Uncanny Valley

This is a hypothesis on why sometimes we are scared by human-like robots. It is first devised by Japanese roboticist Masahiro Mori. Essentially he said that we are repulsed by the blurred line between a machine and a human. If the machine is nothing like human, we accept it as a wonderful scientific invention. We also feel positive towards it if it looks and acts extremely like a human. However, if it is resembles a human but have some machine-like actions, it incurs a repulsive feeling in us. Just imagine a human looking robot that has a unnatural smile, it scares people.