Former West Point psychology professor Lt. Col. Dave Grossman, has written extensively about theories on the psychology and physiology of deadly combat.

He found there were certain predictable physiological responses that occur in the body that are totally normal for that context, and they all happen automatically without you having to do really anything.

1. You need to poop.

One feeling that’s very common among soldiers preparing for combat is the urge to have a sit-down— or, as Grossman likes to say, “Take a battle crap.”

“In the lower abdomen in every human being is a toxic waste site,” he says. “The body’s response is to dump that toxic waste before a life and death event, because if there’s trauma to the abdomen that stuff will leak out and infect the wound. So, before the event, there’s often stress diarrhea.”

2. Blood flow to the body shuts down.

The moment battle starts, your body begins “vasoconstriction” which moves blood away from the body surface into the arteries and body core. That’s why your face goes white.

The redirected blood flow helps minimize bruising from blunt force trauma, and most importantly helps keep you alive long enough to finish the fight.

3. Your brain goes into “condition black.”

“As the blood drains from the face, blood drains from the forebrain, and there’s no rational thought,” Grossman explains. “I call that ‘condition black.’ And at condition black, the midbrain is in charge, and you’ll do what you’ve been trained to do — no more, no less. You will do what you’ve been programmed to do — no more, no less.”

Without adequate training, a soldier who reaches condition black may simply freeze up. But a well-trained soldier will spring into action to neutralize the threat.

“Given a clear and present danger, with today’s training almost everyone will shoot,” Grossman says.

4. You stop hearing the booms.

In the heat of battle, the nerve that connects the inner ear to the brain shuts down resulting in “auditory exclusion.” According to Grossman, 90 percent of combat soldiers report having experienced auditory exclusion. “You get caught by surprise in an ambush. Boom. Boom. Boom. The shots are loud and overwhelming. You return fire, boom. The shots get quiet, but you’re still getting hearing damage.”

5. Your vision narrows.

Most soldiers experience tunnel vision. “The charging lion is like a heat-seeking missile. He locks onto one target and never lets go,” he says. “That’s tunnel vision.”

Sometimes, however, instead of zeroing in on his target, a soldier becomes intensely aware of all the moving parts on the battlefield, like a wolf hunting with its pack. “That’s what we want,” Grossman says. “When I work with high level civilian operators, like LAPD SWAT, it’s amazing to see how they’ve evolved. Almost all of them move between these two models: zooming in to eliminate a target and then back out to see everything going on.”

6. You think of very strange things

The mind of a wounded soldier often envisions possibilities in the form of irrational thoughts or even hallucinations. This isn’t a psychotic episode, Grossman explains. It’s a survival mechanism.
“There was this police officer in Florida,” he says. “She was shot 10 times, and in the middle of this gunfight she says to herself, ‘I’m getting married in six months and you’re not going to stop me.’ And she killed the two bastards who shot her. She was back on the job a year later. So, yes, these are irrational thoughts, but at the same time, they’re motivating thoughts.”

7. You feel euphoria when it’s over – even if you’ve killed somebody.

“There are many ways people respond to combat, and there are many ways people respond to killing, and they’re all okay,” Grossman says.

One response is what he calls “survival euphoria” — the feeling of euphoria experienced after a life-or-death event, like an intense firefight. “It’s the body’s natural response: I’m alive. It’s the satisfaction of hitting the target like you’ve been trained to do under the stress of combat. You stopped a deadly threat. You saved your own life. You saved other lives. It’s okay to feel really good about it.”

8. Blood flow returns to normal – which can kill you.

On a physiological level after battle, the body relaxes and blood flow returns to normal – not good news is you’re wounded.

Goodman explains, “You’re finally triumphant. You won the battle. Then you relax and bleed out and die. So, it’s important to remember that the body will always backlash in the opposite direction. The wound that didn’t bleed out in the heat of battle will gush blood afterwards. That’s why today we immediately slap a tourniquet on the wound. People need to understand the importance of that.”

Of course, what happens to a soldier’s body and mind once they return from the battlefield is another thing entirely, but we’ll save that for another article.

(animated graphics created by Matt Battaglia)