Protecting isolated tribes

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Science  05 Jun 2015:
Vol. 348, Issue 6239, pp. 1061
DOI: 10.1126/science.aac6540

There are about 50 isolated indigenous societies across lowland South America, with limited to no contact with the outside world. Despite displacements, epidemics, and hostile interactions with outsiders, such tribes still manage to survive. How can we ensure the well-being of humanity's last known isolated peoples under such enormous and mounting pressure from external threats?

Generally, the current policy of governments, primarily those of Brazil and Peru, and supported by the United Nations, is a “leave them alone” strategy. There are two implicit assumptions in a no-contact approach, however: that isolated populations are viable in the long term, and that they would choose isolation if they had full information (i.e., if they were aware that contact would not lead to massacre and enslavement). The first assumption is unlikely. Ethnohistorical accounts reveal the real risk of severe depopulation or extinction during intermittent hostile and sporadic interaction with the outside world. Miners, loggers, and hunters penetrate into the homelands of isolated tribes despite government “protection.” Unless protection efforts against external threats and accidental encounters are drastically increased, the chances that these tribes will survive are slim. Disease epidemics, compounded by demographic variability and inbreeding effects, makes the disappearance of small, isolated groups very probable in the near future. The second assumption is also unlikely. Interviews indicate that contacted groups had mainly chosen isolation out of fear of being killed or enslaved, but they also wanted outside goods and innovations and positive social interactions with neighbors.

“Controlled contact with isolated peoples is a better option than a no-contact policy.”


Controlled contact with isolated peoples is a better option than a no-contact policy. This means that governments should initiate contact only after conceiving a well-organized plan. In the past, there have been many poorly planned contacts with isolated Amazonian tribes by both missionaries and government agencies. The absence of health care professionals and health monitoring led to many deaths of these vulnerable peoples. One of us (K.R.H.) was on site within weeks of the first peaceful contacts with Aché, Yora, Mascho-Piro, and Matsiguenga communities in Paraguay and Peru when they were extremely isolated and suffering from new contact-related epidemics (from the late 1970s to mid-1980s), even though intermittent contact (mostly accidental) had occurred for 25 years. The most important lesson learned from these experiences is that mortality can be reduced to near zero if the contact team is prepared to provide sustained, around-the-clock medical treatment, as well as food. A well-designed contact can be quite safe, compared to the disastrous outcomes from accidental contacts. But safe contact requires a qualified team of cultural translators and health care professionals that is committed to staying on site for more than a year. For example, foreign missionaries provided great care for the Yora for up to 6 months, but when they decided to take a furlough, dozens of Yora died within a few weeks. Similarly, in 1975, missionaries provided care to an Aché community for a year, but when they took a vacation, many Aché died. Fortunately, there have been some success stories such as a 1978 contact with a band of Northern Aché. Missionaries and anthropologists treated them with antibiotics when primary respiratory infections progressed to pneumonia. They also provided food to the sick.

Given that isolated populations are not viable in the long term, well-organized contacts are today both humane and ethical. We know that soon after peaceful contact with the outside world, surviving indigenous populations rebound quickly from population crashes, ,with growth rates over 3% per year. Once a sustained peaceful contact occurs, it becomes much easier to protect native rights than it otherwise would be for isolated populations. Leaving groups isolated, yet still exposed to dangerous and uncontrolled interactions with the outside world, is a violation of governmental responsibility. By refusing authorized, well-planned contacts, governments are simply guaranteeing that accidental and disastrous contacts will take place instead.

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