Uncanny Valley
The increasing unease one experience as an entity approaches realistic humanoid characteristics or appearance, where the more realist (but still subtly not human) the entity appears, the greater unease or cold feelings are felt, where if the entity is decidedly not humanoid then we experience little unease.
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Origin
First proposed by Japanese robotics professor Masahiro Mori in a 1970 essay for the journal Energy, based on his observations of people's reactions to increasingly lifelike prosthetic hands and humanoid robots. The original Japanese term bukimi no tani was translated as 'uncanny valley' by Jasia Reichardt in 1978. The concept gained widespread attention decades later with advances in CGI and robotics.
Updated February 22, 2026