Are Humans Innately Aggressive?

June 1988

Are Humans Innately Aggressive?

By Alfie Kohn

Sigmund Freud tried to cure Viennese women of their neuroses, and Konrad Lorenz made his reputation studying birds, but the two men shared a belief that has become lodged in the popular consciousness. The belief is that we have within us, naturally and spontaneously, a reservoir of aggressive energy. This force, which builds up all by itself, must be periodically drained off — say, by participating in competitive sports — lest we explode into violence.

This is an appealing model because it is easy to visualize. It is also false. As animal behaviorist John Paul Scott, professor emeritus at Bowling Green State University, has written: “All of our present data indicate that fighting behavior among higher mammals, including man, originates in external stimulation and that there is no evidence of spontaneous internal stimulation.” Clearly, many people — and, in fact, whole cultures — manage quite well without behaving aggressively, and there is no evidence of the inexorable build-up of pressure that this “hydraulic” model would predict.

The theory also predicts that venting aggressive energy should make us less aggressive — an effect known as “catharsis,” following Aristotle’s idea that we can be purged of unpleasant emotions by watching tragic dramas. But one study after another has shown that we are likely to become more violent after watching or participating in such pastimes. “Engaging in aggressive play just strengthens the disposition to react aggressively,” concludes psychologist Leonard Berkowitz, who is now writing a new book on the subject to complement his classic 1962 work, Aggression: A Social Psychological Analysis.

In 1986, a group of eminent behavioral scientists met in Seville, Spain, to discuss the roots of human aggression and concluded not only that the hydraulic model is inaccurate but, more generally, that there is no scientific basis for the belief that humans are naturally aggressive and warlike (see “The Seville Statement” following this article). That belief, however, has not been easily shaken. Among the arguments one sometimes hears are these:  Animals are aggressive and we cannot escape the legacy of our evolutionary ancestors; human history is dominated by tales of war and cruelty; and certain areas of the brain and particular hormones are linked to aggression, proving a biological basis for such behavior.  Let’s deal with each of these in turn.

The first thing to be said about animals is that we should be cautious in drawing lessons from them to explain our own behavior, given the mediating force of culture and our capacity for reflection. “Our kinship with other animals does not mean that if their behavior seems often to be under the influence of instincts, this must necessarily also be the case in humans,” says anthropologist Ashley Montagu. He quotes one authority who has written: “There is no more reason to believe that man fights wars because fish or beavers are territorial than to think that man can fly because bats have wings.”

Animals are not even as aggressive as some people think — unless the term “aggression” is stretched to include killing in order to eat. Organized group aggression is rare in other species, and the aggression that does exist is typically a function of the environment in which animals find themselves. Scientists have discovered that altering their environment, or the way they are reared, can have a profound impact on the level of aggression found in virtually all species. Furthermore, animals cooperate — both within and among species — far more than many of us assume on the basis of watching nature documentaries.

When we turn to human history, we find an alarming amount of aggressive behavior, but we do not find reason to believe the problem is innate. Here are some of the points made by critics of biological determinism:

* Even if a behavior is universal, we cannot automatically conclude it is part of our biological nature. All known cultures may produce pottery, but that doesn’t mean there is a gene for pottery making. Other institutions once thought to be natural are now very difficult to find. In a century or two, says University of Missouri sociologist Donald Granberg, “it is possible that people will look back and regard war in much the same way as today we look back at the practice of slavery.”

* Aggression, in any case, is nowhere near universal. Montagu has edited a book entitled Learning Non-Aggression, which features accounts of peaceful cultures. It is true that these are hunter-gatherer societies, but the fact that any humans live without violence would seem to refute the charge that we are born aggressive. In fact, cultures that are “closer to nature” would be expected to be the most warlike if the proclivity for war were really part of that nature. Just the reverse seems to be true. The late Erich Fromm put it this way: “The most primitive men are the least warlike and . . . warlikeness grows in proportion to civilization. If destructiveness were innate in man, the trend would have to be the opposite.”

Just as impressive as peaceful cultures are those that have become peaceful. In a matter of a few centuries, Sweden has changed from a fiercely warlike society to one of the least violent among industrialized nations. This shift — like the existence of war itself — can more plausibly be explained in terms of social and political factors rather than by turning to biology.

* While it is indisputable that wars have been fought frequently, the fact that they seem to dominate our history may say more about how history is presented than about what actually happened. “We write and teach our history in terms of violent events, marking time by wars,” says Temple University psychologist Jeffrey Goldstein. “When we don’t have wars, we call it the ‘interwar years.’ It’s a matter of selective reporting.”

