Torturers, rapists, murderers: for more than a decade as I researched my history of the Vietnam War, Kill Anything That Moves, I spent a good deal of time talking to them, thinking about them, reading about them, writing about them. They all had much in common. At a relatively young age, these men had traveled thousands of miles to kill people they didn’t know on the say-so of men they didn’t know, and for a mere pittance -- all of it done in the name of America.

I also spent time talking to another group of men, a much larger contingent who stood by and watched as those beside them tortured or raped or murdered. Some heartily endorsed these acts, some seemed ambivalent about them, some were appalled by them, but none did much of anything about them.

Then there was a third contingent of men: those who witnessed the torture, rapes, or murders and couldn’t -- wouldn’t -- abide by that conduct. This tiny group spoke out about what they had seen, often at the risk of their own welfare, sometimes their very lives.

What differentiated these men from each other? They had all been raised in the same country, had been subject to the same laws and norms, including prohibitions against torture, rape, and murder. Many, if not most, had grown up in similar socio-economic circumstances, received comparable educations, and at least nominally belonged to churches with strict moral codes and an emphasis on doing unto others as you would have them do unto you. Why then did so many of them commit horrendous acts or stand by while others did? Why did so few speak up?

I never came up with satisfactory answers to these questions. What I learned instead was that almost any man might be a torturer or a rapist or a murderer if given the chance. I learned that most men will look the other way if at all possible. And I learned that shockingly few men are capable of the courage and the empathy necessary to stand up for those that their brothers-in-arms would just as soon kill.

Today, Rick Shenkman -- head honcho at the History News Network and author of the just-published Political Animals: How Our Stone-Age Brain Gets in the Way of Smart Politics -- explores the biological phenomena that may well underpin our appalling lack of empathy, the animal instincts that allow so many of us to stand by in the face of unspeakable acts. While the science may still be in its early stages and the means of measuring our motivations still crude and inexact, Shenkman (whose new book Scientific American calls “a timely look into psychological patterns that drive political behavior”) analyzes a raft of studies that offer new ways of thinking about why so many humans tend to be so utterly inhumane, and explores how the stories we tell ourselves and others might offer us a path to overcome our utterly human inhumanity. Nick Turse

By almost any standard Cruz’s proposal was laughable and his rivals and the media called him on it. What happened next? By all rights after such a mixture of inanity and ruthlessness, not to say bloody-mindedness against civilian populations, his poll numbers should have begun to sag. After all, he’d just flunked the commander-in-chief test and what might have seemed like a test of his humanity as well. In fact, his poll numbers actually crept up. The week before the imbroglio, an ABC opinion poll had registered him at 15% nationally. By the following week, he was up to 18% and one poll even had him at a resounding 24%.

When CNN’s Wolf Blitzer objected that Cruz’s proposal would lead to lots of civilian casualties, the senator retorted somewhat incoherently: "You would carpet bomb where ISIS is -- not a city, but the location of the troops. You use air power directed -- and you have embedded special forces to direction the air power. But the object isn't to level a city. The object is to kill the ISIS terrorists." PolitiFact drily noted that Cruz apparently didn’t understand what the process of carpet (or “saturation”) bombing entails. By definition, it means bombing a wide area regardless of the human cost.

After Senator Ted Cruz suggested that the United States begin carpet bombing Islamic State (IS) forces in Syria, the reaction was swift. Hillary Clinton mocked candidates who use “bluster and bigotry.” Jeb Bush insisted the idea was “foolish.” Rich Lowry, the editor of National Review, tweeted : “You can't carpet bomb an insurgency out of existence. This is just silly.”

How to explain this? While many factors can affect a candidate’s polling numbers, one uncomfortable conclusion can’t be overlooked when it comes to reactions to Cruz’s comments: by and large, Americans don’t think or care much about the real-world consequences of the unleashing of American air power or that of our allies. The other day, Human Rights Watch (HRW) reported that, in September and October, a Saudi Arabian coalition backed by the United States “carried out at least six apparently unlawful airstrikes in residential areas of the [Yemeni] capital,” Sana’a. The attacks resulted in the deaths of 60 civilians. Just about no one in the United States took notice, nor was it given significant media coverage. More than likely, this is the first time you’ve heard about the HRW findings.

