Psychology of Killing

Hollywood is great at making war seem so simple and strait forward. It makes the watcher believe that people kill each other because they are told, because it is kill or be killed, the enemy is hated or whatever. Hollywood tries to make us believe that all soldiers fire at each other, desperately attempting to hit and kill each other. While there is some truth in the matter, it is mostly wrong.

An excellent book to read on this subject is “On Killing : The Psychological Cost of Learning to Kill in War and Society” by Dave Grossman. I highly recommend you read this book as it goes into great detail on the subject, much more than can be covered here.

When most people talk about killing, they are like virgins talking about sex. You can talk about it all day, you can fully understand the mechanics involved but when the time comes there is so much more involved than the person thought.

When bullets start flying emotions start running high and that can have a powerful effect on how a person sees things. Five hundred combatants can see five hundred different things. In war every fighter will likely see things differently. The movies like to make people think that the world is black and white, not different shades of gray.

A look at history might help illustrate what I am talking about. In World War Two, it is a fact that only 15-20 percent of the soldiers fired at the enemy. That is one in five soldiers actually shooting at a Nazi when he sees one. While this rate may have increased in desperate situations or with different units, in most combat situations soldiers were reluctant to kill each other. The Civil War was not dramatically different nor were any previous wars.

In WW2 only one percent of the pilots accounted for thirty to forty percent of enemy fighters shot down in the air. Some pilots didn’t shoot down a single enemy plane.  A very interesting statistic when you think about it.

In Korea, the rate of soldiers unwilling to fire on the enemy decreased and fifty five percent of the soldiers fired at the enemy. In Vietnam, this rate increased to about ninety five percent but this doesn’t mean they were trying to hit the target. In fact it usually took around fifty-two thousand bullets to score one kill in regular infantry units! It may be interesting to note that when Special Forces kills are recorded and monitored this often includes kills scored by calling in artillery or close air support. In this way SF type units could score very high kill ratios like fifty to a hundred for every SF trooper killed. This is not to say these elite troops didn’t score a large number of bullet type kills but it is interesting to note that most kills in war are from artillery or other mass destruction type weapons (airstrikes, mortars, naval gun fire, etc).

If one studies history and is able to cut through the hype, one will find that man is often unwilling to kill his fellow man and the fighter finds it very traumatic when he has to do so. On the battlefield the stress of being killed and injured is not always the main fear.

Fight, Flight, Posture or Submit

In the animal kingdom, most animals do not kill others of their species with very, very few exceptions. Humans are like animals in this regard, we don’t want to kill each other and sometimes we behave like animals, especially in combat.  Perhaps it is because when we look at another person on the field of battle if we are not careful we see that other person as someone like us, and ‘we’ do not want to die.

When animals confront each other they begin by posturing. They both attempt to intimidate the opponent into believing it is inferior and in danger. At this point they may fight, or one may submit or flee, and when they do fight it is very rarely to the death. When one submits it exposes some vulnerability to the enemy, like its throat.

Humans are not much different. Firearms are an excellent method of posturing, they are loud and dangerous, and the bullets zipping by overhead can be terrifying to the enemy. They provide a primal release when fired and can give the shooter a feeling of power. Posturing is very evident in combat tactics. War cries are a form of posturing. A battle cry cannot kill, but it provides a primal release and can intimidate the enemy. Bullets slamming into the ground or wall near a trooper can be frightening and when they are put there by some screaming ‘maniac’ it is much more terrifying.

This may be why so many rounds were fired in Vietnam without any real hits. (52,000 shots to score 1 hit? Our troops weren’t that bad at shooting!). US troops were in many cases superior at posturing. However, when it comes down to it, when the crunch comes, many people, regardless of how tough they sound in the barracks, find it hard to kill their fellow man and prefer to posture instead of kill.

Fire superiority means one side has postured successfully and has intimidated the enemy. In the Civil War there are cases where yelling matches have been held and the loser has retreated, simply because they were intimidated by the other side’s battle cries. (This happened in the woods where they couldn’t see each other but superior units retreated from inferior units because of effective posturing on the other side.)

The military does not recognize this as posturing, per se, they call it intimidating the enemy, or suppressing the enemy.

This does not mean all soldiers are trying to scare the enemy rather than kill him. A few may actively try to kill the enemy and this is where a great many of the casualties come from. Like the one percent of fighter pilots that killed forty percent of the total enemy killed.

