Human-Robot Interface: The Theory of the "Uncanny Valley"

If you are interested in robotics, you have probably already heard of the "uncanny valley" curve. This term is a translation of the expression "uncanny valley," "uncanny" being the English translation of the Freudian term "unheimlich."

The ‘Uncanny Valley’ theory was proposed in the 1970s by robotics engineer Masahiro Mori. This concept corresponds to the base part of a curve analysing emotional responses to the anthropomorphism of robots. In other words, the emotional response depending on the degree of resemblance between the robot and a human being.

This ‘Valley of the Uncanny’ is the zone of negative perception felt by a human observer when faced with a humanoid robot. This curve shows that there is no middle ground: either the robot looks perfectly human, or it looks like a robot. However, negative feelings arise when the robot looks ‘badly’ like a human being; it becomes frightening, classified in the category of corpses or zombies, triggering reflexes of mistrust or even discomfort. As this curve shows, once this ‘uncanny valley’ has been crossed, the acceptance rate increases again. This is a zone that must be crossed for a humanoid robot with a human appearance to be accepted.

David Hanson, criticises this theory by demonstrating that the context of the person judging the robot must also be taken into account.

Empathy through physical resemblance, but not only that...

Psychologist Gunnar Johansson demonstrates that it is not only appearance that elicits empathy, but that there is also empathy for movement. He has shown that the brain is able to recognise whether a movement is biological or not based on a few dynamic visual cues. This ability is linked to the activity of a specific area of the temporal cortex. In other words, even if a robot does not look like a human but behaves like one, it triggers empathy.

A perfect example of this is the outrage some people felt when watching the video of Atlas, the Boston Dynamics robot, getting ‘kicked in the butt’ during a test. Yet these same people feel no empathy when they hit their computer or coffee maker when it malfunctions.

Human beings therefore have this deeply ingrained ability to feel empathy towards anything that resembles or behaves in a manner similar to humans, whether through appearance and/or movement. But beware, if we venture into the ‘uncanny valley’, empathy gives way to fear and even discomfort.

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Ressources : Le journal du CNRS : Petit détour par la vallée de l’étrange