You might think that this is because the conflict in Yemen is off our national radar screen. But how much attention have Americans paid to U.S. air strikes and bombing runs in Iraq? Washington has literally been bombing Iraq on and off for twelve years and yet few have taken much notice. That helps explain why bombing is such an attractive option for Washington any time trouble breaks out in the world. Americans don’t seem to care much what goes on when our bombs or missiles hit the ground. As pollsters found recently, a surprising number of Americans even want to bomb places that can’t be found on a map. When Public Policy Polling asked GOP voters in mid-December if they favored bombing Agrabah, 30% said they did (as did 19% of Democrats), while only 13% opposed the idea. Agrabah is the fictional city featured in the Disney movie Aladdin.

Would you support or oppose bombing Agrabah?

Support bombing Agrabah…………………….. 30%

Oppose bombing Agrabah……………………… 13%

Not sure………………………………………………… 57%

That 57% were “not sure” might be considered at least modestly (but not wildly) reassuring.

Why Cruz’s Numbers Went Up

History suggests that this blanket bloodthirstiness or at least lack of empathy for those on the other end of America’s bombing campaigns isn’t new. In March 1951, nine months into the Korean War, Freda Kirchwey, a crusading liberal journalist at the Nation, expressed bewilderment at American indifference to the fate of Korean civilians killed by our bombs. The destruction was awful. Little was left standing, structurally speaking, in North Korea. Nothing, she complained in a column, “excuses the terrible shambles created up and down the Korean peninsula by the American-led forces, by American planes raining down napalm and fire bombs, and by heavy land and naval artillery.” And yet few seemed bothered by it.

Because she was an optimist Kirchwey expressed the hope that Americans would eventually come to share her own moral anguish at what was being done in their name. They never did. If anything, the longer the war ground on, the less Americans seemed interested in the fate of the victims of our bombing.

Why did they show so little empathy? Science helps provide us with an answer and it’s a disturbing one: empathy grows harder as distances -- whether of status, geography, or both -- increase. Think of it as a matter of our Stone Age brains. It’s hard because in many circumstances an empathic response is, in fact, an unnatural act. It is not natural, it turns out, for us to feel empathy for those who look different and speak a different language. It is not natural for us to empathize with those who are invisible to us, as most bombing victims were and are. Nor is it natural for us to feel empathy for people who have what social scientists call “low status” in our eyes, as did the Korean peasants we were killing. Recent studies show that, faced with a choice of killing a single individual to save the lives of several people, we are far more apt to consider doing it if the individual we are sacrificing is of such low status. When subjects in an experiment are told that high-status people are being saved, the number willing to let the low-status victim die actually increases.

Another social science finding helps us understand why empathy is often in short supply and why Ted Cruz is capable of cavalierly recommending we carpet bomb Syrians living under the control of the Islamic State. Once we have convinced ourselves of the necessity and correctness of bombing the hell out of a country -- as Americans did during the Korean War and as we are now doing in our war against IS -- the wiring in our Stone Age brain helps us overcome any hint of guilt we might be inclined to feel over the ensuing loss of life. It quite naturally acts to dehumanize the distant victims of our air strikes.

This is a classic case of cognitive dissonance. Our brain hates to feel torn between conflicting emotions. Instead it rationalizes doing what we want to do by discounting any feeling that gives rise to negative emotions, in this case, guilt. An extreme example of this was what happened when the Nazis decided to stigmatize Jews and later wipe them out. From the moment they began their ruthless anti-Semitic campaigns, they used hideous imagery to convince other Germans that Jews were not, like them, human at all, but little different than rats. It is, of course, far easier to kill someone, or to sit by while others do the same, if you dehumanize them first. Rather than feeling empathy for the downtrodden Jews, many Germans felt contempt and disgust, strong emotions that swamped whatever other feelings they might have had.

In a study a few years ago, researchers measured the activity in the brains of subjects looking at pictures of homeless people. The finding was shocking. Brain activity in the medial prefrontal cortex, the region of the brain where empathy is often registered, was significantly lower than normal. Put another way, the subjects in this experiment literally paid the homeless no (or at least less) mind.

This may sound cruel and uncaring, but as far as biology is concerned it makes sense. Our genes, as the biologist Richard Dawkins has taught us, are “selfish”; they are, that is, built to enhance their own replication, which is, in effect, their biological imperative. Caring for people who are low in status, particularly those who belong to another tribe, doesn’t serve this imperative. Indeed, it may interfere with it by diverting the attention of the host -- that’s you and me -- from activities that will enhance our survival.