*  Similarly, our outrage over violence can lead us to overstate its prevalence today. “Every year in the United States, 250 million people do not commit homicide,” Goldstein observes. “Even in a violent society, it’s a relatively rare event.” It is difficult to reconcile a theory of innate human aggressiveness with the simple fact that most people around us seem quite peaceful.

Many people have claimed that “human nature” is aggressive on the basis of having lumped together a wide range of emotions and behavior under the label of aggression. While cannibalism, for example, is sometimes thought of as aggression, it might represent a religious ritual rather than an expression of hostility.

The presence of some hormones or the stimulation of certain sections of the brain has been experimentally linked with aggression. But after describing these mechanisms in some detail, physiological psychologist Kenneth E. Moyer emphasizes that aggressive behavior is always linked to an external stimulus. “That is,” he says, “even though the neural system specific to a particular kind of aggression is well-activated, the behavior does not occur unless an appropriate target is available . . . [and even then] it can be inhibited.”

So important is the role of the environment that talking of an “innate” tendency to be aggressive makes little sense for animals, let alone for humans. It is as if we were to assert that because there can be no fires without oxygen, and because the Earth is blanketed by oxygen, it is in the nature of our planet for buildings to burn down.

Regardless of the evolutionary or neurological factors said to underlie aggression, “biological” simply does not mean “unavoidable.” The fact that people voluntarily fast or remain celibate shows that even hunger and sex drives can be overridden. In the case of aggression, where the existence of such a drive is dubious to begin with, our ability to choose our behavior is even clearer. Even if genes are fixed, the same does not necessarily follow for their behavioral effects. And even if “people are genetically disposed to react aggressively to unpleasant events,” says Berkowitz, “we can learn to modify and control the reaction.”

All of this concerns the matter of human aggressiveness in general. The idea that war in particular is biologically determined is even more farfetched. “When one country attacks another country, this doesn’t happen because people in the country feel aggressive toward those in the other,” explains Harvard University biologist Richard Lewontin. “If it were true, we wouldn’t need propaganda or a draft: All those aggressive people would sign up right away. State ‘aggression’ is a matter of political policy, not a matter of feeling.”

The point was put well by Jean Jacques Rousseau more than two centuries ago: “War is not a relation between man and man, but between State and State, and individuals are enemies accidentally.”

That states must “psych up” men to fight makes it even more difficult to argue for a connection between our natures and the fact of war. In the case of the nuclear arms race, this connection is still more tenuous. Says Bernard Lown, cochairman of International Physicians for the Prevention of Nuclear War, which received the Nobel Peace Prize in 1985: “The individual’s behavior, whether he’s aggressive or permissive or passive, is not the factor that makes up his outlook toward genocide. Even the person who’s aggressive won’t readily accept extinction.”


THE EVIDENCE, THEN, seems to indicate that we have the potential to be warlike or peaceful. Why, then, is the belief in a violent “human nature” so widespread? And what are the consequences of that belief?To begin with, we tend to make generalizations about the whole species on the basis of our own experience. “People in a highly warlike society are likely to overestimate the propensity toward war in human nature,” Granberg says. And the historical record shows the United States to be one of the most warlike societies on the face of the planet, having intervened militarily around the world more than 150 times since 1850. Within such a society, not surprisingly, the intellectual traditions that support the view that aggression is more a function of nature than nurture — such as the writings of Freud, Lorenz and the sociobiologists — have found a ready audience.

But there is more to it than that. We sometimes feel better, at least for a while, after acting aggressively, and this can seem to confirm the catharsis theory. The trouble is, says Berkowitz, “the fact that I reached my goal means that the behavior is reinforced, so in the long term I have an increased likelihood of behaving aggressively again” — for reasons that have more to do with learning than with instincts.

The mass media also play a significant role in perpetuating outdated views on violence, according to Goldstein. “If all one knows about aggression is what one sees on TV or reads in the newspaper,” he says, “what one knows is 19th-century biology.” Entertainment and news programming alike tend to favor Lorenz’s discredited model, confirming the notion that we human beings have a limitless supply of aggressive energy that must be discharged one way or the other.

Because it is relatively easy to describe, and because it makes for a snappier news story, reporters seem to prefer explanations of aggression that invoke biological necessity, Goldstein says. Wesleyan University psychologist David Adams, one of the Seville Statement organizers, got a taste of that bias when he tried to persuade reporters that the statement was newsworthy. Few news organizations in the United States were interested, and one reporter told him, “Call us back when you find a gene for war.”

Psychologist Leonard Eron of the International Society for Research on Aggression observes, “TV teaches people that aggressive behavior is normative, that the world around you is a jungle when it’s actually not so.” In fact, research has shown that the more television a person watches, the more likely he or she is to believe that “most people would take advantage of you if they got a chance.”

