The "Phenomenon of the Disturbing Valley", translated from Japanese 19981; 27671; 21619; 12398; 35895; 29694; 35937; (bukimi no tani guenzoo) is the name used by robotics professor Masahiro Mori in 1970 to describe human behavior in the face of a machine that no longer looks like an anthropomorphic robot but has the traits and gestures of a real person. He created a graph to show the reaction to different machines starting with an industrial mechanical arm and the acceptance was increasing as the robot seemed more human; but when the differences were minimal (empty look, unnatural speed of the lips when simulating speech, . . . ) there was an immediate rejection, which disappeared when the android was practically indistinguishable from a person. This "valley" in the graph and its measurement are not properly proven, although as technology allowed to create more sophisticated 3D animations and androids the phenomenon began to be verified, but there is no agreement on its causes and its interpretation is still discussed. The "disturbing" added to the word "valley" is a reference to previous literature on psychology and sociology, which according to the translation one chooses is also found as "strange", "sinister" or "mysterious".
