Why did they only paint animals?

They paint animals, and the lower half of a woman. I think that speaks a lot about their society.

Animals were the ultimate Other and human beings living in nature have always felt profoundly ambivalent towards them. Now they are just pets and curiosities at the zoo, so it's hard for us to imagine the fear and wonder they once evoked. We have "won" - although it may well turn out to be a pyrrhic victory, considering the havoc we have wrought on the environment that sustains us, and of which we are a part.

To hazard an answer to your wonderful question, let's recall that, 30,000 years ago, the ice-free corridor that included the Chauvet region was teeming with large game and predators.

(This period, the Aurignacian, may also mark the beginning of dog domestication, although this is by no means established.
http://anthropology.net/2008/10/18/a-possible-domestication-of-dogs-du ring-the-aurignacian-31700-years-ago/ )

Now even before we became fully human (abstract thinkers - which we already were in the Aurignacian) our survival depended on observing animals very closely.

We were always watching, watching, watching, because animals were the prime source of human survival. We depended upon the fat and calories they provided. As their predators, symbionts and rivals for food, we needed to monitor them and exploit them by any means at our disposal. But if animals provided rich opportunities to thrive, they also presented themselves as the prime agents of our destruction. Far more powerful than humans, capable of annihilating not just individuals but small communities (clans), animal predators had the power of life and death over us, inflicting horrible pain and suffering when they didn't kill humans outright. Animals must have galvanized our emotions long before they affected our more cognitively sophisticated thoughts.

By the time humans became abstract thinkers, whatever ambivalence we already felt towards animals (mammals) became more profound. They seemed beautiful to us. And very much like humans in their needs and cycles of life. The young played, the mothers nursed, males and females copulated, adults gathered food, felt pain, and fought each other. Yet they weren't human and the fact that they could have such power over us while being not wholly like us is what turned them into objects of worship. They seemed to embody a life force, a way of moving and being that was out of our immediate control, yet a force which we deeply envied and sought to appropriate for ourselves.

In short, animals awakened in humans spiritual feelings of awe and wonder, fear and dread, and for all these reasons it was only natural that we worshiped them as soon as our minds became capable of conceiving of animals not simply as beings, but as "forces."



~There is a crack in everything, that's how the light gets in.~

Maybe early man was perceptually like a young child; he saw what was out there before he developed a concept of himself apart.

One possible explanation is in the film. When light is behind the people, whether camera lights or a long ago fire, human shadows project onto the cave wall. Perhaps the paleo people enacted past or future hunts or interacted with the drawn creatures somehow.

One thing I find interesting is not only that there were barely any human figures, but that since the paintings spanned thousands of years, the trend apparently continued for thousands of years. So it's not like the reason is just that those were the norms of one tribe/culture.

They were tribal hunter-gatherers. Their religion is always Animism:

Animism is the belief that objects, places, and creatures all possess a distinct spiritual essence. Potentially, animism perceives all things—animals, plants, rocks, rivers, weather systems, human handiwork, and perhaps even words—as animated and alive. Wikipedia