Perspectives On Medical Research

Volume 5, 1995

Aping Science

A Critical Analysis of Research at the Yerkes
Regional Primate Research Center

Review of Yerkes Primate Experiments

In all but name, the Yerkes Regional Primate Research Center existed decades before it attained Congressional funding. Psychologist Robert Yerkes had established the Yale Laboratories for Primate Biology at Orange Grove, Florida in 1918 with a specific focus on the behavior of great apes, particularly the sexual behavior of chimpanzees, orangutans, and gorillas.¹ While Yerkes argued that great ape research would help combat a wide range of human illnesses, sociologist Donna Haraway has argued that his primary interest was in social engineering.² According to her analysis, Yerkes hoped that understanding great ape behavior would enable social scientists to modify citizen behavior and thereby create a smoothly functioning society.

In the 1940s, Yerkes’ research focus shifted from behavioral studies to infectious diseases, and several Yerkes chimpanzees were sent to Albert Sabin to test his oral polio vaccine.³ Since infectious diseases tend to have acute onsets and short durations, captured wild primates were generally used. Studies of chronic diseases, however, required the stable primate population offered by a primate colony. A significant impetus for funding such a primate center was generated by the Cold War mentality that featured intense American-Soviet competition. American scientists visiting Soviet research facilities found that Soviet science surpassed American research in primate investigation. The American delegation was particularly impressed that Soviet researchers had induced hypertension and coronary artery occlusion in rhesus monkeys placed under psychological stress. However, the Americans found that these “experiments have been performed on only a few animals, and there has been difficulty in repeating them.”⁴

With growing interest in vascular disease, James Watt, Director of the National Heart Institute (NHI), called for federal funding of primate centers. However, in testifying before Congress, he submitted an NHI report that did not detail specific scientific justification for such centers. Instead, it provided only vague research “objectives”:

(1) The investigation of normal cardiovascular structure and function, and of cardiovascular disorders of primates, naturally occurring or experimentally induced;

(2) Studies related to these;

(3) Providing scientific information on primates that might lead to a better understanding of cardiovascular health and disease in man; and

(4) Gradual expansion of the research program to include other disease categories and other disciplines until, ultimately, the function of the station or centers is the full and complete investigation of the primate(s).⁵

No specific projects were discussed, most likely because nonhuman primates had never previously been proven useful for understanding chronic human diseases. Immediately following Watt’s presentation, National Institutes of Health Director James Shannon cautioned, “this report, which outlines certain potentialities, has not been studied as sufficiently as we would like in order to make firm recommendations at this time. I hope this can be done through the course of the next 6 to 8 months.”⁶ No such in-depth study was ever performed by the NIH, and, despite little scientific justification for developing costly primate research centers, sufficient political support existed to fund them. Although understanding atherosclerosis (hardening of the arteries, which leads to cardiovascular disease) had been a major impetus for the primate centers, Shannon acknowledged in 1963 that clinical research held much more promise:

The indications of current research findings that this [atherosclerosis] may be essentially a nutritional disease raise questions that cannot be satisfactorily answered in the laboratory. In fact, atherosclerosis is one of several areas in which research has reached the practical limits of laboratory investigation--with the present state of our knowledge and techniques. The road to further progress now seems to lie in large-scale and long-range epidemiological studies utilizing large population groups as the basic unit of study.⁷

Such studies were never undertaken. Rather, Congress followed the recommendation of leading academic heart disease researchers⁸ to establish primate centers to study this disease, and the federal government has been funding such laboratory research munificently ever since. This funding policy was not supported by two government-sponsored reviews of the primate center program conducted during the 1970s. The consulting firms questioned whether the benefits derived from the centers justified their costs, noting that none of the centers had earned the reputation as “the place to be” for scientists and that the centers’ core grants, which were not peer-reviewed, competitive grants, permitted some lower-quality research to proceed.⁹

In 1965, Yerkes’ great ape colony was transferred to Emory University in Atlanta to form the basis of a new regional primate research center. The first director of the new Yerkes center was nutritionist Geoffrey Bourne. It is clear from his autobiographical account of the early years at Yerkes that Bourne did not have a clear vision of how primate research might impact public health:

With the financing of the Yerkes Primate Center by public funds from Washington, it became necessary to define very explicitly what the function or mission of the Center was to be. Since it had a collection of great apes, it was obvious that the study of the great apes... was to become the most important activity of the new Primate Center....The mere study of the great apes themselves was likely to provide information that was valuable to human welfare simply because of their close relation to man.³

