Light drifts in from near the 37-foot-high ceilings despite the "protective" shutters on the window's outside—almost like rays of sun seeping through the rainforest canopy? (Courtesy of Brian Ludwig)

Light drifts in from near the 37-foot-high ceilings despite the “protective” shutters on the window’s outside—almost like rays of sun seeping through the rainforest canopy? (Courtesy of Brian Ludwig)

According to a March 30, 2012 inventory, there were six labs at Princeton University that held nonhuman animals for experimentation. Between them, they contained over 10,000 mice, nearly 2,000 fish, nearly 1,000 larval salamanders, and a smattering of rats and frogs. However, it is the two least populous species that have been subject to the most attention: 11 macaques and 16 marmosets—27 monkeys kept in on-campus cages.

The exact numbers fluctuate, depending on the researchers’ needs. Princeton had 71 nonhuman primates in 2005, but by 2008, all but 18 of these had been retired to a sanctuary in Texas. Since then, the number has crept back upwards: a 2013 USDA report counted 47 nonhuman primates.

Earlier USDA inspections had found several violations, and a group of community members using the website held demonstrations and passed out flyers in the fall of 2011. This was all reported in the Daily Princetonian, but I don’t remember any discussion about it on campus. At the time I was still weighing whether I could ethically continue to eat meat, and I don’t think I had the moral energy to engage with animal testing. Apparently community members regularly protested through 2013, but you could have fooled me. In fact, I had forgotten Princeton even had monkeys until last spring, when a friend in the neuroscience program reminded me.

Neuro Professor Asif Ghazanfar’s lab aims to “understand the evolutionary and developmental bases for communication in humans,” and is one of the few labs at Princeton to currently use “primate model systems,” which is what they choose to call living, breathing, monkeys. Nonhuman primates are ideal for this research because their “communication behaviors…are similar to ours. This approach allows us to determine the evolutionary origins of these behaviors, but more importantly it gives us insights into what may go awry in disorders of human communication.”

There is no question that the lab’s results are intriguing, and relevant to the evolution of communication. The lab has at least convinced its funders—including the National Institute for Neurological Disorders & Stroke, the James S. McDonnell Foundation (whose mission is to “improve the quality of life,” presumably of humans), and Autism Speaks—that these insights into human disorders are worthwhile (though they are several steps removed from concrete effect). But this knowledge has a price: a few dozen of our not-so-distant cousins are held captive for years and, as I soon discovered, routinely subjected to highly distressing conditions.

It may seem strange to focus on monkeys—or at least, University spokesperson Martin Mbugua seemed to think so. Monkeys represent only a tiny fraction of the animals on campus, so to make them “the focus of an article,” as he informed me when I reached out for comment, “would certainly be misleading and sensational.” He may be right that the rodent majority deserves more attention: mice and rats, along with all non-mammals, are bizarrely excluded from the Animal Welfare Act (AWA), and their treatment is less regulated. (This lack of regulation is part of the reason why they so outnumber monkeys; the main reason, however, is that obtaining and caring for primates is expensive.) Princeton’s primates, on the other hand, are treated better than the law requires, often caged in pairs or groups instead of isolation, and provided with mental stimulation through toys and cartoons. While mice and rats are generally euthanized at the end of each experiment—some are literally sent to a guillotine—most (though not all) of Princeton’s monkeys get to live out their post-research days in a sanctuary with their peers.

But monkeys are closer to us in cognition and social behavior than many other animals, and while I don’t at all want to diminish the moral relevance of mistreating mice and fish, there is arguably a case to prioritize our fellow primates. One article would never be enough to assess the state of all animal research at Princeton, so I have chosen to investigate the lab that has faced the most public debate. With apologies to Martin Mbugua, let us explore the sensational lives of Princeton’s marmosets and macaques.

The common marmoset is less than eight inches tall, and lives in the forests of Brazil. Per the Animal Welfare Act (AWA), it is perfectly legal to keep them in cages with floor area as small as 1.6 square feet—less than three sheets of paper—and only 20 inches high. Princeton, to its credit, exceeds this standard, and inserts perches, tree branches, and other environmental stimulants. However, one wonders if even the most well-designed indoor marmoset environment might get stale over the course of years.

