Human Beings are inherently NON-violent towards other Human Beings.
IMHO, there are always more sheep than wolves. And fewer yet sheep dogs.
I have no statistics, but if I look at the number of people who actually commit violent acts (the number who kill would appear to be exceptionally smaller even among the military) compared to the over all population, I could and would conclude (inherent or not) that human beings are decidedly more non-violent.
IMHO, violence and killing is not genetic, biological, or hormonal. I have seen no research that states if these genetic markers or these biological conditions exits, the person is inevitably going to commit acts of violence and kill. There is a lot of research that suggest its a psychological frame of reference or choice that is learned.
But, I could be wrong. I often am.