Revenge: What is it good for? Studies of tribal warfare seek to answer why humans don't stop at 'an eye for an eye'

www.kmsb.com 03/10/2003 By SUSAN GAIDOS / Special Contributor to The Dallas Morning News

Some call it sweet, a few develop a thirst for it. Virtually everybody has plotted ways to get it.

Now scientists, too, are seeking revenge. Digging through anthropological and archaeological data on tribal warfare, researchers are analyzing the role that payback plays in human relations.

"Revenge is a peculiar topic," says Pennsylvania State University anthropologist Stephen Beckerman. "Everyone knows what it is, or thinks he does. Though there's a vast literature in theology and pop psychology urging us to eschew revenge and love our enemies, serious scholarly literature on revenge is remarkably thin."

Research so far suggests that when it comes to revenge, human intelligence "gone mad," perhaps, can spur people to do stupid things. And even when reason intervenes, human nature may urge you to strike back. Researchers say reciprocity, the give-and-take interchange that prompts you to return a favor, may also provoke you to repay a blow.

Revenge is not, of course, unique to humans. Animals share a universal impulse to strike back when injured. Studies show that a number of creatures – blue-footed boobies, elephant seals and side-striped jackals to name a few – routinely retaliate by attacking in kind. Evolutionarily speaking, revenge served up in this tit-for-tat fashion may serve an adaptive role by deterring future attacks.

Humans often carry revenge to lethal extremes, killing enemies for past actions and fueling feuds that can last generations. Yet given a warrior's dismal chances of surviving ongoing wars, the long-term benefits of revenge aren't so obvious.

So to better understand the interplay among revenge, retaliation and human motives, scientists are analyzing oral and written records on past tribal wars in New Guinea and Ecuador. Those studies may help explain how humans view conflict and may identify circumstances under which people are more likely to return violence for violence, anthropologists said in Denver last month at the annual meeting of the American Association for the Advancement of Science.

Lawrence Keeley, an anthropologist at the University of Illinois at Chicago who has studied warfare in modern and prehistoric societies, says tribal warriors, unlike their contemporary counterparts, attack their enemies for personal, rather than political or economic, reasons. Without governments to press them into service, these warriors go to war because they want to, not because they have to.

"Revenge and retaliation are a component of warfare everywhere and at all times," Dr. Keeley says, noting that revenge is motivated by injury whereas retaliation is returning injury for injury.

Studies of tribes in eastern Ecuador show that warriors may seek revenge for a variety of grievances or goals: A death, an illness, a streak of bad luck, even a desire for mates or glory can spark an attack.

But the No. 1 motive for coalitional violence is vengeance for a previous killing, says James Boster, an anthropologist at the University of Connecticut who has extensively studied Ecuador's Waorani tribes.

"The problem with retaliatory violence is that once started down the path of an attack and counterattack, the same furious dynamic that might have protected against the initial assault perpetuates the violence," Dr. Boster says.

Though the threat of retaliatory violence may deter an initial assault, once a fight breaks out it can lock antagonists into an endless cycle of violence, he explains.

Dr. Keeley agrees, noting that in the short term, retaliation can bring peace, albeit an uncomfortable one. Facing down opponents sends a clear signal of strength and sometimes forestalls further aggression.

But over the long haul, societies that seek revenge and retaliate most fiercely are also the most war-torn, he says.

Reciprocity role

Striking back may just be part of human nature, he says, noting that reciprocity, an inclination to return like for like, plays a role in all types of human interactions. Returning a favor, acknowledging a smile, reciprocity is a relational glue that helps build successful connections among families, friends and business associates.

"Reciprocity expresses a deep feature of human decision-making in action, and we can see it across human affairs everywhere," Dr. Keeley says.

Reciprocity also plays out in warfare, he says, operating under the guise of retaliation: an eye for an eye, a life for a life.

This type of exchange may account for the instinct to strike back when attacked, but it falls short of explaining why humans fail to put the brakes on lethal confrontation in the first place.

Paul Roscoe, an anthropologist at the University of Maine who has studied warfare in tribal societies of New Guinea, argues that human intelligence may be a conspirator, enabling man to play out his outrage. The same part of the brain that separates man from beast can be used to plan and organize attacks, he says.

