When military researchers studied actual combat behavior across multiple wars and armies, they discovered something unexpected: the vast majority of trained soldiers will not kill even when directly ordered to do so, and even when their own safety is threatened.
The figure: 75-80% of trained soldiers in direct combat situations will not shoot to kill, even when the enemy is shooting at them.1
This finding contradicts the common narrative about humans as naturally violent, about soldiers as warriors with killing instinct, about man as a hunting animal designed for predation. If humans had an innate killer instinct, trained soldiers would be eager killers.
Instead, the opposite: humans are reluctant to kill. The reluctance is so strong that it persists even under military training designed specifically to overcome it.
What this reveals: killing is not the human default. Empathy and conscience are the defaults. Killing requires overcoming something fundamental in human nature — not indulging it.
From the perspective of military institutions, the reluctance to kill is a problem that must be solved. A soldier who will not kill is a non-functional soldier. So militaries have developed systematic techniques to overcome this reluctance.
The techniques are well-documented:
Dehumanization: Training soldiers to see the enemy as not-human. Animal, insect, vermin, germ. As the human-ness of the enemy decreases, the reluctance to kill decreases.
Psychological Distance: Creating distance between the soldier and the target. A sniper shooting from 1000 yards experiences less reluctance than a soldier in hand-to-hand combat.
Group Pressure: Training soldiers in units where the group is responsible for the kill, not the individual. The diffusion of responsibility makes the kill possible.
Authority Permission: Establishing clear authority command. When a superior orders the kill, the soldier's resistance to killing is significantly reduced. The soldier can tell themselves "I am following orders; I am not responsible."
Ritualization: Making killing part of ritual and routine. The kill becomes habitual rather than exceptional. Familiar things trigger less resistance.
Trauma and Stress: Putting soldiers into extreme conditions where normal judgment breaks down. Under sufficient stress, the inhibition against killing can be overcome.
None of these techniques create a killer instinct. They overcome the natural reluctance to kill. There is a crucial difference.
The reluctance to kill is evidence of something fundamental about human nature: empathy is baseline. The capacity to experience another being's suffering as meaningful, as mattering, as creating moral constraint — this is the default.
Conscience is not taught; it is uncovered. Remove the institutional machinery that enforces killing, and conscience persists. It is harder to kill a being you see as human than one you see as demonic.
This has profound implications:
Evil Requires Work: Atrocity is not the natural human expression. It requires institutional machinery. It requires systematic dehumanization. It requires authority permission. The machinery is visible, which means it can potentially be disassembled.
Hope Is Grounded in Neurobiology: The reluctance to kill suggests that humans are neurologically organized toward empathy. We are not "naturally" cruel; we are naturally constrained by empathy.
Dehumanization Is Necessary, Not Natural: If killing were natural, dehumanization would be unnecessary. The fact that military institutions must systematically work to overcome reluctance to kill reveals that dehumanization is not a byproduct of some innate hatred. It is an institutional necessity.
The reluctance to kill, while being a problem for military institutions, is the source of one of war's costs: the psychological burden on those forced to kill.
Soldiers who do kill, even when ordered to do so, carry lasting trauma. The guilt, the nightmares, the sense of having violated something fundamental in themselves — these are not rare. They are common.
This suggests: the reluctance to kill is not weakness in soldiers. It is the expression of their humanity. The trauma of killing is the reassertion of that humanity against the institutional machinery that tried to suppress it.
The military has to manage this trauma (through counseling, through reframing the killing as necessary, through group support). But the trauma persists because the reluctance is not gone — it is suppressed but not eliminated.
Psychology describes empathy and conscience as neurological facts — humans have mirror neurons, have capacity for empathic concern, have moral intuitions that constrain harm.
Behavioral-mechanics describes how institutions override these natural constraints through dehumanization, authority, group pressure, and systematic training.
The handshake: understanding human nature (we are empathic) and institutional power (we can override empathy) together reveals why atrocity is possible but not natural, why it requires work, why the machinery is visible.
This enables practical insight: if you want to prevent atrocity, you don't need to change human nature. You need to prevent institutions from assembling the machinery of dehumanization, authority override, and group pressure. You need to protect the innate reluctance to kill.
Ethics has long debated whether humans are naturally good or naturally evil. Keen's finding — that humans are naturally reluctant to kill — grounds a specific kind of hope: we are biologically inclined toward constraint on harm.
The handshake: ethics can stop assuming humans are naturally violent and needing external constraint. Instead, ethics can work with the grain of human nature — recognizing that conscience and empathy are the baseline, and that institutions must work against that baseline to produce violence.
This reframes the ethical task: the goal is not to teach humans to be good (they are naturally inclined that way). The goal is to prevent institutions from systematically overriding that inclination.
Diagnosis: Where do you find yourself reluctant to cause harm, even to those you dislike or disagree with? Where does harming someone feel wrong regardless of whether you have permission to do it?
This reluctance is data. It is evidence of your empathic constraint.
Interrogation: What institutional machinery would be required to make you actually kill (if ordered)? What would need to happen — what dehumanization, what distance, what authority framing — to overcome your reluctance?
Most people cannot imagine overcoming this reluctance, even theoretically. That is the strength of the baseline.
Protection: Where in your community or organization is the machinery of override being assembled? Where is dehumanization happening? Where is authority claiming permission to harm?
Protecting your own reluctance and others' reluctance is how you prevent institutional violence.
You are probably more naturally empathic and morally constrained than you believe. The institutions you live in have told you that humans are naturally violent, that you need control, that conscience is weakness. You have probably internalized this story.
But the evidence suggests otherwise: your reluctance to cause harm is not weakness or pathology. It is the expression of your humanity. Institutional machinery exists specifically to overcome this reluctance because it is strong.
This means: your moral constraints are not imposed from outside; they are you. And the institutions that ask you to harm do so by first convincing you to disown that constraint as weakness.