Jared Diamond on vengeance

In the current New Yorker, anthropologist Jared Diamond, author of Guns, Germs, and Steel and Collapse, looks at the vengeance practices of tribal societies in New Guinea. While Diamond was conducting field work in the New Guinea Highlands, he was driven around by a young man named Daniel Wemp of the Handa clan. The two got to talking and Daniel recounted how he avenged the death of his uncle who had been killed by the neighboring Ombal clan. The tale is amazing, insightful, and gets you thinking about our own, er, taste for revenge. From the New Yorker article, titled "Vengeance Is Ours":

The war between the Handa clan and the Ombal clan began many years ago; how many, Daniel didn't say, and perhaps didn't know. It could easily have been several decades ago, or even in an earlier generation. Among Highland clans, each killing demands a revenge killing, so that a war goes on and on, unless political considerations cause it to be settled, or unless one clan is wiped out or flees. When I asked Daniel how the war that claimed his uncle's life began, he answered, "The original cause of the wars between the Handa and Ombal clans was a pig that ruined a garden." Surprisingly to outsiders, most Highland wars start ostensibly as a dispute over either pigs or women. Anthropologists debate whether the wars really arise from some deeperlying ultimate cause, such as land or population pressure, but the participants, when they are asked to name a cause, usually point to a woman or a pig. Any Westerner who knows the story of Helen and the Trojan War will not be surprised to hear women named as a casus belli, but the equal importance of pigs is less obvious. However, New Guinea Highlanders, whose main food staples are starchy root crops like sweet potato and taro, are chronically starved for protein, of which the island's dark, bristly pigs traditionally furnished the only large source. As a result, pigs are prized symbols of prestige and wealth. Peaceful competition and ostentatious displays involve pigs, and they are also used as currency for buying women. Pigs are individually owned and named, and, as piglets, they are sometimes nursed at one breast by a woman nursing an infant at her other breast.

A typical Highland village is a cluster of huts housing between a few dozen and a few hundred people plus their pigs, traditionally surrounded by a fence, and situated a mile or a few miles from the next village. A village's pigs are taken out to forage during the day, and are prone then to wander into people's vegetable gardens, breaking down or digging under fences erected to keep them out. A single pig can root up and ruin an entire garden in a few hours. If the intrusion happens at night, or if the offending pig is not caught in the act, it is virtually impossible to prove which particular pig was responsible.

That was how the Handa-Ombal war began. An Ombal man found that his garden had been wrecked by a pig. He claimed that the offending pig belonged to a certain Handa man, who denied it. The Ombal man became angry, demanded compensation, and assaulted the Handa pig owner when he refused. Relatives of both parties then joined in the dispute, and soon the entire membership of both clans–between four and six thousand people–was dragged into a war that had now raged for longer than Daniel could remember. He told me that, in the four years of fighting leading up to Soll's death, seventeen other men had been killed.