I would say language sets us apart from the animals.  Animals have no ability to communicate with each other in any meaningful way and so must act mostly on instinct to survive.

This is completely untrue with humans, where we discuss things, we arbitrate between people with disagreements, we make rules, etc.  We are not in the same state of nature that other animals are in and it is incorrect for people to say, "oh, this is human nature".  It's not.  Most people have no interest in dominating others so how can it be human nature?  It's like saying killing is human nature because some humans like to kill others.  Or raping is human nature because some people like to rape.  etc