A couple of days ago I wrote about the FurReal cat, and how much it creeps me out. Essentially, I argued that robot-looking robots are cool — like R2D2 — but ones that attempt to genuinely mimic life-forms (like that fur-covered, purring animatronic cat) just give me the heebie-jeebies.

As it turns out, I’m not alone. In the Collision Detection message boards, Alan Daniels posted a link to a superb essay that analyzes my creeped-out reaction. The essay,“The Uncanny Valley”, is by Dave Bryant and discusses the theories of Japanese robotocist Masahiro Mori. Mori analyzed human reactions to robots and monsters in sci-fi flicks, and developed a theory:

Stated simply, the idea is that if one were to plot emotional response against similarity to human appearance and movement, the curve is not a sure, steady upward trend. Instead, there is a peak shortly before one reaches a completely human “look” … but then a deep chasm plunges below neutrality into a strongly negative response before rebounding to a second peak where resemblance to humanity is complete.

This chasm — the uncanny valley of Doctor Mori’s thesis — represents the point at which a person observing the creature or object in question sees something that is nearly human, but just enough off-kilter to seem eerie or disquieting. The first peak, moreover, is where that same individual would see something that is human enough to arouse some empathy, yet at the same time is clearly enough not human to avoid the sense of wrongness. The slope leading up to this first peak is a province of relative emotional detachment — affection, perhaps, but rarely more than that.

Go check out the paper and dig the graphs Mori charted — our affection for robots rising as they become slightly more lifelike, but then plunging when they look almost, but not quite, human. The “uncanny valley” is that steep, sudden plunge on the chart: The place where robots suddenly seem not charming and kooky, but eerie.

And as Alan noted on his own posting:

I think I understand why the robotic cat creeps you out. Frankly, it creeps me out too. But, if the robotic cat looked absolutely 100 percent like a real cat, down to the the last purr and flick of the tail, I wouldn’t give a second thought to the fact that it’s a robot. Being a robot is fine, being a cat is fine, but when it tries to be something in the middle, it fails at both, and the overall effect is creepy and alien.