An experience in informed consent

  • Kenneth Weiss

Half a century ago, a number of expeditions were taken by US, South American, and European scientists into the hinterlands of the Amazon rainforest. Most or all of the tribal groups they visited were near Catholic mission stations, where there was a lot of interaction, or people were interacting in other ways with the colonizers of the continent.

Napoleon Chagnon, then at the University of Michigan (and whom I knew as a graduate student and post-doc), with contributions from other investigators, made the Yanomami tribal group of the Amazon basin the most famous 'native' population in the world. For many years Nap was the world's most prominent cultural anthropologist, probably succeeding Margaret Mead in that distinction. Indeed, he may still be. His work was assertive, among other things driven by evolutionary theory about reproductive dominance and behavior in tribal human societies, and the aggression that went with that. He was a pro-active rather than purely observational anthropologist. This naturally raised opposition and contention, of which there has been an ample amount for decades.

As well as cultural studies there were biomedical and in particular genetic studies of the many Yanomami villages. The object was to test some ideas about the amount of mutation that arose and the persistence of genetic variation in tribal groups living under their kinds of conditions. Could the Yanomami social and reproductive structure, in particular group size, fragmentation, and dominance hierarchies, tell us anything about the way genetic variation had been maintained in our ancestral populations? The interest was not purely scientific, but more specifically was about the dangers we in the developed world faced as a consequence of our exposure to mutagens. In particular, at the time, was concern over exposure to nuclear radiation from x-rays and the like, and fallout from nuclear bomb testing.

Jim Neel a world-leading geneticist at the University of Michigan was the primary biomedical/genetic investigator. He was working on the health effects on survivors of the atomic bombs that had been dropped on Nagasaki and Hiroshima during World War II, and had a keen interest in these questions. He was also my post-doc supervisor, and when years later he retired, he asked me and a couple of other investigators to be custodian of the DNA samples, and to analyze them as new technologies made that possible. But in 2000, a book called Darkness in El Dorado by Patrick Tierney was published. Tierney accused Neel and Chagnon (and others) of grievous abuses of the Yanomami, taking harmful advantage of the tribe for their own professional advancement. We've previously written about these issues here, and beginning here.

Major controversies have swirled around these accusations, and there is no need to go into them here. An available HBO film, Secrets of the Tribe, and several YouTube videos and published articles and stories can be easily found if you want to learn more. The point is that after Darkness appeared, Yanomami and various advocates and spokespersons demanded the return of the blood samples, which had become symbolic of the outside interference so resented by the tribe. This request for return has led to over ten years of interactions between us and the Brazilian government to find a way to ship the samples collected there back to them, safely, and free of legal entanglements about the samples and the work done in the tribal area. This was not contentious negotiation, just a matter of the complex logistics (including biosafety, getting samples to Amazonia) and technical (liability issues) things to work out.

Well, finally, yesterday, the samples were shipped back to Brazil. I hope they arrive on location without incident, and that the Yanomami are pleased. We are relieved that at least this aspect of contention has passed. It won't change any feelings of having been taken advantage of, perhaps, but it may help show at least respect and good intentions.

What is informed consent?
These samples were collected in complete compliance with the informed consent conditions of fifty years ago. But since various untoward things have happened to the Yanomami, what was at the time clearly a voluntary cooperation with the outside scientists (based on extensive filming), has been seen in retrospect as exploitive in various ways that include stimulating violence and even child sexual abuse. Exploitation by unrelated outsiders, such as mineral prospectors, has apparently caused much harm, and the Indians, searching for whatever redress they can obtain, see the continuing presence of the blood samples at various US institutions as symbolic of their sufferings. I was not involved in the collection of these bloods, and have never been to the Yanomami territory. So I cannot comment about those grievances.

However, I was blamed for having the samples in my possession as caretaker and someone who could do further analysis of their genetics, as if guilty of the decades-earlier abuses simply by association with the blood samples. My only work at the time had been to analyze the Yanomami demographic data (after they were collected, when I was a post-doc) jointly with Jim Neel. But as caretaker of the samples I have been accused of nefarious acts, none of which I had committed. I'm glad those samples have been returned, in part because I hope it makes clear my good intentions, but also because, once requested, we had no right to retain them.

This contentious affair raises many questions about informed consent. Above all, I think, is that informed consent never ends. Subjects have, and should have, the right to withdraw from a study at any time and for any expressed reason. Indeed, we have no right to ask for a reason. Being ticked off at the outside world is as good as just saying "Remove me from your study, please."

One must recognize that when data about a sample have been published or melded into a large data base, or distributed anonymously and analyzed by various groups, turned into a patented product, or in other ways already analyzed, that such results cannot be un-published. This is probably particularly relevant to genetic studies because of their complex statistical analytic nature. But beyond that, rights should belong to the study subject, unless quid pro quo's and the like have been arranged at the time of collection, when conditions of participation and so on should be clearly settled at the time. Investigators often try by various subtleties to retain rights, or obtain consent, that one knows, realistically, are not understood adequately by the study subjects. Once DNA is in our hands, the temptation to study whatever becomes possible to study is hard to resist. After all, study subjects are not as a rule technically aware and/or the investigators have clear self-interest.

Anyone who thinks informed consent is usually truly 'informed' is kidding him or herself. Even the investigators cannot know the benefits or risks that may be involved, because if they did the science would not be necessary. Subjects may be ill or even desperate patients seeking treatment, or subjects may be offered compensation for their participation. This doesn't mean there is any evil intent on either party's behalf. Vague promises of follow-up of various kinds are often made, sincerely or naively, but are often not kept or are conveniently interpreted by both parties.

We know a lot more about informed consent now than in the 1960s, but still issues arise because both subject and investigator have clear self-interests but also because the science has become ever more complex. Decisions about restrictions and restraints seem, to me personally, too often to rest with the investigators, and the power is largely in their hands. Rationales for doing things in, say, other countries that can't be done here seem rather common. These have been difficult issues for many decades, especially after the eugenic era abuses. The issues are likely to remain challenging. There are no clear answers, but at least we think that withdrawal without needing to give a reason should always be allowed, unless the work has been done and makes it impossible, as noted earlier.

But at least some contentious samples have been returned.


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