Princeton neuroscientists also experiment on rhesus and cynomolgus (or “crab-eating,” or “long-tailed”) macaques, both species native to Southeast Asia. These roughly 20-inch tall creatures get a more spacious allotment for their cages from the AWA: 30 inches high with a 4.3-square-foot base (though again, Princeton exceeds the standard). Unlike Princeton’s marmosets, which are a breeding colony of males and females of all ages, our macaque population is all male. As Princeton’s “Institutional Policies Governing Animal Research” puts it, “Although social interaction is an important factor influencing the psychological well-being of nonhuman primates, oftentimes it is impossible to establish conspecific pairs due to injurious aggression toward one another.” In other words, when you put a handful of single males together from a species that usually lives in large, predominantly female groups, they don’t get along. Two undergraduate neuroscience students have separately told me that they heard the macaques were foul-tempered. Now we know one reason why.

But given adequate social conditions, macaques have a soft side. Primatologist Frans de Waal once observed a rhesus monkey named Azalea with a simian analogue to Down syndrome: she performed “incomprehensible blunders” such as challenging the alpha male, but the normally hierarchical creatures simply brushed her missteps aside, showing much greater tolerance than they typically would. He attributes their permissive behavior to a form of empathy; they somehow understood that Azalea should not be held to the same standards.

It must be said that we cannot accurately ascribe motivation to a monkey. An action that may look to us to be kind or empathetic does not necessarily mean the monkey is experiencing anything like the corresponding human emotions. But it seems at least as foolish to assume that our close evolutionary relatives can’t have similar feelings. As we continue to learn more about monkey behavior, it becomes harder to justify their continued exploitation.

I began to examine Ghazanfar’s research and found some of it fascinating. A result picked up in several science news outlets in fall 2013 showed that marmosets take turns speaking, even when they can’t see each other. This behavior may have evolved to enhance cooperation. Both marmoset parents take care of their offspring, as is common in humans but few other primates, and marmosets are among the friendlier monkeys. Macaques, for their part, were shown by Ghazanfar’s team in 2011 to use facial cues to better understand each other’s vocal signals. Like humans, they communicate most effectively when they can both see and hear each other.

PETA is harder to impress, and has been keeping tabs on Princeton’s animal labs. They sent me several papers written by Princeton scientists that, according to the animal rights nonprofit, used particularly egregious methods. However, reading the published papers is rather confusing if you don’t know how these methods work. Most people don’t know what a “primate chair” or a “restraint chair” looks like, or what it means to surgically implant a “head-post.” If anything, training via “standard operant conditioning techniques” using a “juice reward” sounds like it could be kind of a fun game for the macaques—who doesn’t like juice?

Monkeys have gone through a lot in the world’s research labs: in her book Experimenting with Humans and Animals, historian Anita Guerrini lists “radiation exposure, space flight, blunt impact trauma, vertigo, gunshot wounds, and a number of diseases,” as a sampling of past abuse. In comparison, “restraint chair” seems quite mild—and in a relative sense, it is. But “better than radiation exposure” does not tell us much.

For more information, I turned to Ghazanfar’s 2006 application for funding from the National Institute of Health (NIH), for which his lab received, spread out over five years, a sum of $1,679,761. The final pages cover the procedure for the 10 long-tailed macaques that would be used. Together with the “Institutional Policies Governing Animal Research”—which, by the way, are barred to everyone without a NetID—we begin to arrive at a picture of these monkeys’ lives.

“To prevent regurgitation during anesthesia,” the macaques are forced to fast for 12 hours before the surgery (generally done overnight). A “headbolt” is then attached to their skull, which will secure their head in position while they are in the restraint chair. They are then kept “in a warm, padded recovery cage,” given opioids for at least the first twenty-four hours, and for longer “if the animal exhibits any signs of pain or distress, i.e. guarding, vocalizing, self-mutilation, restlessness, recumbency, abnormal posturing, rapid respiration rate, or significant decrease in activity.”