The belief that violence is unavoidable, while disturbing at first glance, actually holds a curious attraction for many people, both psychologically and ideologically. “It does have that ‘let’s face the grim reality’ flavor, which has a certain appeal to people,” says Robert Holt, a psychologist at New York University.

It also allows us to excuse our own acts of aggression by suggesting that we really have little choice. “If one is born innately aggressive, then one cannot be blamed for being so,” says Montagu. The belief, he maintains, functions as a kind of pseudoscientific version of the doctrine of original sin.

“In order to justify, accept and live with war, we’ve created a psychology that makes it inevitable,” Lown says. “It’s a rationalization for accepting war as a system of resolving human conflict.” To accept this explanation for the war-is-inevitable belief is simultaneously to realize its consequences. Treating any behavior as inevitable sets up a self-fulfilling prophecy: By assuming we are bound to be aggressive, we are more likely to act that way and provide evidence for the assumption.

People who believe that humans are naturally aggressive may also be relatively unlikely to oppose particular wars or get involved in the peace movement. Some observers insist that this belief functions only as an excuse for their unwillingness to become active. But others attribute some effect to the attitude itself. “The belief that war is inevitable leads people to rely on armament rather than working for disarmament,” says M. Brewster Smith, professor of psychology at the University of California, Santa Cruz.

There is some empirical support for this position. In a 1985 Finnish study of 375 young people, Riitta Wahlstrom found that those who considered war to be part of human nature were less inclined to support the idea of teaching peace or of personally working for it. David Adams and Sarah Bosch got similar results with a smaller study of U.S. college students. Forty percent said they thought war was “intrinsic to human nature,” and those students were slightly less likely than others to have worked on a peace-related activity.

Based on his own research during the Vietnam War, Granberg says, “If a war broke out tomorrow, the people protesting it would probably be those who did not believe that war is inevitable and rooted in human nature.” Those who do believe this are “more likely to accept the idea [of war] or at least unlikely to protest when a particular war occurs.”

The evidence suggests, then, that we do have a choice with respect to aggression and war. To an extent, such destructiveness is due precisely to the mistaken assumption that we are helpless to control an essentially violent nature. “We live in a time,” Lown says, “when accepting this as inevitable is no longer possible without courting extinction.”


PEACE ACTIVISTS can tell when it’s coming: Tipped off by a helpless shrug or a patronizing smile, they brace themselves to hear the phrase yet again. “Sure, I’m all in favor of stopping the arms race. But aren’t you being idealistic? After all, aggression is just” — here it comes — “part of human nature.”

Like the animals – “red in tooth and claw,” as Tennyson put it – human beings are thought to be unavoidably violent creatures. Surveys of adults, undergraduates and high school students have found that 60 percent agree with the statement, “Human nature being what it is, there will always be war.”

It may be part of our society’s folk wisdom, but it sets most of the expert’s heads to shaking. A number of researchers who have spent their lives working on the problem of aggression have concluded that violence, like selfishness, is “in human nature in the same way that David was in the marble before Michelangelo touched it,” in the words of psychologist Barry Schwartz of Tulane Medical School.

The problem is that most people are unaware of this scientific consensus. So two years ago, 20 scientists from 12 nations gathered in Seville, Spain, to hammer out a statement on the issue. The resulting declaration represents the wisdom of some of the world’s leading psychologists, neurophysiologists, ethologists and others from the natural and social sciences. It has since been endorsed by the American Psychological Association and the American Anthropological Association, among other organizations. The following are excerpts from the Seville Statement:

* It is scientifically incorrect to say we have inherited a tendency to make war from our animal ancestors. Warfare is a peculiarly human phenomenon and does not occur in other animals. War is biologically possible, but it is not inevitable, as evidenced by its variation in occurrence and nature over time and space.

* It is scientifically incorrect to say that war or any other violent behavior is genetically programmed into our human nature. Except for rare pathologies the genes do not produce individuals necessarily predisposed to violence. Neither do they determine the opposite.

* It is scientifically incorrect to say that in the course of human evolution there has been a selection for aggressive behavior more than for other kinds of behavior. In all well-studied species, status within the group is achieved by the ability to cooperate and to fulfill social functions relevant to the structure of that group.

* It is scientifically incorrect to say that humans have a “violent brain.” While we do have the neural apparatus to act violently, there is nothing in our neurophysiology that compels us to [do so].

* It is scientifically incorrect to say that war is caused by “instinct” or any single motivation. The technology of modern war has exaggerated traits associated with violence both in the training of actual combatants and in the preparation of support for war in the general population.

* We conclude that biology does not condemn humanity to war, and that humanity can be freed from the bondage of biological pessimism. Violence is neither in our evolutionary legacy nor in our genes. The same species [that] invented war is capable of inventing peace.

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