Over the course of human evolution, our brains have become highly skilled at recognizing unnatural movement in our fellow creatures. This finely-tuned defense mechanism gives us the ability to quickly identify and avoid diseased or deranged members of the species. It also allows us to easily distinguish between normal people and the walking undead in zombie flicks.

I managed to see The Incredibles and The Polar Express back-to-back this past weekend and this primal ability to identify intrinsically human behavior got quite a workout. But while I was consistently surprised and delighted by The Incredibles, The Polar Express just gave me the creeps.

On the surface, you’d think that The Incredibles would be the film with the problems in the human kinetics department. The characters in The Incredibles are not realistic human beings. They are caricatures whose bodies and facial features are so exaggerated that they bear only a cursory resemblance to real people, and yet everything about them (their body movements, their facial expressions) is quintessentially human.

The Polar Express, on the other hand, is from the Final Fantasy school of computer animation. They’re going for absolute realism; a perfect recreation of the real world and real people. To achieve this, they used sophisticated motion capture technology to record the movements of real actors so they could perfectly recreate those movements using wireframe (and eventually rendered) models. But in the final product, the movement is “off” just enough that it keeps triggering those primal alarms and you find yourself thinking:

“Wow, there is something horribly wrong with her neck.”

…or…

“Ew, his arm should not be doing that.”

But the most cringe-inducing problem is that they obviously didn’t use any motion capture technology to record the actors’ facial movements because the characters’ faces barely move at all. On the whole, their faces are immobile and impassive. Their eyes move, and even glisten realistically, but they never blink. When they talk, their lips only half-move, as if they’ve just come back from the dentist and the Novocain hasn’t yet worn off. It’s disconcerting to say the least, and you have to wonder why they bothered with computer animation at all when they could have achieved the same result with live actors and a couple of crates of Botox.

The movie has other major problems, but even if they hadn’t padded the script with useless crap or shoe-horned lame “roller coaster” scenes into the film for the sole purpose of appeasing the 3D IMAX audiences, the best they could have hoped for was to have people leaving the theater saying, “You know, I think that’s the most heart-warming Christmas movie featuring reanimated corpses ever.”