The Uncanny Valley

In 1970, Japanese roboticist Masahiro Mori published 'Bukimi no tani' (The Uncanny Valley), a brief but influential essay proposing a hypothesis about human emotional response to robots and androids. Mori observed that as robots become more human-like in appearance and movement, people's emotional response becomes increasingly positive—until the robot reaches a point of near-human similarity without achieving perfect human likeness, at which point the response becomes sharply negative, evoking discomfort or revulsion. This dip in emotional response before climbing again toward acceptance at full human similarity forms a 'valley' in the graph of emotional response versus human likeness.

The essay has become foundational to robotics, animation, and AI design, influencing how creators approach the design of humanoid robots, CGI characters, and virtual avatars. The concept explains why some near-human but imperfect representations (uncanny dolls, early motion-capture films, certain robots) provoke unease, while either clearly non-human designs or perfectly human ones do not. Mori's work remains central to discussions of human-robot interaction, artificial intelligence ethics, and the psychology of artificial entities.