i think he means killing for other's property, as in e.g. the army, to fight in wars. that's not a natural instinct at all, people need to be brainwashed into it, with a narrative. it actually starts pretty soon, at tender age, where tales and movies show examples of 'good' reasons to kill the 'bad' guys. when it matters, media and propaganda make sure to clearly show who the 'bad guys' are, and reduce them to non-human form, not only for the actual killers to do so without remorse, but for the rest of the group to sanction and support it: mothers send their kids to the cause, and all pay taxes to fund the whole thing.
this of course exploits our lizard brain and our violent instincts, which are there but are not the whole story. but no, being killers is not our natural state at all.