Then it is time for the training. Each macaque’s average daily water intake is measured, and then his water source is removed. Instead, when the macaque performs the desired task in the restraint chair, he is given juice. Outside of the chair, the macaque is given a limited supply of bottled water, only enough to make up the difference between his juice intake and his predetermined daily average. The reason for this is not stated, but presumably this is to insure that the juice reward is an effective motivator. Upon any indication of dehydration—“listlessness, decreased activity, depression, decreased weight of >= 10% and anorexia—e.g., failure to eat biscuits”—the animal is “immediately given controlled access to water and is temporarily removed from the experimental protocol.”

The restraint chair used by Princeton (sometimes called a “primate chair” to be more specific and euphemistic) is not described in detail, and there are a number of different varieties. “Chair” is probably the wrong word; they are complex contraptions designed to minimize the primate’s movement, constraining the lower body and securing the individual at the neck, usually the arms, and sometimes the legs. One hopes that Princeton uses one of the less draconian designs, because after all, these macaques already have their heads screwed into a metal bar.

The experiment itself takes place for five hours each day, five days a week. Five hours a day with his head attached to a post, unable to move. A Princeton policy on physical restraint states that researchers must give the primates a one-hour, unrestrained food and water break only when the period of restraint exceeds 12 hours—and even then, not if “continuous restraint is required by the research proposal.” A separate document on the “Psychological Well-Being of Nonhuman Primates” only says that when the procedure is approved, “macaques may undergo short (<4 hours) periods of restraint,” with no mention of whether longer restraints are an option.

Regardless of which of these assorted documents takes precedence, if we are asking whether four, five, or twelve hours is the proper amount of time for a monkey to be immobilized via “head-post” before you give him a food and water break, I think we’ve lost sight of the real question. We may have found another reason for the macaques’ alleged foul tempers. [Addendum 8/16/15: While the grant proposal suggests restraint sessions would be 5 hours, 5 days/week, Ghazanfar’s published research suggests the monkeys were generally restrained for significantly shorter lengths of time.]

For these unlucky ten macaques, Ghazanfar’s grant application makes no mention of a sunny retirement. The only fate proposed was “an overdose of sodium pentobarbital.”

Not all of Princeton’s monkeys are subjected to such invasive procedures—there is a gradient. However, all of them are subject to captivity. They were recently moved to Peretsman-Scully Hall, along with many of our other animals—the nonhuman primates occupy level two of the new neuroscience building.

Their new living conditions are detailed in an August 2014 article at, a website that supplies institutions with general information regarding “facility assets.”[Update 8/1/15: This article is no longer accessible. The Nass reached out to Tradeline for comment, and a representative replied, “Unfortunately, we don’t provide details as to why” articles “are unpublished from our website.”] The cages are stacked in sets of two, and the monkeys are given access to an “enrichment room.” This has 37-foot high ceilings, perches and ropes for sitting and climbing, and may even accommodate “a wading pool or a small-scale play set.” According to Laboratory Animal Resources director and attending veterinarian Laura Conour, the monkeys are already reacting positively to the natural light that seeps in from windows near the top of the room. In designing the enclosure, Conour took pride in bringing a “European-Union-style flair,” a reference to the unique inadequacy of US regulations.

The University explicitly acknowledges the boredom that must accompany hours in a restraint chair, or in a cage—hence the need for “enrichment,” and the document on monkeys’ “psychological well-being.” They achieve this not only through toys and natural lighting, but through cartoons and—in a somewhat dystopian twist—nature documentaries, and recorded audio of forest sounds. While watching Planet Earth was certainly enriching for me personally, I find a tragic irony in the idea of a creature who lives out each day in an indoor cage finding comfort in images of the outdoors.

