AS EUROPEAN colonists pushed slowly into the vast lands controlled by Amazonia’s indigenous tribes, they gradually exacted a grim toll on native peoples and their rainforest homes. Compulsory religious conversion, forced labor, environmental degradation, the introduction of deadly disease: each played a significant role in changing forever life along the banks of the world’s greatest river system.
One might expect that a review of this dark history would yield few if any points of light. But a new study by MU’s Robert Walker, an assistant professor of anthropology, has managed to accentuate at least one positive other scholars have overlooked. As part of a review of 11 previous studies, Walker found that before colonization Amazonian tribes appeared to be every bit as warlike as their European invaders — perhaps even more so. An astounding 30 percent of deaths among tribal society members resulted from violent conflict. And the good news? After colonization, he says, inter-tribal warfare declined precipitously. These days it is largely a non-issue. “Revenge was necessary in historical intertribal warfare, just as in modern gang conflicts, because showing weakness would result in further attacks,” Walker said.
“That cycle of revenge could result in tribes eradicating each other. After European contact, the dynamics of Amazonian tribal life changed dramatically. Although the spread of Christianity and imposition of national legal structures resulted in a great loss of cultural identity, it also reduced deadly raids. Today, such violence is rare.”
Walker’s study examined records from 238 historic clashes resulting in 1,145 violent deaths among 44 societies in the Amazon River basin. He analyzed each death to determine what cultural factors might have influenced the bloodshed.
Warfare among tribes with similar languages and cultures, he found, happened more frequently but left fewer fatalities than attacks on tribes of different language groups. Raids sometimes involved kidnapping women, a circumstance that tended to produce retaliatory violence. Treachery was also common. One tribe might invite a rival group to a feast, get them drunk and then attack. Predictably, such assaults resulted in high levels of mortality.
Walker draws a larger lesson from this mayhem, seeing in Amazonia’s former wars an “instinctual” pattern of aggression that even contemporary industrial democracies have yet to expunge. But he’s hopeful that, like the indigenous peoples in the Amazon, we might one day find our own formula for reconciliation. “Language and other cultural differences play a role in the 'clash of civilizations’ that resulted in recent violence, such as the deadly attack on the U.S. embassy in Libya and the continuing war in Afghanistan,” said Walker. “Working to develop a shared sense of humanity for all the earth’s people could help reduce major episodes of violence by encouraging people to view each other as one unified group working towards common global goals.”
Walker’s study was published online in the October 1 issue of Evolution & Human Behavior. Drew Bailey, a recent doctoral graduate in psychological science from MU, was co-author.