, this response becomes a strong rejection.

This phenomenon is not exclusive to robotics, but also occurs with other replicas such as dolls or wax statues. However, robots, by being able to imitate people's movements and voices, produce an especially strong rejection that can even amount to fear. It has recently been proven that this also happens, although to a lesser extent, with hyperrealistic CGI (computer generated image) images, especially if they are of deceased people.

The rejection is more intense the more sensory-realistic the robot is, that is, if in addition to having very human features it also has a voice and even synthetic skin.

On the other hand, the aversion seems to be less in people who have daily contact with this type of robots, mainly their creators. It has also been observed that rejection can lessen over time and that some people, although not all, can get used to and tolerate these humanoid robots.

Why are we concerned by too realistic robots?

Since the appearance of the first robots, attempts have been made to explain this emotional response of people towards them, dividing them into three categories according to their appearance: those that are machine-shaped generate a feeling of indifference, those that have a defined appearance evoke various emotions, but those that are too similar to reality provoke a feeling of rejection.

Various hypotheses have been proposed for the uncanny valley phenomenon. Most take as their starting point the contradiction produced by seeing something that we know is not alive but that behaves as if it were: it feels strange to treat it like a machine because it looks too much like a person, but it feels even stranger to treat it like a machine. treating him like a person when we know he is not. This may explain why their developers do not feel the same aversion, since having created them they are more directly aware of the fact that they are machines.

Over time, other alternative or complementary hypotheses have emerged. In recent years, one that attempts to explain the uncanny valley from an evolutionary point of view has gained support: according to some scientists, it is a psychological barrier that we as Homo sapiens have towards other human species with which we had competed for resources in the past. resources, so we perceive all-too-human robots as potential rivals.

Finally, other theories point to their resemblance to an animated corpse as the reason for this rejection of humanoid robots, which evokes ancestral fears of “undead” creatures such as vampires, ghosts and zombies; and makes us perceive them as a threat.