A closer look
Humans are perfectly fine with cartoonish robots and totally fine with actual humans, but anything stuck in the middle triggers a profound, ancient terror. Roboticist Masahiro Mori termed this the "uncanny valley." When artificial faces, like the eerily smooth CGI characters in The Polar Express, look about 90% human, they suddenly stop registering as "cute machines" and start registering as "diseased humans." Our evolutionary pathogen-avoidance system violently kicks in, analyzing the dead eyes and slightly unnatural movements as a corpse reanimating or a person carrying a deadly neurological plague. The revulsion is not a critique of the technology; it is a primal survival instinct screaming at you to run away.
