An Author Explains How Mass Killings Happen

Starved prisoners, nearly dead from hunger, pose in concentration camp May 7, 1945 in Ebensee, Austria. The camp was reputedly used for
Photo: National Archives

Abram de Swaan spent his first years of life in the Netherlands, witnessing the horrors of World War II. After dedicating decades to the study of human behavior, the award-winning sociologist was so struck by the 1994 Rwandan genocide’s eerie resemblance to the systematic killings of the Holocaust that he decided to investigate the roots of mass murder. De Swaan’s new book, The Killing Compartments: The Mentality of Mass Murder, peers deeply into the minds of those who carry out atrocities, seeking to understand the societal and psychological conditions that give rise to mass murder.

From the destruction of the indigenous societies of South America by the Spanish to the horrific human-rights abuses of the current North Korean government, de Swaan shows that while every atrocity is different, both mass killings and those who commit them have certain commonalities that stretch across time and culture.

Science of Us recently spoke with de Swaan about his book and his research. 

Let’s start with what you refer to in your book as “the situationist consensus” — the theory that it is the situation and not personal disposition that makes a murderer. The Milgram experiment in 1961 and the Stanford prison experiment a decade later seemed to show strong evidence that situations can dramatically influence a person’s behavior, and perhaps his penchant for violence.
Often you hear the telltale phrase, You and I, under the same circumstances, might well have done the same thing, the idea being that almost everyone, under the right conditions, can be made to commit mass murder. First of all, you and I are happily not under the same circumstance, so that’s what you would call a counterfactual. We can never prove that the outcome is right or wrong. Second, if for a moment you want to realize what that is — “the same thing” — that is staggering. It is cold-bloodedly murdering people, not just one but dozens or hundreds of thousands. It is unimaginable. So it is also a counterintuitive idea.

In some ways, though, Milgram is certainly right, and that view has become the most stable consensus in the social sciences, of which there are very few. But there is more to be said about this. Some people simply would be more prone to commit deeds of murder than other people. Some people who get into that situation become eager killers and willing executioners, and others, they just try to do what they’re supposed to do, and try to do as little as they can. And still other people might simply not do it. In the Milgram experiment, one third of people refused to shock anyone!

There’s a story about an SS man who comes to Auschwitz and is supposed to take up guard duty there. He looks around and after an hour he says, “The son of my mother should not be here.” And so he goes. It’s moving — it’s what we all would like to be like. People are different. Even mass murderers are people, who differ from other people, who differ among one another. So let’s try to understand more of what’s going on in those souls and minds. 

What are the “killing compartments”?
Most literally, killing compartments are those shielded, secluded places where killing takes place — the killing fields. In a wider interpretation, they’re those zones in society where a targeted group is increasingly separated from the rest of the population. These targeted people are assigned to special schools and hospitals, and they have set curfews for when they must retreat to their assigned part of the town.

Because of this separation, the general population then often feels like [it] should avoid these people. You wouldn’t want to be seen talking to them, or you wouldn’t want to invite them to dinner, or your child’s birthday party. You feel a bit embarrassed or maybe even a bit scared when you get too close. And then they become compartmentalized even in your mind, in that they seem to be a very special kind of people … you sincerely feel uneasy with, or maybe you might even really feel you hate them. It’s an increasing separation at all levels — socially, culturally, the level of government and institutions, and of emotional and mental processes. 

What does anyone have to gain from creating such separations?
Well, usually there are sort of dormant, latent fault lines in a society that are only the basis for joking relationships. In New York, where many ethnic minorities deal with each other, you have to be a little careful. There’s a lot of joking going on, and you have to know exactly how to do it. In certain societies, though, you may get a politician who has the talent to change these fault lines into actual lines of division. If they’re successful, they can obtain the power of the state apparatus, this huge machinery of the state.

The people who man that state are called the regime. What’s in it for them? First, they may have won elections or mobilized big movements in the name of these mutual hatreds. And then, look, one person’s loss is another person’s profit. There are jobs to be had, houses to be taken; there is also the feeling that even though you may not be a big shot and a great success, at least you’re better than all those Xs, who, as we all know, are despicable, worthless people. So you may really have helped your self-esteem. There’s much to be had in such systems. 

Is it ultimately stemming from a place of insecurity, then?
“Ultimately” is difficult. Often people sow hatred for reasons of their own, like for electoral reasons or to ward off opposition. For example, you’re part of a group that’s very well-entrenched in society, but you feel threatened by, let’s say, landless day laborers. The day laborers start clamoring and making trouble, so you say to them, “Look, it’s not us, take those Xs, they’re really the cause of all your sufferings. It’s not us, we pay your wage!” It can be a very good way of uprooting a social movement. 

