Rumble in the Jungle

A bitter scientific dispute erupts around the Yanomami Indians

Napolean A. Chagnon got a rude shock when he first trekked through the Venezuelan rainforest to a Yanomami village in 1964. The aspiring anthropologist expected that the then-obscure Amazonian natives would gladly describe their family histories and marriage practices.

A Yanomami man demonstrates how to use his super-sized bow and arrow. Photos: E. Migliazza

Jacques Lizot, left, and Napolean Chagnon pose in the Venezuelan jungle in 1968.

James Neel administers a measles vaccine to a Yanomami Indian in 1968.

Instead, a dozen naked men immediately surrounded Chagnon and a colleague, aiming drawn arrows at the horrified pair. Strands of dark-green mucus drizzled from the bowmen’s noses, the remains of a hallucinogenic powder that they had just sniffed. At the same time, a pack of snarling dogs snapped at the visitors’ legs and tore their trousers.

Chagnon survived that scary encounter and gained fame as the investigator who dubbed the Yanomami “the fierce people” for their violent ways. However, the University of California, Santa Barbara anthropologist now faces a different kind of threat, one that could well make him look back fondly on the day he only had to contend with armed warriors and vicious canines.

In his book Darkness in El Dorado (2000, W.W. Norton), journalist John Tierney shoots a quiverful of literary arrows at the heart of Chagnon’s scientific integrity. Among Tierney’s charges: Chagnon covertly staged incidents shown in famous films of the Yanomami, stirred up Yanomami warfare with his research tactics and reported on their violence in deceptive ways, conspired with others to gain control of the Yanomami’s land so that he could ensure research access to them, and codirected what has become a controversial vaccination program that sparked a deadly measles epidemic among the Yanomami.

Tierney takes aim at other investigators as well. They include the late University of Michigan geneticist James Neel, who headed the Yanomami vaccination program with Chagnon in 1968, and University of Paris anthropologist Jacques Lizot, who allegedly used Western goods to buy sexual favors from Yanomami boys during his own field work.

The media also fare poorly in Tierney’s book. In his account, journalists accompanied Chagnon on helicopter flights to Yanomami villages that blew the roofs off structures and left behind injured, frightened residents. Soon after these trips, news reports promoted Chagnon’s research without mentioning these incidents.

In another media travesty recounted by Tierney, a documentary crew filmed the progressive weakening and death from fever of a Yanomami woman and her infant without making any attempt to provide medical care to them. Their acclaimed documentary was shown on television in 1996 as a NOVA/BBC special.

Talk of the anthropological world

For weeks before the publication of Tierney’s book last November, these and other allegations were the talk of the anthropological world and fodder for worldwide news reports. Much of the furor followed the widespread dispersal of an E-mail message sent in June to American Anthropological Association (AAA) officials by Terry Turner of Cornell University, and Leslie Sponsel of the University of Hawaii in Honolulu. Turner and Sponsel outlined Tierney’s accusations after reading galley copies of his book and concluded that the author’s revelations “should shake anthropology to its very foundations.”

At the very least, his allegations have turned Tierney into a target of vitriolic criticism. With charges of inaccurate and untrustworthy reporting, a growing band of critics has rattled Tierney’s evidence for epidemic-inducing vaccinations and for the filming of staged Yanomami behavior. Some of these critics suggest that Tierney, whose book was excerpted in the Oct. 9, 2000 New Yorker and has been nominated for a National Book Award, either concocted a hoax or has been duped by missionaries living near the Yanomami and who have long clashed with Chagnon.

Whichever way the charges and countercharges pan out, nearly everyone agrees that Chagnon can muster his own brand of ferocity. He has made enough enemies in and out of academia over the past 35 years for his supporters to denigrate Tierney’s work simply as the latest episode of “Chagnon bashing.”

Anthropologists also concede, however, that this altercation grew out of much deeper divisions in their discipline. One chasm concerns the nature of human nature. Chagnon’s arguments exemplify those now championed by a scientific movement known as evolutionary psychology. A central tenet of this camp’s proponents is that a considerable number of biological dispositions evolved during the Stone Age, including a male propensity for making war.

But many researchers, including Sponsel, argue that cultural and historical factors lie at the root of warfare. How else, they ask, can the existence of so many peaceful hunting and foraging groups be explained?

Another rift that Tierney’s book has brought to the fore concerns the nature of anthropology as a discipline. Chagnon represents researchers who view experienced fieldworkers as data collectors in pursuit of objective truths about people. Many of his detractors view fieldwork as inherently subjective and open to interpretation, although still within the realm of science. A more radical movement in cultural anthropology regards fieldwork not as a technique of science but as only personal storytelling by an observer.

“I understand the grief and anger over my book,” Tierney says. “I hope everyone can work together, and we can make some light from this darkness.”