Even those who don’t object to testing rarely claim a subject’s life is paradise. Activists are told to think of the noble pursuit of scientific progress, and the good that comes out of experiments. As Martin Mbugua of Princeton’s Office of Communications wrote to me, “animal research at institutions like Princeton leads to breakthroughs that benefit not only people, but also the environment, and even other animal species.” When it comes to animal testing, suddenly everyone’s a utilitarian.

I reached out to Ghazanfar, Conour, and a few other members of Princeton’s animal labs to ask their thoughts on their work for this article. Those who responded seemed interested in my project, but told me that questions about animal testing must first go through the Office of Communications. Martin Mbugua gave me a surface level response and did not answer most of my questions, “for safety and other reasons.” He not only denied me contact with the people best suited to defend primate testing—the ones working in the lab—but also discouraged me from speaking with animal rights activists: “Engaging in a discussion in that direction would not be helpful.” Apparently the University is more accommodating of “” than student journalism, and discourages any critical student discussion of University policies.

So to defend animal testing, I am left with five links from the Ghazanfar lab’s website, one of which does not work. A couple of the sites address animal ethics: the consensus seems to be that of course animal pain matters morally, but that nonhumans can’t have “rights,” because they don’t have sufficient intelligence to develop complex moralities or to respect the rights of others. Therefore, we can cause them distress and kill them if we have a good enough reason, and medical progress is seen as exactly that. While the language of utilitarianism is often used to highlight the benefits of animal testing, the functional difference between humans and other animals is that only we have rights.

Whether or not you buy this argument, I ask you once again to picture the macaque with a surgically implanted bolt in his skull, immobilized by a post into his head for hours at a time. [Addendum 8/16/2015: At least according to the grant proposal.] Must we accept this as the best way to address human communication disorders?

Princeton’s own Peter Singer, most certainly a utilitarian, helped launch the modern philosophical discussion of animal ethics with his 1975 book Animal Liberation. He asks us to weigh the interests of all sentient beings equally; to do otherwise is “speciesist.”

Equal consideration does not necessarily mean equal treatment—monkeys and humans require different conditions to live pleasant lives. However, they experience pain in similar ways. The basic structures of all other vertebrate nervous systems aren’t wildly different from our own, and this is especially true within the primate family. As such, both species have interests in avoiding pain and distress, and these interests are equally valuable.

In Animal Liberation, Singer documents a string of painful experiments, many involving electric shocks or inflicted diseases, and many of which seem to have only trivial scientific benefit. It is clear to him that most animal experimentation is unjustified, but he does not call for its abolition. In 2006, Singer addressed an experiment in which about 100 monkeys were induced with Parkinson’s; the treatment that was developed has benefited 40,000 humans. He says he “could see this as justifiable research.”

Lori Gruen, Professor of Philosophy, Environmental Studies, and Feminist, Gender, and Sexuality Studies at Wesleyan University, is less convinced that any such research can be justified. She calls Singer’s criterion the “Non-speciesist Utility Test,” and uses his own premises to challenge his conclusion. First, she argues that the harm is much greater than Singer accounts for. In the case of the Parkinson’s experiment, Gruen might say that counting only the last 100 monkeys ignores the untold numbers of animals sacrificed for basic brain research, the numerous failed Parkinson’s tests that preceded the successful one, and every other experiment directly or indirectly related to Parkinson’s.

Second, she would say that because the bulk of invasive Parkinson’s research falls upon nonhuman animals, the whole system is guilty of speciesism. Animal testing treats nonhumans as means for human ends, and inherently violates Singer’s principle of equal consideration of interests. So his approach should lead to, if not full abolition, something pretty close.

I, along with most animal liberation philosophers, readily admit that to do some of these things to a human is worse than to do it to a marmoset. But if you look at the reasons why it’s bad to experiment on a human, many also apply to at least some nonhumans. Both feel pain, both can be bored, or afraid, or otherwise distressed. Both would be happier in a different situation, and in some cases both are able to plan for the future. Humans value agency over their own lives in a way that most other animals may or may not, and the effect of experimenting on us would have broad repercussions throughout our entire society. Still, there is overlap in the way that humans and animals can be harmed.