Which factors make an individual more likely to be capable of committing mass murder?
It’s like a probability distribution. Let me tentatively say that in at least three respects, perpetrators tend to be somewhat different from most people. Almost all mass perpetrators I know of think it’s very important to obey their commanders and to be loyal to their comrades. And surprisingly, they’re devoted family people. So they do have a conscience. But it’s a very restricted conscience, and anybody who is beyond that immediate circle doesn’t matter.

Secondly, generally, in the accounts of perpetrators you find very little overt, as the Americans call it, agency. A sense that you are an actor in your own life, and that your life is in part the consequences of what you decided to do. To them, life just occurs, it just happens to them. A famous Dutch man of letters once said about the SS, “They once and for all decided not to decide.”

The third thing, which is the most striking, is that these are people who feel no empathy and have no sympathy for anybody outside of their immediate circle. They don’t know what pity means. Sometimes they think they know what it means, when they’re in front of the judge and they say, “Oh, your honor, it was awful. I got all this blood on my uniform. And the shouting and crying of the victims was impossible to bear.” But it was impossible for them to bear, and it was their uniform. 

What kind of environment is conducive to that line of thinking?
Well, I talk about very different countries throughout the 20th century, ranging from Guatemala to Namibia to Cambodia, so it’s not so easy to say. But on the whole, most mass murderers are men, generally they’re young men, and, by the way, they’re healthy men. There is some evidence that when there’s unemployment and lack of opportunity, young men start drifting. And not only is there a material lack — they lack all sorts of things for themselves and their families — but it’s also very humiliating. You cannot find a wife if you have no income, and so it is very sexually frustrating. I would say young, unemployed men are a danger category. They are especially susceptible.

There may also be some idealism involved. Typical words of mass murderers are: “It’s now or never”; “It’s them or us”; and, “It’s all or nothing.” These complete dichotomies. You could almost sum up all of these ideologies into those six words. And then there is of course the feeling that you are better. That’s a marvelous feeling. 

How much do these factors apply to groups like ISIS and Boko Haram? Though they’re not the “regime in power,” it seems there could be some overlap with how they hope to entice young people to join their cause.
ISIS calls itself a state, but it is very difficult to say what it is. Wherever it comes in and is victorious, though, it behaves like many victorious armies. When an army is not controlled by its home front, when it feels that it has conquered a population and disarmed its opponents, when it’s in a rage because those opponents have threatened them and killed their buddies, and when they have the opportunity to do whatever they please, it goes into what I call a victor’s frenzy.

Part of that frenzy is not only plunder and arson but also rape and murder. And what ISIS does, they do it even more so than others, but it was a very common pattern in European and American colonial armies conquering new territory and burning villages. We all know the My Lai incident. It is a rather common pattern.

You also mentioned recruitment. That is a little bit different, because those people are being recruited in Europe nowadays. They are small, independent entrepreneurs, as common criminals are. Mass murderers often commit what is called a crime of obedience; they go with the flow of society. They march to the drum everybody else marches to. Common criminals go their own way, although they have friends and networks, but still, they do not go with the great mainstream of society. The ISIS people are a little bit in between. They often break with their parents, they form relationships with new friends, they form new networks with teachers and comrades, and then at some point they decide, alone or with one or two friends, to travel to Syria. That is different. 

When someone pledges allegiance to a group like ISIS, could it be because of some of the same mental processes that you link to an ability to commit mass murder?
Oh yes. And I have the impression that once you’re in there, it’s difficult to get out or to refuse to go along with the flow of utter murderous criminality. What is a little bit amazing about ISIS is that they flaunt their crimes. They display them ostentatiously, whereas colonial armies were discreet. Even the Nazis hid their crimes. They were very worried that they would be found out. 

That does seem to be a big dividing line between what we’re seeing now and what we’ve seen in the past.
ISIS figures that this may attract recruits and volunteers, and apparently it does. I can say that most people who say “I’m ready to die” really mean I’m ready to kill.

In the aftermath of genocide, the world has a tendency to say, “Never again, never forget.” But of course that’s often not the case. What is the best course for intervention, other than war?
I sincerely don’t know just how to do it. But I would be very careful in sowing hatred. It’s a biblical reference, thou shalt reap what thou have sown. To set up different groups in society against each other in a violent, vilifying manner is always a dangerous adventure because we are more or less condemned to live with one another, which is not always easy, but it is what we have to do.

And there is one very practical thing, and that is about this victor’s frenzy. You really have to train staff officers and say, “Look, be careful. When the mayor of the village doesn’t want to tell you where the remaining guerillas are, don’t start burning the whole place. Control yourself, because in this moment that you feel so victorious, you may commit crimes that you will be forever sorry for.” Sometimes this victor’s frenzy may completely intimidate people into a stupor of submission, and that is what ISIS tries. But again, there is one side against another. Don’t sow hatred.

This interview has been edited and condensed.

An Author Explains How Mass Killings Happen