Neither Yerkes nor Bourne seriously questioned the relevance of their projects, because they assumed that their nonhuman primate research would apply to humans. However, this reflected a simplistic application of evolutionary theory, commonly expressed by other primate researchers, that other primates’ “closeness to man” legitimated nonhuman primate research.¹⁰ In fact, with few exceptions,¹¹ to this day primate researchers remain influenced by a theoretical framework that long predated Darwinian theory--the notion of a “Great Chain of Being.” This creationist-flavored notion posits that the animal kingdom is a continuum, from the simplest creatures to the most complex, humans, Nonhuman primates, according to such thinking, were the most “human’ animals. Modified slightly to account for Darwinian thought, early primatologists saw evolution as a linear process with simple organisms evolving into more complex ones. This kind of thinking has changed little to account for a more modem view of evolutionary theory, which sees evolutionary divergence more like a tree with branches representing different species, each of which has adapted differently biologically to survive in different environmental niches.¹² According to this framework, humans are not “superior” animals, but rather one of many species that has been successful for a variety of reasons. And, although humans and the great apes may be genetically and perhaps behaviorally very similar, sufficient differences nevertheless exist that reflect varying adaptations. For example, two leading primate researchers revealed their pre-Darwinian misconceptions in referring to “the chain of evolution.”¹³

Bourne’s research projects, like those of his successors, were influenced by Yerkes himself. As a result, behavioral research has always been a major focus at the Yerkes Center. Vision research, which involves the psychological phenomenon of a mental image, had been another of Yerkes’ early interests, and it, too, has remained a mainstay of the Yerkes Center. Many other areas of inquiry have reflected federal funding priorities, as Yerkes researchers have designed projects that have attempted to appeal to well-funded federal programs, such as cardiovascular research and AIDS.

The Yerkes Center has relied on public funds for nearly all its programs, and Yerkes officials have always justified the large federal grants by asserting substantial public health signiflcance~ Indeed, current Yerkes director Thomas Insel, discussing Yerkes’ response to animal protectionists, has stated:

To the extent that animal rights groups try to interfere with [Yerkes activities], we will deal with them as needed. However, the real defense of a place like Yerkes will come from the scientific discoveries that are made here and from the patients who will benefit from these discoveries.¹⁴

This defense will be explored with a review of typical Yerkes primate research projects, focussing on research that its public affairs officials have claimed to be relevant to the understanding and/or treatment of human conditions. ^15-17

1. Yerkes RM. A program of anthropoid research. American Journal of Psychology 1927;39: 18 1-199.

2. Haraway D. Primate Visions. Gender, Race, and Nature in the World of Modern Science. New York, Routledge, 1989.

3. Bourne GH. The Ape People. New York, GP Putnam and Sons, 1980.

4. Macleod CM, Meyer KF, Paul JR, Shimkin MB, Shope RE. The United States medical mission on microbiology and epidemiology to the Soviet Union. Journal of the American Medical Association 1956; 162:656-658.

5. Watt J. Feasibility and desirability of primate research centers. Testimony before the Departments of Labor and Health, Education, and Welfare Appropriations, Subcommittee of the Committee on Appropriations, United States Senate, Eighty-sixth Congress, First Session. Washington, United States Government Printing Office, 1959, pp 608-609.

6. Shannon JA. Testimony before the Departments of Labor and Health, Education, and Welfare Appropriations, Subcommittee of the Committee on Appropriations, United States Senate, Eighty-sixth Congress, First Session. Washington, United States Government Printing Office, 1959, p 609.

7. Shannon JA. Testimony before the Departments of Labor and Health, Education, and Welfare Appropriations, Subcommittee of the Committee on Appropriations, United States Senate, Eighty-seventh Congress, Second Session. Washington, United States Government Printing Office, 1962, p 1126.

8. Testimony before the Departments of Labor and Health, Education, and Welfare Appropriations, Subcommittee on Appropriations, United States Senate, Eighty-sixth Congress, First Session. Washington, United States Government Printing Office, 1959, pp 1281-1290.

9. Rowan AN. Of Mice, Models, & Men. Albany, SUNY Press, 1984.

10. Lewontin RC. Primate models of human traits.

11. Newell-Morris L, Fahrenbruch C. Practical and evolutionary considerations for use of the nonhuman primate model in prenatal research, in Nonhuman Primate Models for Human Growth and Development. New York, Alan R Liss, 1985.

12. Gould SJ. Ever Since Danvin: Reflections in Natural History. New York, WW Norton, 1977.

13. Brans YW, Kuehl TJ. Preface, in Nonhuman Primates in Perinatal Research. New York, John Wiley and Sons, 1988, pp xi-xii.

14. Skolnick AA. Neuroscientist/psychiatrist takes helm at flagship primate research center. Journal of the American Medical Association 1994;272:907-909.

15. Yerkes Regional Primate Research Center, Public Affairs Division. Annual Report: The 60th Year, 1989-1990. Atlanta, 1990.

16. Yerkes Regional Primate Research Center. Inside Yerkes. Atlanta, Spring 1993.

17. Yerkes Regional Primate Research Center. Inside Yerkes. Atlanta, Fall 1994.