The concept of the Uncanny Valley was introduced in the 1970s by a Japanese roboticist called Masahiro Mori. Mori also happens to be the founder of Robocon (the first Japanese robot-building competition) and is the President of the Mukta Research Institute, which studies the metaphysical implications of robotics.
Mori loved designing robots, and as he was good at it. The more he learned, the more realistic his creations looked — with synthetic skin, moving eyes and other fantastic feats. But Mori noticed something interesting: While the simpler robots created a positive reaction from humans around, the more realistic or human-like they became, the more people became scared of them — even though they were excellent examples of robotics.