Fighting is another option and then both sides will make an effort to kill each other. One side may submit, but for humans on the field of battle this is the most dangerous option because prisoners are often killed in the heat of battle, and not always on purpose! Fleeing becomes the best option and even this is very dangerous.  It is a natural animal response to hunt down and kill something that flees.  In a hostile situation someone that turns their back and runs triggers an almost instinctive response to be attacked.  Someone who surrenders in the heat of battle might not have given their opponent time to transition mentally from ‘predator fighting for its life’ to compassionate human who understands at a deeper more visceral level the fight is over and mercy can be shown.

Distance from the other human directly affects how easy it is to kill him. Bomber pilots don’t have trouble laying waste to kilometers of land and killing hundreds or thousands because they don’t see or hear the dead or dying. For infantry units, this takes on a different aspect, they see the fear in the other person’s eyes, the sweat on his brow, the pain in his face, the blood spurting from the wound, the desperate cries for help or mercy or their mother. The enemy becomes very real and vivid, the enemy becomes someone with hopes, dreams, fears, a mother, a father, maybe a wife, just like the shooter. In a way the shooter can see the enemy as little different than himself and killing that enemy soldier is like killing oneself. This is why infantrymen are more traumatized by war than any other field.

Wars are about humans fighting each other, it is horror and chaos, fear and trauma. This is why the shooting rate among troops is lower than most people would think. People will be willing to face death and dismemberment more willingly if they didn’t have to kill anyone. Medics for instance are notorious for risking life and limb to save someone while a regular trooper may stand by doing nothing but fire impotently at the enemy.

When a soldier flees he becomes a back. Again, humans are like animals. If you run from a dog it will chase you down and bite you, maybe kill you. Humans are like that, to run from a human high on adrenaline is an open invitation to be chased and killed. This is why the most dramatic casualties occur during a retreat. Troops no longer look into the eyes of a terrified foe like himself, he sees a back, prey that is fleeing from him and is much more willing and able to shoot him in the back. A fleeing soldier is no longer somebody, he is something, he is prey for the soldier behind him.

Killing a soldier that is submitting is a very frequent occurrence because the killer may be high on adrenaline, is in a highly emotional state and may not realize his foe is surrendering. Then there are the psychopaths that are quite willing to shoot down surrendering troops and these individuals are in every military.  It is after the battle when the soldier has time to rationalize and seeks to understand his actions that the horror becomes real.  This is one thing that can lead to PTSD.

To Kill or not to Kill

This is a very hard decision for a soldier to make and a great many factors can influence the soldiers ability to kill his fellow man. Before combat soldiers may talk a lot and seem like a blood thirsty, fear inspiring bunch. Veterans are likely to be more subdued unless they are ‘psyching themselves up’.

It should be noted that although a soldier may shoot, he may not try to kill. He may be ordered to fire but it is very hard to determine if he is trying to hit as can be noted by the 52,000 rounds fired for one hit ration in Vietnam. People were willing to fire but not always willing to hit the target. This can also be evident in earlier times when muskets were used when soldiers would get in a line, shoulder to shoulder, shoot each other and not hit anything. Even then some would not shoot.

Most sane humans, if given the choice, will not kill their fellow man and are extremely reluctant to do so, despite what holly wood would like you to believe. When they are forced to do so, many can experience a great deal of psychological trauma.

Superior training currently used by military organizations helps make the decision for the individual. This is a form of brainwashing but it is frequently necessary. In WW2 people learned to fire on a firing range at paper targets. When they got to the battle field they may have been excellent shots but they realized they were shooting at another person, someone named Hans or Frederick, or whatever. Today, more realistic targets are used in more realistic environments. Killing a ‘target’ becomes more automatic, more instinctive so when push comes to shove the trooper may be scared and unthinking, but his body knows what to do and does it, sometimes before the soldier can rationalize what he is doing. This makes the act of killing more traumatic for the killer and may be why a higher percentage of Vietnam vets suffer after the war. They had training which made them kill despite their desire and natural instinct not to.

Emotional and physical distance can also allow a person to kill his foe. Emotional distance can be classified as mechanical, social, cultural and emotional distance. Physical distance has to do with the distance. It is much more difficult to kill someone when you can feel his breath and see the fear in his eyes as you ram home a knife. It is very traumatic at such close range. At long range, like an artilleryman firing at the target that is over a couple hills, he does not see the enemy and can more easily deny the enemy’s humanity.

Emotional distance allows a person to kill at closer ranges and allows him to justify it more easily. Cultural distance is defined as viewing the enemy as an inferior life form. The enemy is dehumanized and considered inferior. Like the Nazi’s classified Jews and blacks as inferior and subhuman, putting them outside the human species and thus little more than an animal to be killed.