Think of this as our Stone-Age brains in action. It’s not that we necessarily make a conscious decision to ignore the fate of people who are low in status. Our brain does this automatically and seamlessly for us. Out of conscious awareness it decides if someone is useful to us. If that person is, our brain quickly achieves a state of hyper-attentiveness: our nostrils flare, our eyes widen, and our ears tune in relevant sounds. Think of what happens when you’re in the presence of somebody important and you’ll know what I mean. If someone is deemed useless to us? Unless we’re worried that they hyperpose a threat, our brain tells our body to relax.

Because it is in our biological interest to feel empathy for people from our own tribe and family -- those, that is, in a position to either enhance our survival or perpetuate our genes -- we come equipped with mechanisms to help us distinguish our people from outsiders. From the moment we’re born, we focus on those around us and bond with them. A mother and child know each other through smell. Brother and sister recognize each other’s familiar facial features.

When we hear someone speaking a foreign language, we instinctively discount their humanity. This was shown in a 2014 experiment designed to determine if human beings were more willing to sacrifice someone who spoke a different language in order to save the lives of several others. The findings were clear-cut. Only 18% of the subjects in the experiment were willing to make the cold calculation that saving the lives of several people at the cost of one life was “fair” when the intended victim shared their native language. However, that percent more than doubled when it was revealed that the person to be sacrificed spoke a foreign language. The experiment’s results remained the same whether that language was Korean, Hebrew, Japanese, English, or Spanish.

Why Stories Matter When It Comes to American War

You may be beginning to wonder if we aren’t doomed to eternal indifference to the human beings who suffer when we loose our Air Force on them, but science offers us a modicum of hope on the subject. In recent years, one of the strongest findings is that storytelling can break through our indifference and foster empathy even for distant peoples who might otherwise seem alien to us. This more than anything else gives us the ability to empathize with those with whom we don’t identify demographically or otherwise. Stories hold our attention, while feeding the strong urge to find meaningful patterns in human behavior.

As scientists have now demonstrated in experiments, the brain is a natural pattern finder. It wants one and one to equal two. Mysterious may be the will of God, but here on Earth we expect behavior to be explicable. Stories are designed to establish cause and effect, and once we understand what motivates people we can usually find a way to empathize with them.

Stories connect us to people in a way nothing else can. It’s the reason politicians regularly tell stories on the campaign trail. Years ago, Harvard social scientist Howard Gardner set out to discover what highly successful leaders have in common. After reviewing the lives of 11 luminaries, from Margaret Thatcher to Martin Luther King, Jr., he concluded that their success depended to a remarkable extent on their ability to communicate a compelling story or, as he put it, “narratives that help individuals think about and feel who they are, where they come from, and where they are headed.” These stories, he found, “constitute the single most powerful weapon in the leader’s literary arsenal.”

When people are reduced to numbers -- as were the civilian victims of air power during the Korean War and as are the civilians who become “collateral damage” in American air strikes in Iraq, Syria, and elsewhere -- we don’t feel their pain, nor do we automatically put ourselves in their shoes, which is by definition what you do when you are feeling empathic. We have the bomber pilot’s syndrome. We don’t feel anything for the victims below.

This is one reason why antiwar movements matter. They tell stories about the victims of war. It was striking in the Vietnam years, for instance, how many Americans came to care for, say, a small naked Vietnamese girl napalmed near her village, or so many other Vietnamese civilians who suffered under a rain of American bombs, rockets, napalm, and artillery shells. The stories that the massive antiwar movement regularly told here about the distant world being decimated by the U.S. war machine created a powerful sense of empathy among many, including active-duty American soldiers and veterans of the war, for the plight of the Vietnamese. (It helped that few Americans believed that North Vietnam posed an existential threat to the United States. Fear brings out the worst in us.)

Storytelling happens to be in every human’s toolkit. We are all born storytellers and attentive listeners. Biology may incline us to turn a cold eye on the suffering of people we can’t see and don’t know, but stories can liberate us. Ted Cruz may be able to build up his poll numbers by promising to carpet bomb foreigners in the Middle East of whom we are fearful, but at least we know that biology doesn’t have to dictate our response. Our brains don’t have to stay in the Stone Age. Stories can change us, if we start telling them.

Rick Shenkman is the editor and founder of the History News Network and the author most recently of Political Animals: How Our Stone-Age Brain Gets in the Way of Smart Politics (Basic Books, January 2016).

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Copyright 2016 Rick Shenkman