Uncanny Valleys of Human Interaction

The 'uncanny valley' describes the uneasy reaction people have to robotics that look very similar to human beings, but they know are artificial.  A lengthy piece on the topic.  Of course a valley has a rise on the other side, and if we ultimately don't know its artificial?  Sounds arcane, but a very interesting view of our own built in emotions.  Also, in the WP, from which the example image on the right comes.