Moral distance is classifying the enemy as morally wrong. US troops fighting the Nazi’s or Japanese had moral distance to help them kill. The Nazi’s were butchers, cruel and vicious. The Nazi’s were guilty and had to be punished by those who were right and just.

Social Distance is a form of classifying others as lesser beings. For instance, in the medieval ages of Knights and men-at-arms, the Knights, the nobility were the primary killers. A soldier could look across the line at another soldier just like him, terrified and unwilling to kill. A Knight would look down at the serf/soldiers as lesser beings who simply could not compare to himself and their loss was not important because they were not as great as he was.

Mechanical distance is viewing the enemy through some device like a scope or on a screen. It allows the killer to dehumanize the target. Ships shoot at and destroy ships, and although they are killing other people, they don’t see it that way. Naval crews are more unlikely to suffer the psychological trauma of war for this reason. This is not to say they may not suffer, but they will not be reluctant to fire their weapon. Snipers see their target through a scope and this can make the enemy less (or more!) human to the shooter. In Desert Storm, the use of night sights made the war seem more like a Nintendo game.

Another factor that can a big effect on whether or not a person fires is the presence of authority. If an officer is standing next to a person and orders that person to fire, then that person is much more likely to do so. A Sergeant ordering his squad to fire will increase the fire rate. This is another point in argument for a fireteam because it allows a team leader to order his troops to fire and they will do so.

Other factors also have an effect on a soldier’s willingness to kill the enemy. Vengeance, hate and fear are all different factors that may enable a soldier to attempt to kill the enemy instead of just posture. Also letting down one’s fellows is an important factor because they rely on each other to keep them alive.

Battle Fatigue

Warfare is very traumatic, especially for front line troops that must face their reluctance to killing as well as being killed. It is much more frightening to have someone try to kill you with a knife than lob a bomb at you. You don’t see the fear and hate in a bomb’s eyes as he tries to insert a length of sharp metal into your body. The psychological casualty rate of front line units gave the Powers That Be, the idea of doing the same thing to enemy populations. In WW2 this became more evident as the nations bombed innocent, helpless civilians. It was believed that bombing them would cause a high number of psychiatric casualties for the enemy and destroy their will to fight, but it didn’t happen. In many cases it hardened their resolve instead of creating hordes of mentally traumatized people.

In this way, maneuver warfare is superior to attrition warfare because it strikes directly at an enemy’s will to fight. By violently attacking some rear area people begin to get frightened and realize that there is a threat of invasion and close up interpersonal aggression. The potential of close-up, inescapable, interpersonal hatred and aggression is more effective and has a greater impact on the morale of the soldier than the presence of inescapable, impersonal death and destruction. Officers are often buffered from enemy attack by ranks of soldiers that are defending them.

When an enemy attack destroys a headquarters unit, people realize that they are a target and the enemy is not interested in killing front line units. This can cause a great deal of psychological trauma for a battalion commander as he realized the enemy wants his head on a pike and is trying to get it. Living under this kind of threat can have a noticeable impact on people and because a front line soldier has to deal with this constantly he is more likely to become a psychiatric casualty.

Studies have shown that the more time in combat a soldier spends the more likely they are to become a psychiatric casualty. A psychiatric casualty is useless to a combat unit and presents as much danger to his fellows as the enemy. It is generally believed that sixty days of frontline combat will destroy a unit as an effective fighting force because after sixty days of combat ninety eight percent of the unit is likely to be a psychiatric casualty.

To prevent this, units are rotated back from the front to a relatively secure area. If the enemy has penetrated friendly lines and there is no ‘secure’ area then it is little different than being on the front. This might be another reason so many people suffered in Vietnam because there were no ‘front lines’ and no ‘safe’ areas.

Units are frequently rotated into the reserves to allow them time to ‘recover’.

To understand the ‘sixty day’ concept lets look at what happens when a unit goes into combat.

Within the first ten days a unit becomes ‘battlewise’, they become used to the demands of watching from every direction, they learn to deal with the enemy threat and they become more ‘undisturbed’ by what goes on around them. Between ten and thirty days, they reach maximum efficiency. The fall into the pattern of combat.