Do no harm

Tierney spoke those words on Nov. 16, 2000, to a packed house at a special session of the AAA annual meeting, held in San Francisco. Several speakers had just attacked his book, especially its claim that Neel and Chagnon’s vaccination practices triggered a measles epidemic among the Yanomami.

The same day, AAA officials established a task force to determine by Feb. 1 whether the organization should investigate Tierney’s charges. They also launched an effort to develop specific ethical guidelines for anthropologists on issues such as how to obtain informed consent of research subjects and when to seek medical help for them.

Anthropologists in the field currently operate on the general principle of “Do no harm,” according to AAA President Louise Lamphere of the University of New Mexico in Albuquerque.

The day after the AAA’s special session, a representative of Venezuela’s Office of Indigenous Affairs announced at the meeting that his organization had established its own commission to investigate Tierney’s charges. The official has also stopped issuing research permits until the same commission drafts regulations for scientists on ethical practices and informed consent with native Venezuelan groups.

Chagnon has distanced himself from the whole affair and didn’t attend the AAA meeting. In statements on his Web site, Chagnon calls Tierney’s accusations “preposterous” and part of a longstanding campaign that Turner and Sponsel have orchestrated to halt his research. Turner and Sponsel deny that accusation.

Chagnon’s friend William Irons, an anthropologist at Northwestern University in Evanston, Ill., represented him at the San Francisco meeting. Irons added another level of intrigue by pointing out that Tierney traveled among the Yanomami with the help of Catholic Salesian missionaries who have openly opposed Chagnon’s research.

Chagnon has previously argued that the Salesians’ efforts to move Yanomami close to mission stations has increased deaths from infectious diseases. Missionaries also have supplied Yanomami with shotguns that Chagnon claims have intensified the brutality of wars between villages.

Although no official verdict on Tierney’s claims is in, separate reports by academic parties with their own interests in the controversy—the National Academy of Sciences, the University of Santa Barbara anthropology department, and a committee of University of Michigan scholars—appeared shortly before the AAA meeting. The prime target of these probes is Tierney’s claim that Neel and Chagnon inoculated Yanomami individuals with a vaccine that set off a 1968 measles epidemic. Each report comes down harshly on at least some of Tierney’s conclusions.

In Tierney’s scenario, Neel worked for a scientific arm of the U.S. Atomic Energy Commission (AEC). As part of its genetic studies of Japanese survivors of atomic blasts and people living near sites of atomic bomb testing, the AEC wanted to use the Yanomami as a comparison population with no history of radiation exposure, Tierney says.

As Neel and Chagnon collected Yanomami blood samples and administered measles inoculations in 1968, a measles epidemic broke out in the region, Tierney says. A solid explanation for this concurrence remains elusive, but Tierney points to the researchers’ curious use of a vaccine known as Edmonston B, which was no longer the vaccine of choice in the United States. Edmonston B vaccine was known to cause severe reactions even among city-dwellers with far greater measles resistance than the Yanomami, Tierney argues. The vaccine may have initiated measles in the relatively isolated population, in his view.

Furthermore, Tierney charges that Neel and Chagnon wanted to observe an epidemic among a genetically isolated group and so failed to get medical help for measles sufferers.

A statement issued on Nov. 9, 2000, by Bruce Alberts, president of the National Academy of Sciences (NAS) in Washington, D.C., disputes Tierney’s account. First, Neel’s vaccination work was performed under the auspices of the NAS, not the AEC, Alberts says. Second, research has shown that Edmonston B is safe and doesn’t cause measles to appear or spread.

Mark Papania of the Centers for Disease Control in Atlanta and other vaccine experts agree with Alberts that a measles epidemic can’t be triggered by Edmonston B vaccinations.

The Michigan and Santa Barbara investigations further note that Neel’s field notes describe the provision of medical care, which probably held down death rates during the epidemic.

Tierney also attempts to discredit Neel as a supporter of eugenics. Neel held the “eugenic” view that in small tribal societies, fights among headmen over women have promoted the survival of leadership- or dominance-related genes, Tierney says. These genes haven’t fared well in modern societies where the physically weak benefit from advanced medical care and social programs, Neel suggested.

The NAS statement counters Tierney’s charge. Neel was a respected geneticist who never advocated eugenic policies such as forced sterilization; instead, he preached the value of enriched environments to foster each person’s inherent potential, Alberts says.

Staged scenes

In his book, Tierney concludes that Chagnon staged scenes of a Yanomami feast and an axe fight in films that he produced with the late ethnographic filmmaker Timothy Asch. According to Tierney, unedited footage saved by Asch documents behind-the-scenes manipulations. Recordings of discussions, he argues, reveal the filmmakers’ intent to avoid mention of the rash of disease and death that swept through the Yanomami after the arrival of outsiders.

Documentary filmmakers familiar with Asch’s work counter that claim. According to the Michigan probe, which incorporated analyses by such filmmakers, there is no evidence of staging or behind-the-scenes coaching in any of the Yanomami films.

