Octavia
No thoughts, head empty
Could even pick our closest living relatives, chimpanzees and bonobos, as examples.We have dug up a decent number of humans and catalogued cause of death. The archeological review of the past century or so paints some pretty clear pictures that we cannot reject, no matter how much it contradicts the narrative that humans "naturally" behave in any particular way.
Violence and warfare and isolationist survival strategies often arise during high-stress periods. That does not mean that humans are innately violent in all ways, but just that humans can be violent.
Chimpanzees are more commonly known as our closest ancestors, and are particularly well known for being patriarchal and violent towards outsiders. Chimps typically behave like how I was taught humans behave where they live in a larger clan that vigorously guards its territory against any outsiders. They’re also known to engage in genocidal turf wars against other clans just like humans.
Bonobos on the other hand are nearly the same genetic distance from humans, but differ from chimps by being matriarchal and “diplomatic” towards outsiders. Bonobos are sometimes known as “hippie” chimps since they allow outsiders to share resources and bond with their clan, and tend to favour social resolutions to conflict where possible (both bonding and dispute resolution is often handled with sexual or other personal favours).
Most significant difference between the species is that Bonobos typically show more development in areas of the brain associated with empathy and aggression control, but they’re otherwise very similar and can interbreed. Most theories I’ve seen for their very different behaviours suggest that since chimps share a range with gorillas, aggression was selected for. Bonobos on the other hand speciated in an area where the only major competitor was other bonobos, so peaceful conflict resolution was selected for instead.