Lt Col David Grossman has given OfficerResource.com permission to reprint some of his work. This is the first of three articles we are posting of his on the psychological effects of combat. -Xiphos
“Psychological Effects of Combat”
A Resistance to Killing
The kind of psychiatric casualties usually identified with long-term exposure to combat are notably reduced among medical personnel, chaplains, officers, and soldiers on reconnaissance patrols behind enemy lines. The key factor that is not present in each of these situations is that, although they are in the front lines and the enemy may attempt to kill them, they have no direct responsibility to participate personally in close-range killing activities. Even when there is equal or even greater danger of dying, combat is much less stressful if you do not have to kill.
The existence of a resistance to killing lies at the heart of this dichotomy between killers and nonkillers. This is an additional, final stressor that the combatant must face. To truly understand the nature of this resistance of killing we must first recognize that most participants in close combat are literally “frightened out of their wits.” Once the bullets start flying, combatants stop thinking with the forebrain, which is the part of the brain which makes us human, and start thinking with the midbrain, or mammalian brain, which is the primitive part of the brain that is generally indistinguishable from that of an animal.
In conflict situations this primitive, midbrain processing can be observed in the existence of a powerful resistance to killing one’s own kind. During territorial and mating battles, animals with antlers and horns slam together in a relatively harmless head-to-head fashion, rattlesnakes wrestle each other, and piranha fight their own kind with flicks of the tail, but against any other species these creatures unleash their horns, fangs, and teeth without restraint. This is an essential survival mechanism that prevents a species from destroying itself during territorial and mating rituals.
One major modern revelation in the field of military psychology is the observation that this resistance to killing one’s own species is also a key factor in human combat. Brigadier General S. L. A. Marshall first observed this during his work as the official U.S. historian of the European Theater of Operations in World War II. Based on his postcombat interviews, Marshall concluded in his landmark book, Men Against Fire, that only 15 to 20% of the individual riflemen in World War II fired their weapons at an exposed enemy soldier. Specialized weapons, such as a flame-thrower, usually were fired. Crew-served weapons, such as a machine gun, almost always were fired. And firing would increase greatly if a nearby leader demanded that the soldier fire. But when left to their own devices, the great majority of individual combatants throughout history appear to have been unable or unwilling to kill.
Marshall’s findings have been somewhat controversial. Faced with scholarly concern about a researcher’s methodology and conclusions, the scientific method involves replicating the research. In Marshall’s case, every available, parallel, scholarly study validates his basic findings. Ardant du Picq’s surveys of French officers in the 1860s and his observations on ancient battles, Keegan and Holmes’ numerous accounts of ineffectual firing throughout history, Richard Holmes’ assessment of Argentine firing rates in the Falklands War, Paddy Griffith’s data on the extraordinarily low killing rate among Napoleonic and American Civil War regiments, the British Army’s laser reenactments of historical battles, the FBI’s studies of nonfiring rates among law enforcement officers in the 1950s and 1960s, and countless other individual and anecdotal observations all confirm Marshall’s fundamental conclusion that man is not, by nature, a killer.
The exception to this resistance can be observed in sociopaths who, by definition, feel no empathy or remorse for their fellow human beings. Pit bull dogs have been selectively bred in order to ensure that they will perform the unnatural act of killing another dog in battle. Similarly, human sociopaths represent Swank and Marchand’s 2% who did not become psychiatric casualties after months of continuous combat, since they were not disturbed by the requirement to kill. But sociopaths would be a flawed tool that is impossible to control in peacetime, and social dynamics make it very difficult for humans to breed themselves for such a trait. However, humans are very adept at finding mechanical means to overcome natural limitations. Humans were born without the physical ability to fly, so we found mechanisms that overcame this limitation and enabled flight. Humans also were born without the psychological ability to kill our fellow humans. So, throughout history, we have devoted great effort to finding a way to overcome this resistance. From a psychological perspective, the history of warfare can be viewed as a series of successively more effective tactical and mechanical mechanisms to enable or force combatants to overcome their resistance to killing.