After about thirty days they may become over confidant and believe their efficiency is not decreasing when it is. Their bodies are running out of stored energy and the battle field environment is beginning to take its toll on more than just their mind. Combat exhaustion begins to set in. Combat exhaustion is the effect of the elements, poor food, and physical exhaustion. It also includes what happens to the body. When a human experiences an adrenaline rush there is a price to pay afterwards. Combat is like a roller coaster in this way with high’s being the adrenaline rush and lows coming after the rush. This ‘roller coaster’ affects a human body dramatically because of the highs and lows, and can be severely draining physically and emotionally.

After about forty-five days Emotional Exhaustion may set in and the unit’s efficiency decreases dramatically. Troops aren’t willing to attack, they are unwilling to dig fighting positions or run patrols. They lack the will they had before.

In WW2 the British believed their troops were good for one hundred days in battle before they became psychiatric casualties. This was made possible because they rotated the troops out of the battle zone every twelve days for four days of rest. US policy was to leave troops in combat for up to eighty days.

The ability to leave troops in combat like this has only become possible recently. In previous times, troops didn’t have the physical or logistic ability to support constant combat, but today they do.

Manifestations of Psychiatric Casualties

When a person becomes a psychiatric casualty this can take different forms of various degrees. After several months of combat nearly everyone will exhibit some symptoms of mental stress will appear. This does not mean they have gone completely bonkers and in some cases rest and recuperation helps a great deal. When it gets too bad there may be no easy solution. In some cases a person may exhibit symptoms to avoid battle. The way military units handle this is by treating as many people as possible as near to the front lines as possible.

Fatigue cases can best be described as the soldier becoming ‘tired’ and is unwilling to do anything. He doesn’t want to associate with friends or participate in any physical or mental activity or responsibility. He may be subject to sensitivity to loud noises, crying spells or fits of anxiety. In many ways all he wants to do is vegetate but he is subject to mood swings. The best way to cure this is to remove the person from the battle zone for rest and recuperation.

Confusional States are when a psychiatric casualty begins to lose track of time, place, and cannot deal with his environment. A person who was suffering from Fatigue can quickly shift into this state and become psychotic. Some symptoms include delirium, psychotic dissociation, and manic-depressive mood swings. Another possible effect is called the Ganzer syndrome. When a psychiatric casualty suffers from Ganzer syndrome he will make jokes, act silly or otherwise try to avoid the horror and fear with humor.

For instance a soldier may use a body or body part and treat it as still alive, like what the soldiers did to a dead body in Full Metal Jacket. They propped him up, put a cigarette in his mouth and ‘pretended’ he was alive. Some cases may become more extreme.

Conversion Hysteria can happen during combat or years later. This is a severe form if the Confusional state. The sufferer loses all touch with reality and may wander around regardless of dangers, like mines, enemy snipers, ect. The soldier may ball up into the fetal position and try to deny his surroundings or shake violently. Large portions of a person’s memory may be blocked out to protect the conscious mind from the horror. Another possibility is a certain portion of a person’s body may not function, like the arm that pulls the trigger.

Conversion Hysteria can appear in a soldier after being knocked out by a concussion, receiving some a minor wound or after a near miss. Hysteria can show up in the hospital or rear area. Sometimes it will appear when a soldier is told he must return and fight.

Anxiety States can affect a soldier’s ability to sleep. No matter how much sleep or rest he gets he is always tired. His dreams may be plagued by nightmares and the soldier may become obsessed with death. He begins to fear he may be a coward, he might fail his men or comrades or others might find out he is a coward. Some of the symptoms of anxiety are shortness of breath, weakness, pain, blurred vision, giddiness, temporary paralyzation and fainting.

Another effect of Anxiety disorders is called PTSD or Post Traumatic Stress Disorder. Years after combat the soldier’s blood pressure may rise dramatically along with sweating, nervousness and so on.

Obsessional and Complusive States are like Conversion Hysteria except the soldier is more aware of what is going on. The soldier understands that fear is causing everything but he cannot do anything about it. This can be manifested by uncontrollable tremors, palpitations, stammers, tics and so on. After a while the trooper may find some kind of hysteria that allows him to escape psychic responsibility for the physical symptoms.

Character Disorders are when a soldier becomes fixated on certain actions or things. Paranoia may include irascibility, depression and anxiety about his personal safety. Schizoids become hypersensitive and prefer to be alone. Epileptoid’s become more prone to violent and sometimes unpredictable rages. Some become obsessed with religion and some become psychotic. In essence a person’s very character has changed.


For more detail on they psychology of what goes on I highly recommend the book “On Killing” by Lieutenant Colonel Dave Grossman. The book is printed by Back Bay Books and goes into great detail on the different aspects of soldiers killing each other and killing in general. I would classify it as a must read.