Animals, lacking this "higher" intelligence, are too smart to carry revenge to such extremes.

Most animals are hard-wired to respond in kind to escalating aggressions, Dr. Roscoe notes, but they break off the confrontation – by withdrawing or submitting – when outmatched. Two male red deer, for example, will first roar at each other, and then walk back and forth to size each other up. Even if they lock horns and fight, the match is generally not lethal.

"The problem, in looking for a Darwinian theory of revenge, is to explain why humans, unlike most other species, don't stop short of lethality in their conflicts," Dr. Roscoe says.

"In the perfect case, a single retaliatory homicide would pay the blood debt and end the matter. At most, one or two reciprocal homicides would suffice for both sides to get the message and either cease hostilities or for one side to withdraw."

Anthropological data from New Guinea show, however, that revenge and retaliation are seldom this efficient. A fracas that results in a single death can set into motion a seemingly endless cycle of attacks and counterattacks. Because warring parties often disagree on what constitutes a balance of killings, feuds may endure for years or generations once started.

In describing their motives for killing, the tribal members expressed a desire to "even the score." One tribe, for example, said, "The clan has been weakened, thus the clan of the murderer must be weakened, too." Another said it would fight until the number of the dead ones was fairly even, to "keep the enemy balanced in terms of manpower."

Fear factor

New Guinea warriors also killed out of fear for their own well-being. Believing failure to vindicate a homicide would bring sickness and death to its members, the Iatmul tribe would promptly avenge a killing.

Similarly, the Melpa were quick to take vengeance, believing that the spirit of a murdered man would "pester his own clan until he was avenged."

Dr. Roscoe concludes that blood revenge is probably not a useful evolutionary adaptation. It frequently fuels more killing rather than deterring it, he says.

He argues that war is a "byproduct of human intelligence," an outgrowth of man's highly developed neocortex. The neocortex, a region of the brain known for intellectual thought and creativity, enables humans to develop tools, communicate through language and plan and carry out group action for war.

"Humans developed the ability to model actions before they happen. This means we can plan collective violence. It explains why we have warfare," Dr. Roscoe says. Research on chimps confirms that once you can gang up and launch a surprise attack on outnumbered victims, killing becomes a dramatically more attractive option.

Neocortical prowess also allows humans to dehumanize their enemies and manipulate their emotional states, says Dr. Roscoe. Warriors, for example, can whip themselves into an angered frenzy by recalling slain kin and engaging in repetitive, war-mongering chants.

But if tribal warriors sometimes use their intelligence to incite war, evidence shows they also use it in ways to forestall aggression and set limits on reciprocal violence.

Dr. Beckerman, of Penn State, notes that tribes in many places develop elaborate rules outlining who, where, when and how revenge may be carried out. Kin, for example, are forbidden to retaliate against each other.

"The general rule is that you are prohibited from taking blood revenge on those who would be obliged to avenge you, if you were killed," Dr. Beckerman says.

Groups with ongoing relations – such as different clans within the same tribe or different villages within the same precinct – often share ideas on what kind of injury calls for blood revenge, who should carry it out and who the acceptable target of revenge ought to be, he says.

And reciprocity, the same relational rationalization used to return violence for violence, is sometimes used to build truces and contain unbridled violence. Food, labor, wives and other goods are often traded among members of tribes or between groups in attempts to keep losses and gains in balance or to bring an end to bloodshed.

"A life for a life, an eye for an eye, a tooth for a tooth was not, for the tribal people who codified this rule, a recipe for unbridled violence, but rather an attempt to contain it," Dr. Beckerman says.

Scientists note that these are not the only factors that play into war. Brian Ferguson, an anthropology professor at Rutgers University in Newark, N.J., who has studied the Yanomami Indians of Venezuela and Brazil, notes that revenge as a concept differs from one society to another, and no one revenge model fits all.

Ultimately, such studies may provide insights on warfare among larger societies and states, Dr. Roscoe says. "Personally, I think we have an awful lot to learn from areas like New Guinea, because we're not looking back in the past, but we're looking at ourselves in the present, stripped of our thermonuclear weapons."

Susan Gaidos is a free-lance writer in Maine.