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. Again, just the potential for close-up, inescapable, interpersonal confrontation is more effective and has greater impact on human behavior than the actual presence of inescapable, impersonal death and destruction. Indeed, 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 other human beings, even when defined as the enemy. Psychologists assert that this kind of powerful operant conditioning is the only technique that will reliably influence the primitive, midbrain processing of a frightened human being.
Fire drills condition schoolchildren to respond properly even when terrified during a fire.
Conditioning in flight simulators enables pilots to respond reflexively to emergency situations even when frightened. And similar application and perfection of basic conditioning techniques increased the rate of fire to approximately 55 percent in Korea and around 95 percent in Vietnam. Equally high rates of fire resulting from modern conditioning techniques can be seen in Holmes' observation of British firing rates in the Falklands and FBI data on law enforcement firing rates since the nationwide introduction of modern conditioning techniques in the late 1960s. The extraordinarily high firing rate resulting from these processes was a key factor in the American ability to claim that the United States never lost a major engagement in Vietnam. But conditioning that overrides such a powerful, innate resistance has enormous potential for psychological backlash.