An idea that I got after reading Guns, Germs, and Steel was that at a basic level, killing other humans is the correct response to most threats, annoyances, or disagreements. Manager wants to micromanage with story points? Kill him. Problem solved.
Now, clearly, if everybody is killing everyone beyond their immediate family, it is hard to have any sort of larger society. Living and collaborating under constant threat of immediate death wouldn't work. So we have a large set of social adaptations to limit the killing and restrain ourselves.
My point here, is that 'why do human kill other humans' is a less interesting question than 'why are the social adaptations that prevent killing not taking affect?' The problem of fighting isn't a moral failing, or some flaw in the human soul. Killing makes sense within the decision making scope of our conscious brains, and is the result of inadequate build up of collective structures of inhibition that are required to have larger groups of people in closer contact with each other, and as the groups get bigger and the contact becomes closer, we need to engineer new schemes for inhibiting the 'lets just kill them off and solve this once and for all' urge.
Now, clearly, if everybody is killing everyone beyond their immediate family, it is hard to have any sort of larger society. Living and collaborating under constant threat of immediate death wouldn't work. So we have a large set of social adaptations to limit the killing and restrain ourselves.
My point here, is that 'why do human kill other humans' is a less interesting question than 'why are the social adaptations that prevent killing not taking affect?' The problem of fighting isn't a moral failing, or some flaw in the human soul. Killing makes sense within the decision making scope of our conscious brains, and is the result of inadequate build up of collective structures of inhibition that are required to have larger groups of people in closer contact with each other, and as the groups get bigger and the contact becomes closer, we need to engineer new schemes for inhibiting the 'lets just kill them off and solve this once and for all' urge.