A perhaps little known fact: in the olden days of war, people were way more reluctant to actually shoot at each other. In fact, only 15 to 20% of soldiers from the Civil War through WWII could bring themselves to raise a gun and actually point it at a fellow human being.
Then the military strategists got on board.
Here are a couple of articles on the sophisticated psychological training developed by the U.S. military to break soldiers down and enable them to go against the natural human instinct NOT to kill.
The first is entitled “On Killing: The Psychological Cost of Learning to Kill in War and Society.”
The second is called “Hope on the Battlefield.”
An excerpt from ““Hope on the Battlefield,” by Lt. Col. Dave Grossman:
“Indeed, the study of killing by military scientists, historians, and psychologists gives us good reason to feel optimistic about human nature, for it reveals that almost all of us are overwhelmingly reluctant to kill a member of our own species, under just about any circumstance.
Yet this understanding has also propelled armies to develop sophisticated methods for overcoming our innate aversion to killing, and, as a result, we have seen a sharp increase in the magnitude and frequency of post-traumatic response among combat veterans. Because human beings are astonishingly resilient, most soldiers who return from war will be fine. But some will need help coping with memories of violence. When those soldiers return from war—especially an unpopular one like Iraq—society faces formidable moral and mental health challenges in caring for and re-integrating its veterans….
Since World War II, a new era has quietly dawned in modern warfare: an era of psychological warfare, conducted not upon the enemy, but upon one’s own troops. The triad of methods used to enable men to overcome their innate resistance to killing includes desensitization, classical and operant conditioning, and denial defense mechanisms.
Authors such as Gwynne Dyer and Richard Holmes have traced the development of bootcamp glorification of killing. They’ve found it was almost unheard of in World War I, rare in World War II, increasingly present in Korea, and thoroughly institutionalized in Vietnam. “The language used in [marine training camp] Parris Island to describe the joys of killing people,” writes Dyer, helps “desensitize [marines] to the suffering of an ‘enemy,’ and at the same time they are being indoctrinated in the most explicit fashion (as previous generations were not) with the notion that their purpose is not just to be brave or to fight well; it is to kill people.”
But desensitization by itself is probably not sufficient to overcome the average individual’s deep-seated resistance to killing. Indeed, this desensitization process is almost a smoke screen for conditioning, which is the most important aspect of modern training. Instead of lying prone on a grassy field calmly shooting at a bull’s-eye target, for example, the modern soldier spends many hours standing in a foxhole, with full combat equipment draped about his body. At periodic intervals one or two man-shaped targets will pop up in front of him, and the soldier must shoot the target.
In addition to traditional marksmanship, soldiers are learning to shoot reflexively and instantly, while mimicking the act of killing. In behavioral terms, the man shape popping up in the soldier’s field of fire is the “conditioned stimulus.” On special occasions, even more realistic and complex targets are used, many of them filled with red paint or catsup, which provide instant and positive reinforcement when the target is hit. In this and other training exercises, every aspect of killing on the battlefield is rehearsed, visualized, and conditioned.
By the time a soldier does kill in combat, he has rehearsed the process so many times that he is able to, at one level, deny to himself that he is actually killing another human being” [italics mine].