And humans, quite often, are harmed. In Nazi Germany, doctors performed horrific experiments upon patients in the concentration camps. In mid-20th century America, researchers observed a group of black men with syphilis, which became treatable partway through the experiment, so that they could watch the disease progress.

But it is perhaps the incarcerated, those labeled criminals, who have seen the worst of it—and this violence is historically intertwined with the violence of animal testing. The same ancient Roman physicians who dissected living animals would dissect living humans, selected from prison for the benefit of science. Testing smallpox inoculations on human prisoners in the 1700s paved the way for vaccine research on animals. Two centuries later, Jonas Salk would usher in the modern era of widespread primate experimentation by using at least a million of them in his quest for a polio vaccine.  When he started to find success, he asked to try his vaccine on prisoners. He was denied, but was later allowed to test it on mentally ill children.


Before the move-in: three stacks of two cages adjacent to the “enrichment room.”

Most recently, The Nation reported that the two psychologists hired by the CIA to oversee the torture of detainees throughout the War on Terror were motivated in part by “a curiosity about whether theories of ‘learned helplessness’ derived from experiments on dogs might work on human enemies.”

Our sordid past and present suggest that we choose to imprison and abuse primarily those who are most vulnerable. We are motivated by dominance, and the different forms this dominance takes mutually bolster one another. The history of experimenting on animals, human and nonhuman alike, shows our refusal to acknowledge what we all have in common.

I have spoken off the record to a few undergraduates about their work with mice, and more than one have said they feel awful about the killing. The University knows this, and the official policy on euthanasia recognizes that the process “may be disturbing to some.” But undergraduates are told that torture and death are necessary for science, and the grad students and professors they work with appear numbed to the process by long years in the lab, so they do not talk about it.

This numbness is not an accident: perhaps the most disturbing sentence on the policy sheet reads, “Those who perform euthanasia on a routine bases [sic] may experience compassion fatigue.” Another document refers to “nonsurvival surgeries,” a subclass of euthanasia. The aggressively euphemistic language is intentional, and historically was meant to avoid backlash from animal advocates. However, this language has also served to detach the scientists from their mechanized “animal models.” I do not doubt that most of the scientists are warm and loving in much of their lives, and that many even like the monkeys. But their careers depend on not questioning their experiments; they are told that “compassion fatigue” is an acceptable side effect.

In 2011, we learned the practical effects of this detachment, in the form of a series of USDA violations. Some were technicalities—incomplete descriptions of protocol, or failure to provide the right documentation. Others were more troubling.

On one occasion in March 2011, lab personnel were told to inform a veterinarian that a marmoset was about to give birth; they did not. The vet was also not informed in December 2009, when a monkey who had recently undergone surgery exhibited signs of pain and distress. This negligence reaches new heights in the USDA reports’ most pervasive violation: “a possible pattern of depriving non human primates of water for a period of greater than 24 hours,” causing, as they put it, “increased distress.”

Princeton’s primate lab managed to avoid reported violations from 2011 until June 2014, when an email leaked to PETA revealed a bizarre bit of alleged marmoset abuse. According to the email, written by Ghazanfar, “one or more (I didn’t get the details) was/ were placed in a ferret exercise ball solely for the entertainment of some of our lab members. This could only have been stressful for the marmosets.” Ghazanfar, to his credit, then forcefully implored his colleagues to treat the marmosets respectfully.

When I heard about this incident, a friend from PETA asked me to take action. With help from others, I wrote a petition calling for, among other things, greater transparency: this incident would have remained hidden without a whistleblower, most of our policies are unavailable to the public, and my own experience trying to write this article showed how hard it was even to discuss this topic. We also asked for the affected marmoset(s) to be retired to a sanctuary. PETA publicized its own petition, calling for the entire marmoset colony to be relocated. I got some signatures, PETA got thousands, Peter Singer tweeted about it, and another student and I eventually met with three research administrators: Conour, Pablo Debenedetti (the Dean of Research), and Stuart Leland (the Director of Research Integrity and Assurance).

