I used to think that animals deserved more respect than humans because they did everything to survive. It was all a process of evolution - survival of the fittest. They weren't capable of being mean or evil. (However, my experience with pets has taught me animals can premeditate, have a sense of humor, steal, envy, trick, and want.)
The more I think about it, humans also just do what they do to survive. In fact, I believe a lot of how we behave is sub-conscious - tactics that help us to survive. Whether a predator or victim, abuser or abused, we have learned behaviors to survive this world. No one is really bad or good.
What do you think?
As an example, here is an article on depression as an evolutionary survival mechanism: http://www.suite101.com/content/evolutionary-psychology-depression-a298146