For humans, killing is not easy, even when necessary to save our own lives. As humans, we all fear physical confrontations, even if they are necessary, such as during self-defense. In addition, we have an even greater fear of having to kill another human.
We all fear something, but a fear that can cause trauma, Post Traumatic Stress Disorder (PTSD), is the fear of close-range, person-to-person aggression. Fears of such things as heights or close quarters are considered a phobia or dysfunction but they do not cause trauma. Fear of death or injury is usually not sufficient to cause PTSD. An automobile accident may cause terrible physical injuries but most people do not suffer mental trauma merely because of the accident. However, many rape victims do, even though there was no physical injury.
More than anything else, intentional, overt, human confrontation has the greatest ability to modify and influence human behavior. In World War II, strategic and carpet-bombing caused much destruction and death but had little physiological effect on soldiers or civilians and did little to discourage the enemy’s will to fight. While the close-in artillery and hand –to-hand trench fighting of World War I and the machine gun attacks of the Korean War caused a large number of psychiatric casualties.
In close-in battlefield combat when bullets are flying, soldiers stop thinking with the forebrain (that portion of the brain which makes us human) and start thinking with the midbrain (the primitive portion of our brain which is indistinguishable from that of an animal). Animals viciously attack other species, but they resist killing their own kind. In conflict situations this primitive, midbrain processing can be observed in the powerful resistance of humans to kill other humans.
General Marshall, Official U.S. Historian of the European Theater of Operations in World War II, did post-combat interviews and found that that only 15 to 20 percent of the individual riflemen in World War II fired their weapons at an exposed enemy soldier. Crew-served weapons, such as machine guns, were almost always fired and firing greatly increased if a nearby leader demanded that the soldier fire. Other similar studies have shown that, when on their own, most individual combatants throughout history seem to have been unwilling to kill.
The US Army accepted Marshall’s conclusions and, instead of having trainees fire at bull's-eye targets, they used realistic, man-shaped, pop-up targets that fall when hit to help condition the men to killing. This type of conditioning is the only technique which will reliably influence the primitive, midbrain processing of a frightened human. Conditioning techniques increased the rate of fire to approximately 55 percent in Korea and to about 95 percent in Vietnam.
However, conditioning that overrides such a powerful, innate resistance to killing has enormous potential for psychological backlash. Every warrior society has a “purification ritual” to help the returning warrior deal with his guilt of killing and to reassure him that what he did in combat was good for society. In primitive tribes, this generally involves ritual bathing, ritual separation, and a ceremony embracing the warrior back into the tribe. Modern Western rituals traditionally involve long separation while marching or sailing home and then parades, monuments, and the unconditional acceptance of society and family once back home. After Vietnam, the purification ritual failed. Returning American veterans were attacked and condemned, which resulted in about a million cases of PTSD.
With the advent of interactive “point-and-shoot” video games, there is significant concern that society is aping military conditioning, but without the vital safeguard of discipline. There is strong evidence to indicate that the indiscriminate civilian application of combat conditioning techniques as entertainment may be a key factor in worldwide, skyrocketing violent crime rates.
As stated above, in a traumatic event, the midbrain takes control. Afterwards, it appears that a neural “shortcut” to the midbrain is created that mobilizes the body for survival in response to any “cue” associated with the traumatic incident. Physiological responses such as increased heart rate, respiration, and perspiration will occur for even the slightest of reasons and sometimes for no discernible reason whatsoever.
When our ancestors first heard a lion’s roar and dealt its subsequent attack, they learned to run when they heard the roar. Gradually, processing of the roar bypassed the forebrain and caused them to start running immediately, enhancing their chances of survival. Sometimes, not just the lion’s roar, but its smell or the crackling of brush would cause a reaction even if the person did not know what caused the reaction. Soldiers in combat soon learn to react reflexively to combat sounds and odors to insure their survival.
People fear things that seem to indicate that they are losing control of their minds. The midbrain’s bypassing of the forebrain can result in erratic, uncontrollable physiological reactivity. When this occurs, victims can become distressed by the sense that they are losing control of their minds. The physiological reactivity that occurs causes them to dread further incidents. Thus, their fear and physiological reactivity become enmeshed in a vicious cycle, which leads to PTSD.
In the past, soldiers "debriefed," by discussing their combat experiences every night around the campfire. Modern 24-hour combat for months on end prevents this ritual debriefing. Without the debriefings, PTSD cases increase, so systematic, scientific group discussions are now conducted to help soldiers relieve the stress of killing.
Killology. (2002). [Online]. Available: http://www.killology.com/article_onkilling.htm [2003, February 12].