Raised in total or partial social isolation, clinging desperately to wire or cloth “mothers,” rhesus monkey infants subjected to American psychologist Harry F. Harlow's maternal-deprivation experiments in the 1950s self-mutilated, rocked, and showed other signs of deep depression and anxiety. Based on the principle that animal models could illuminate issues of maternal care and depression in humans, Harlow's research is still discussed in psychology, anthropology and animal behavior classes. Yet this kind of profound primate suffering is not consigned to the historical record. Today rhesus monkey infants are still forcibly separated by laboratory researchers from their mothers and stressed in ways that leave them physically and emotionally traumatized.
At the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Laboratory of Comparative Ethology (LCE) in Poolesville, Md., headed by psychologist Stephen Suomi, infant monkeys are taken from their mothers often within hours of birth. For 22 hours a day (24 on weekends), these infants have no cage mates with which to interact. As I know from my work with free-ranging infant wild baboons in Kenya—monkeys that have a social organization similar to that of the rhesus—this regimen results in a terrible distortion of the animals' natural way of life. In the wild, these monkey infants live at the secure center of a matriline, a group of related females. They play with peers and explore their world but scamper back to the warmth and protection of the most important being in their lives, the mother.
At the LCE, in contrast, the motherless infants undergo stressors (such as being intentionally frightened while they are alone) in experiments designed to evaluate their reactivity and thus to understand developmental risk factors leading to mental illness in humans. Peer-reviewed literature from the LCE reports that these infants suffer behavioral and biological consequences for the duration of their lives, including poor health, increased stress, maternal incompetence and abnormal aggression.
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As a person who watches two beloved family members struggle with mental illness, I know the importance of research in this arena. Yet systematic reviews tell us conclusively that animal models do not translate well to human mental health. To treat mental illness in humans requires direct attention to the real stressors we experience in our own lives—not artificial ones that we make rhesus infants endure. Research of diverse types, including neuroimaging and long-term follow-up of patients' day-to-day lives, is making substantive inroads in this endeavor.
It is no adequate defense to note that this kind of research meets federal and university animal care guidelines. The bar to gain approval to experiment invasively on primates (and other animals) is quite low. As Lawrence Arthur Hansen pointed out two years ago in the Journal of Medical Ethics, oversight committees are disproportionately composed of the very people who derive their livelihood from continuing these experiments: animal researchers and institutional veterinarians.
Bringing onboard knowledgeable parties who do not directly benefit from money awarded to these projects—social scientists and bioethicists, for instance—would be a first step in addressing this skew. As Hansen observes, though, equally necessary is a change in institutional culture to ensure that committees more directly consider benefit-harm issues.
I am struck by parallels with the case of biomedical research on chimpanzees at the National Institutes of Health, which in 2011 was deemed “unnecessary” by an independent Institute of Medicine review. Repeatedly, biomedical studies on chimpanzees had been approved by review boards and animal care committees. The oversight process did not ethically protect those lab chimpanzees in the past, and it is not ethically protecting the lab monkeys now.
It is not necessary to be against all biomedical research on nonhuman primates to see how outdated and misguided some research is. It is time to end Harlow's cruel legacy.