The meeting was off the record, but I felt my grievances were well-received, even if we did not agree on all solutions. They told me they would look into one of my proposed reforms: adding a student seat to Princeton’s Institutional Animal Care and Use Committee (IACUC). IACUC must approve every animal experiment, and is tasked to assure compliance with federal standards. A subcommittee of IACUC also conducted an internal investigation into the marmoset incident, and found that there had been a misunderstanding. The marmosets had actually been placed in the ferret exercise balls to prepare them for a future experiment; it was not for entertainment, and it did not cause distress. This is still a violation—such an act would have required IACUC approval— but a less offensive one.

IACUCs are intended to be a mix of scientists, ethicists, religious leaders, and other community members. However, according to a March 30, 2012 document I obtained through the Freedom of Information Act, six of the ten voting members of the majority-rule committee are “practicing scientist[s] experienced in research involving animals”—four professors, a lab manager, and the assistant director of Laboratory Animal Resources.

Only one is labeled a “Nonscientist,” meaning their “primary concerns are in a nonscientific area (e.g., ethicist, lawyer, member of the clergy),” and two are “Non-affiliated,” and “expected to represent general community interests.” Conour herself is the tenth member. Again, I do not doubt that these scientists are committed to minimizing animal distress within the confines of their experiments, but I feel that more outside perspectives with less vested interest in Princeton’s animal program can only help.

I decided to put off this article until a decision had been reached about the student IACUC seat— and after several months, I finally met with Dean Debenedetti again on February 13. After discussing amongst themselves and researching the policies of peer institutions, IACUC had voted to create a slot each semester for a grad student to join as a full voting member. (An undergrad post was considered, but they deemed the workload too demanding.) The next time IACUC is discussing whether lab conditions are up to standards, I will be glad for a younger pair of eyes.

Debenedetti also told me that Leland is looking into different forms of outreach with the undergraduate community, to add some measure of transparency between Princeton’s animal labs and the student body. While neither of these reforms is radical, any steps toward greater openness are encouraging. I am sincerely grateful that Debenedetti, Leland, Conour, and IACUC took me seriously, and hope that they continue to have productive relationships with undergrads.

However, the major ask of both my petition and PETA’s, that some or all of the marmosets be moved to a sanctuary, was never really considered. The cage may overflow with toys and cartoons, but no one can challenge the existence of the cage itself. Meanwhile more taxpayer money funnels to Princeton, which passes it on to the lucrative peddlers of living and nonliving research tools, and a few humans profit while their monkeys are deprived of water and bolted to posts.

We justify this to ourselves by clinging to the success of the polio vaccine, and then we probe our primates for some nebulous evolutionary link to “disorders of human communication.” A quiet voice asks if these disorders are so awful that they call for any means necessary in animal labs across the globe—but no, we cannot let ourselves consider that. Put a wading pool in the enrichment room, but never question the logic of exploitation, of humankind’s unassailable supremacy and the monkey’s inherent inferiority. I can petition all I want to add another toy, a new position on IACUC; but what if I want to dismantle the cage?

There are monkeys right up the stairs. They live on level two of the Princeton Neuroscience Institute, atop several stories of mice, rats, and fish. I once had to run a brief errand in Peretsman-Scully Hall: there is nothing to suggest that the nice, warm building is a prison, and I am sure it was designed in part to hide that reality—even from the prison guards themselves.

When Superstorm Sandy struck Princeton in fall of 2012, only two types of facilities kept electricity: student dorms and animal labs. The nonhumans, like us, are an investment that Princeton has made. Despite the negligence that appears endemic to the labs, it ultimately makes financial sense to keep the creatures alive, at least as long as grant money keeps flowing in. But this also means the University is financially committed to keeping its primates—human student activists and nonhuman victims— in their place. We don’t have to let them.

Correction: an earlier version of this article incorrectly stated that Ghazanfar’s lab was the only Princeton lab to use nonhuman primates. The Nass regrets the error.