Tierney also charges that Chagnon participated in a scheme during the early 1990s to set up and control a Yanomami land preserve that would have guaranteed him long-term access to its inhabitants without having to negotiate for such rights with Venezuelan officials.

Chagnon’s alleged accomplices were Charles Brewer-Arias, a long-time colleague and naturalist whom Tierney says wanted to pursue tin mining in the region, and Cecilia Matos, who, as mistress of Venezuela’s former president, headed a foundation that would have funded the preserve.

That and other charges, such as the alleged sexual exploitation of Yanomami boys by the University of Paris’ Lizot, await further investigation.

A fierce people

From a scientific vantage point, the crux of Tierney’s brief against Chagnon centers on Yanomami warfare. In an influential 1988 paper, Chagnon offered chilling evidence for his characterization of the Yanomami as a “fierce people” for whom adept killing of rivals during warfare pays off, at least for men, with more offspring.

About 40 percent of adult males had participated in a killing during a raid on another village, and 30 percent of deaths among adult males had been due to such violence, he reported. Yanomami men received a ritual purification and became known as unokais after participating in a killing. Unokais had more than twice as many wives and more than three times as many children as other men did.

To challenge Chagnon’s thesis, Tierney invokes an analysis in the book Yanomami Warfare: A Political History (1995, Santa Fe: School of American Research Press) by anthropologist R. Brian Ferguson of Rutgers University in Newark, N.J.

Ferguson argues, for example, that unokais include not only actual killers but also men who conduct rituals intended to kill enemies through magic and who shoot arrows into already dead enemies. Moreover, Ferguson holds that the fiercest warriors can’t father many children because they often die in revenge killings.

Chagnon avoids this complication by omitting the dead fathers of living children from his Yanomami analysis, Ferguson said in an interview.

Archaeological evidence gathered throughout the world suggests that wars occurred occasionally during prehistory but have flared up more regularly only over the past 10,000 years or so, Ferguson says. Western contact and state expansion have often intensified native warfare, he theorizes.

Tierney’s reconstruction of Yanomami battles, based on interviews with participants, supports Ferguson’s proposal. Chagnon used machetes and other goods to extract genealogical information—often about relatives of those in neighboring villages—from people whose belief system prohibited them from uttering the names of dead ancestors. In the process, he created competition for his favors and antagonism between villages that triggered warfare, Tierney argues.

In short, Ferguson points to a mix of Western intrusions as the reason for intensified warfare among the Yanomami. He includes Chagnon, the Salesian missionaries, and the influx of gold miners in Yanomami territory over the past 20 years.

Other scientists, including anthropologist Kim Hill of the University of New Mexico, take issue with that analysis and bolster some of Chagnon’s claims. Accounts of intense Yanomami warfare by ethnographers other than Chagnon, for example, make no mention of fighting over metal tools or other Western goods, he says.

In Hill’s analysis of Paraguay’s Ache Indians, which he conducted with New Mexico coworker Magdalena Hurtado, men who killed during raids displayed an even greater advantage in fathering children than the difference that Chagnon observed among Yanomami men. Similar findings emerged in a study of warfare among the Waorani in Ecuador. That work was directed by Carolyn Robarchek and Clayton Robarchek, both of Wichita (Kans.) State University.

The Waorani data, however, don’t fit neatly into Hill’s argument, Clayton Robarchek contends. Small bands of these foragers carried out a century-long cycle of deadly vendettas that thinned their ranks and left their culture on the brink of collapse, he notes. During that time, raiders usually killed women rather than kidnapping or raping them, as the Yanomami did. Men who killed frequently were also most likely to lose wives in warfare, Clayton Robarchek says. Killers’ reproductive success plummeted at times of intensified raiding, when the raiders often died in acts of vengeance.

Waorani violence subsided in the 1950s after missionaries brokered peace talks among villages. That turnaround shows how Western contact can sometimes defuse native violence rather than intensify it, Clayton Robarchek adds. “I don’t agree with Chagnon that men who kill a lot in raids gain cultural success,” he remarks. “But I don’t think Chagnon did anything unethical with his Yanomami data. I suspect he’s being unfairly attacked [in Tierney’s book].”

Noeli Pocaterra, a member of the Venezuelan commission that will investigate Tierney’s charges, sounded less optimistic in a talk at the AAA meeting. Without commenting on Tierney’s specific charges, she said that scientific misconduct by anthropologists often occurs in the field.

“Many of us know that the incidents described in Tierney’s book are not only possible but are real in many native communities,” she says. “We want to clarify each of his allegations.”

Even if the Venezuelan commission succeeds at that daunting task, it seems unlikely that Yanomami-related anthropological hostilities will diminish anytime soon. Meanwhile, an estimated 16,000 to 20,000 Yanomami struggle to preserve their culture against an influx of gold miners and continuing rain forest destruction.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.

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