The uncanny valley
The robotics field undoubtedly has some major challenges to face before any Ray Bradbury visions of our android-filled future are to be realized. One of the biggest may be a problem not of mechanics but of human psychology: the fact that most people find things that look almost but not quite human to be incredibly creepy. Take, for instance, the weird-looking animated "people" in the movies Polar Express and Final Fantasy; they looked uncannily like people -- but not just like people -- and the movies bombed. In 1970, Japanese roboticist Masahiro Mori tried to figure out why people are repulsed by the uncannily human, and he came up with this fascinating graph:
Note that "familiarity" here means emotional response. What's interesting is that the more human something looks -- up to a certain point -- the more we respond favorably to it. (That's why we like Alf and Shrek and Little Nemo; they're anthropomorphized to seem more human.) But get too close to looking human, and our affection turns to revulsion, and quick. That's what mori calls the "uncanny valley," which in the case of non-moving objects includes not-quite-human things like corpses, and in the moving (and thus more repulsive) category includes zombies. If Mori were making this graph now and not 37 years ago, we're pretty sure he would've placed some of the latest triumphs of robotics near the nadir of that valley.
Take the work of Dr. Hiroshi Ishiguro, one of Japan's leading roboticists. He's made several robots in the last few years that are likenesses of real people, including himself, a prominent Japanese newscaster and even his four-year-old daughter. They're all downright creepy, and the more advanced and realistic they get, the creepier they get. (When his daughter saw her robot double, she freaked out, and thereafter wouldn't go anywhere near the thing.) But don't take our word for it: we found some video of Dr. Ishiguro's robots, and some videos of zombies. Which are creepier?
Thanks to Damn Interesting for the info.