Animal Instinct.

I have witnessed many animals exhibit human traits, and I've seen many humans behave like animals. Darwin's evolution has taught us that we're all related. The differences between us and the animal kingdom are FAR less that we arrogantly would like to believe (we are just another species of ape). I would say: 'There are no differences worth mentioning'.

Animal Instinct. Created using Bryce and Poser.

If I were pushed to say what our main difference was, I would say humans are the most aggressive of the animal kingdom. To get what we want we will destroy anything that gets in our way, even if that means destroying members of our own species. How else could we have attained our dominant position on the planet?