The Uncanny Valley

There are generally two methodologies to robot technology: humanoid robots designed to simulate the human form and function as closely as possible and the utilitarian robots designed to perform dirty and dangerous tasks quickly and efficiently. With a few exceptions the Japanese are the leading creators of humanoid robots.

These robots can look and move surprisingly human and when they become too human researches have noticed a reaction of revulsion from viewers. This increased level of discomfort with these machines is known as the uncanny valley.

The concept of "the uncanny" was developed in the early 1900's by psychologists is an object that is very familiar but at the same time unfamiliar. This contradiction creates an feeling of anxiety in the people viewing the uncanny object. In reference to robotics, the term "uncanny valley" was created by roboticist Mashario Mori. It specifically refers to the dip noticed when the emotional response of human subjects are plotted against how "human" a robot appears.

Something like an industrial robot is very inhuman and therefore there is little emotional reaction from observing humans. Toys and stuffed animals are slightly more human but cute and generally elicit positive emotional reactions. The drop into the uncanny valley begins with a dead human body. It is very human like in form but unfamiliar in a negative way. Therefore the emotional reaction is generally negative. A humanoid robot is much like a zombie in that it looks like a human and moves like one. All the signs of human life are there but something is missing.

The concept of the uncanny is generally important only in the design of human robot and robotic interface systems. The problem has caught the attention of digital movie makers which have noticed strong negative reactions to very human looking characters in animated movies. A good example of this is in the 2004 movie The Polar Express. In this film Tom Hanks character looks and behaves extremely life like, but it is still a digital representation and lacks the true human character. As a result viewers feel uncomfortable and disturbed by the portrayal and describe the movie as "creepy" or otherwise unsettling. This effect has also been noted in Final Fantasy: The Sprits Within and Beowulf which, all where not highly successful movies.

Obviously the problem is not with digital movies in general: Shrek, Finding Nemo, and Toy Story all feature digital creatures that where tremendously popular with both adults and children. Pixar has built an empire on these movies which are cheap and easy to produce. The difference is these characters where not designed like humans. Like stuffed animals they are, while still human-like, ultimately cute or cartoonish representations of the human form. This design avoids the pitfall of the uncanny valley.

The human face alone has dozens of degrees of freedom. To fully and faithful represent this level of complexity requires mechanical systems and software that simply does not exist today. In order to create a humanoid robot that does not make the user uncomfortable much more work needs to be done. Perhaps the best choice for today's robots are machine-like- think Roomba.