In war, enemy fighters are three or four hundred yards away, and the bullets they are shooting cover that distance in about half a second – roughly two thousand miles an hour. Sound doesn’t travel nearly that fast, though, so the gunshots themselves arrive a full second after they were fired. Because light is virtually instantaneous, illuminated rounds – tracers – can easily be perceived as they travel toward you. The brain required two-tenths of a second just to understand simple visual stimuli, and another two-tenths of a second to command muscles to react. That’s almost exactly the amount of time it takes a high-velocity round to cover 400 yards.
Reaction times have been studied extensively in controlled settings and have shown that men have faster reaction times than women and athletes have faster reaction times than non-athletes. Tests with soccer players have shown that the “point of no return” for a penalty kick – when the kicker can no longer change his mind about where to send the ball – is around a quarter of a second. In other words, if the goalkeeper waits until the kicker’s foot is less than a quarter second from the ball and then dives in one direction, the kicker doesn’t have enough time to adjust his kick. Give that quarter-second cutoff, the distance of which you literally might be able to “dodge a bullet” is around 800 yards. You’d need a quarter second to register the tracer coming towards you – at this point the bullet has traveled 200 yards – a quarter second to instruct your muscles to react – the bullet has now traveled 400 yards – and half a second to actually move out of the way. The bullet you dodge will pass you with a distinctive snap. That’s the sound of a small object breaking the sound barrier inches from your head.
Humans evolved in a world where nothing moved two thousand miles per hour, so there was no reason for the body to be able to counter that threat, but the brain still had to stay ahead of the game. Neurological processes in one of the most primitive parts of the brain, the amygdala, happen so fast that one could say they compete with a bullet. The amygdala can process an auditory signal in fifteen milliseconds – about the amount of time it takes the bullet to go thirty feet. The amygdala is fast but very limited; all it can do is trigger a reflex and wait for the conscious mind to catch up. That reaction is called the startle, and it is composed of protective moves that would be a good idea in almost any situation. When something scary and unexpected happens, every person does exactly the same thing: they blink, crouch, bend their arms, and clench their fists. The face also sets itself into what is known as a “fear grimace”: the pupils dilate, the eyes widen, the brow goes up, and the mouth pulls back and down. Make that expression in front of a mirror and see not only how instantly recognizable it is, but also how it seems to produce a sense of fear. It’s as if the neural pathways flow in both directions, so the expression triggers fear as well as being triggered by it.
In a battle, veteran combat soldiers drop into a crouch. They don’t do this in response to a loud sound – which presumably is what evolution has taught us – but in response to the quieter snap of the bullets going past. The amygdala requires only a single negative experience to decide that something is a threat, and after one firefight every man has learned to react to the snap of bullets and ignore the much louder sound of men near them returning fire. After a second or two, the soldiers straighten up, begin shouting and taking cover. In those moments their higher brain functions decide that the threat requires action rather than immobility and everything ramps up: pulse and blood pressure to heart-attack levels, epinephrine and norepinephrine levels through the roof, blood draining out of the organs and flooding the heart, brain, and major muscle groups.
Veteran combat infantrymen will tell you, “There’s nothing like it, nothing in the world. If it’s negative twenty degrees outside, you’re sweating. If it’s a hundred and twenty, you’re cold as shit. Ice cold. It’s an adrenaline rush like you can’t imagine.”
The problem is that it’s hard to aim a rifle when your heart is pounding, which points to an irony of modern combat: it does extraordinarily violent things to the human body but requires almost dead calm to execute well. Complex motor skills start to diminish at 145 beats per minute, which wouldn’t matter much in a sword fight but could definitely ruin your aim with a rifle. At 170 beats per minute you start to experience tunnel vision, loss of depth perception, and restricted hearing. And at 180 beats per minute you enter a nether world where rational thought decays, bowel and bladder control are lost, and you start to exhibit the crudest sorts of survival behavior: freezing, fleeing and submission.
To function effectively, the soldier must allow his vital signs to get fully ramped up without ruining his concentration and control. A study conducted by the Navy during the Vietnam War found that F-4 Phantom fighter pilots landing on aircraft carriers pegged higher heart rates than soldiers in combat and yet virtually never made mistakes (which tended to be fatal.) To give an idea of the delicacy of the task, at one mile out the aircraft carrier is the size of a pencil eraser held at arm’s length. The plane covers that distance in thirty six seconds and must land on a portion of the flight deck measuring seven yards wide and forty-five yards long. The Navy study compared stress levels of the pilots to that of their radar intercept officers, who sat immediately behind them but had no control over the two-man aircraft. The experiment involved taking blood and urine samples of both men on no-mission days as well as immediately after carrier landings. The blood and urine were tested for a hormone called cortisol, which is secreted by the adrenal gland during times of stress to sharpen the mind and increase concentration. Radar intercept officers lived day-to-day with higher levels of stress – possibly due to the fact that their fate was in someone else’s hands – but on mission days the pilots’ stress levels were far higher. The huge responsibility borne by the pilots gave them an ease of mind on their days off that they paid for when actually landing the plane.
The study was duplicated in 1966 with a twelve-man Special Forces team in an isolated camp near the Cambodian border in South Vietnam. The camp was deep in enemy territory and situated to disrupt the flow of arms along the Ho Chi Minh Trail. An Army researcher took daily blood and urine samples from the men while they braced for an expected attack by an overwhelming force of Vietcong. There was a serious possibility that the base would be overrun, in which case it was generally accepted that it would be “every man for himself.”
The two officers saw their cortisol levels climb steadily until the day of the expected attack and then diminish as it failed to materialize. Among the enlisted men, however, stress levels were exactly the opposite: their cortisol levels dropped as the attack drew near, and then started to rise when it became clear that they weren’t going to get hit. The only explanation the researchers could come up with was that the soldiers had such strong psychological defenses that the attack created a sense of “euphoric expectancy” among them. “The members of this Special Forces team demonstrated an overwhelming emphasis on self-reliance, often to the point of omnipotence,” they wrote. “These subjects were action-orientated individuals who characteristically spent little time in introspection. Their response to any environmental threat was to engage in a furor of activity which rapidly dissipated the developing tension.”
Specifically, the men strung concertina wire and laid additional mines around the perimeter of the base. It was something they knew how to do and were good at it, and the very act of doing it calmed their nerves. In a way that few civilians could understand, they were more at ease facing a known threat than languishing in the tropical heat facing an unknown one.
What does all this have to do with Ceara Lynch?
The primitive amygdala driven adrenaline rush. Euphoric expectancy and fear of the unknown. The similarity between the bodies response to combat stress and a Dominant’s skilled manipulation of a submissive’s fear is striking, even if to a lesser degree.