But, judging from comparisons of rates of combat deaths, modern nation states have not been as war-like as traditional tribal societies, according to Lawrence Keeley, professor of anthropology, University of Illinois, Chicago.
Isolating what causes a war is extremely difficult, said Keeley, who has studied cultural aspects of war. He noted that warfare increases and intensifies during "hard" economic times, or when the frontiers separating cultures are particularly violent. The presence of a warlike, aggressive society in the vicinity induces frequent warfare throughout a region.
Some researchers argue that war is about 10,000 years old while others contend that it is much older, maybe even millions of years old. Nearly every primitive society ever studied fought wars.
Stephen Beckerman, an associate professor of anthropology at Pennsylvania State University, noted that war is more frequent among tribal societies than is commonly believed, and most studies find that revenge is probably the single most common motive. The universal impulse to avenge an injury, harkening back to 'an eye for an eye, and tooth for a tooth,' is a driving force in human violence.
Beckerman examined revenge on both the individual and the social level. In both cases, revenge is often explicitly related to the deterrence of future aggression. People hold that an unavenged injury to self or kin gives permission for repetition of the injury. But ethnography also provides examples of revenge foresworn from fear of overwhelming counter-revenge.
Between close kinsmen, revenge is usually prohibited and an injury will go unmarked by any form of retaliation, Beckerman added. Social units that are relatively close but not related often take great care to balance deaths and to limit or end the hostilities. Tribal people often implement a socially regulated general system of reciprocity, including revenge, marriage and exchange of goods with a careful attempt to balance all losses and gains.
Among peoples who have the least connection of kinship, there is often unbridled blood revenge and often deliberate atrocity, he said. Exterminating the adversary may be the goal.
But revenge does not need a label to make it what it is, according to James Boster, an anthropology professor at the University of Connecticut. Boster studied the Waorani, a tribe in eastern Ecuador to examine if revenge is a cultural invention. Up until recent contact with the outside world, the Waorani engaged in a vicious cycle of revenge killings. The tribe's men responded to the death of a kin by attacking their enemies.
The Wao language lacks a term for the concept of "revenge killing," simply referring to the act as wænganta [killed] or tænongantapa [speared], he said. If killing is in revenge for another, the retaliatory nature is indicated by a simple juxtaposition. For example, 'Wewa bewitched Awa; we killed Wewa.' Apparently, a social pattern of revenge killing is not dependent on the recognition of 'revenge' as an abstract idea.
Boster noted that the absence of a Wao word for revenge is not unique, as very few complex concepts in the tribe's ethnopsychology are given a unitary label. Social breaches and their repair are seen as part of the meaning of what it is to be angry or calm, and may be sufficient explanation of a revenge killing. These features of Wao ethnopsychology can be interpreted as honest signals of human commitment to social contracts, he added.
Advance interviews possible upon request.
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MEDIA NOTE: Beckerman, Boster, Keeley and other researchers will participate in a session titled, "Tribal Warfare: Revenge, Retaliation, and Deterrence," during the AAAS Annual Meeting in Denver, at 8:30 a.m., Mountain Time, Friday 14 February, in Room A-A102-104 on the Main Level of the Colorado Convention Center. Press registration is located in the AAAS Press Center in Room C-101 of the Colorado Convention Center.