The Ethics of Non-Human Primate Research

Andrew Fenton and L. Syd M. Johnson criticize the acceptance of non-human primate research.


At the end of 2015, the US National Institutes of Health announced that it would no longer support biomedical research on chimpanzees and that it would send the last of its chimpanzees to sanctuaries. In support of its decision, the National Institutes of Health cited both the reduced need for chimpanzees in biomedical research, and the principles set forth by the Institute of Medicine in its much-needed report on chimpanzee research. This was one of many recent developments that evince ongoing, informed reconsideration of the scientific use of non-human primates. At the same time, some in the biomedical research community have railed against what they consider to be misinformed and extremist propaganda that jeopardizes research on these animals.

In May, 2015 the journal Nature Neuroscience carried an editorial decrying the impact of “animal rights extremists” on the climate surrounding non-human primate research. The impetus for the editorial was the announcement by Nikos Logothetis (a neuroscientist at the Max Planck Institute for Biological Cybernetics), that he was discontinuing his research using rhesus macaques because of “‘never ending abuse’ by animal rights activists.” The editorial called for a significant show of researcher solidarity, greater enforcement of anti-harassment laws, and a push to counter the “distortions” and “terrorism” of animal rights activists with the “truth” about the importance and benefits of harmful non-human primate research in areas like neuroscience.


To be clear, we agree that violence or threats of violence have no place in civil society (though this should not be confused with acts of civil disobedience). It is important, however, to distinguish violence and threats from legitimate dissent. Polarizing language such as “extremist,” “radical,” and “terrorist” found in the Nature Neuroscience editorial, arguably serves not only to silence and discredit dissent, but to deflect the locus of concern from the welfare of non-human primates to the welfare of researchers.

The editorial is rife with distortions of the relevant moral controversies, suggesting that opponents of using non-human primates in neuroscientific research simply (and wrongly) believe the research has no scientific value. But moral objections to research on non-human primates need not deny that useful scientific knowledge can be gained from such research. Indeed, the many biological similarities between human and non-human primates make the latter, in some cases, useful substitutes. But in defending research on non-human primates, the editorial merely assumes the dubious moral stance that the harmful use of some primates is justified because it benefits another set of primates, humans. This stance, though common, is intellectually simplistic and fails to engage the pressing ethical questions.

Imagine that using non-human primates in harmful research is in fact necessary for advancing scientific knowledge. One might still insist that the research ought to be pursued in a way that causes the least harm to the least number of relevant animals needed to achieve the research goals. This reflects a commitment to the 3Rs of animal research ethics: refinement (reducing or eliminating scientifically unnecessary distress, pain, or suffering); reduction (using the minimal number of animals to get the desired scientifically valid results); replacement (whenever possible, using non-animal models or animals less susceptible to distress, pain, or suffering). Currently, this is the dominant ethical framework governing conscientious animal research.

But neither the 3R framework nor the Nature Neuroscience editors asks whether it is ultimately ethical to use non-human animals in harmful research to benefit humans. To expect that of the 3R framework misunderstands its role in animal research. It is, however, rightly expected of conscientious researchers.

To meaningfully and honestly engage the debate about the ethics of using non-human primates in research, the editors of Nature Neuroscience, and researchers like Nikos Logothetis should keep two things in mind: (i) the moral arbitrariness of appealing to species membership alone to settle the question; (ii) the diversity of capacities expressed among the population of humans protected from the kind of research routinely carried out on other animals.

To move the debate forward, those who would defend the use of non-human primates in research should explain what capacities and characteristics (or lack thereof) would permit their use in research, when doing the very same research with humans would be unconscionable. And, from our perspective, the explanation can’t simply be “species identity.” An appeal to species identity only makes sense if it reliably picks out capacities of moral significance that, in this context, all non-human primates lack, and that all humans possess. But no such capacities exist, and without such a justification, the scientific usefulness of the relevant research is really beside the point.

Nature Neuroscience would have us believe that simply getting straight on the human benefits of research can then set us, “the public,” straight regarding the legitimacy of using other animals to increase human knowledge or benefit biomedicine. They overestimate the ignorance of the relevant publics, and underestimate both their sophistication and their concerns about animal welfare. Attitudes among various publics are changing, and increasing discomfort with research on non-human primates arises not from ignorance of the benefits of science but because of what the cognitive and behavioral sciences have already revealed about the psychological complexity and capacities of non-human primates.


Andrew Fenton is an Assistant Professor in the Department of Philosophy, California State University – Fresno

L. Syd M. Johnson is Assistant Professor of Philosophy & Bioethics in the Department of Humanities at Michigan Technological University, Michigan USA @LSydMJohnson