The use of chimpanzees in laboratory research represents a distinct chapter in biomedical and behavioral science. Their genetic makeup, sharing approximately 98 to 99 percent of DNA with humans, positioned them as subjects for understanding human health and disease. This biological proximity led scientists to believe that chimpanzees would react to various pathogens and treatments in ways closely mirroring human responses. For decades, these highly intelligent primates were utilized in studies aimed at advancing medical knowledge and addressing significant human health challenges.
The Scientific Rationale for Using Chimpanzees
Historically, chimpanzees were considered models for certain human diseases due to their unique susceptibility to specific pathogens. They were the only nonhuman species known to contract the human hepatitis B virus (HBV), making them instrumental in developing the Hepatitis B vaccine and understanding its interaction with a host. Early in the HIV/AIDS epidemic, chimpanzees were also deemed the most suitable animal model because they could be infected with the human immunodeficiency virus (HIV), though they rarely progressed to developing AIDS, which limited their long-term utility for this specific disease.
Chimpanzees also played a role in the United States’ space program. In the 1950s, the U.S. Air Force used them to investigate the physiological effects of spaceflight, including G-force exposure, as part of preparations for human space missions.
The Ethical Controversy and Decline
As scientific understanding of chimpanzees deepened, so did the ethical questions surrounding their use in laboratories. Researchers and primatologists, notably Jane Goodall, illuminated the complex cognitive abilities, intricate social structures, and emotional lives of these animals. It became clear that chimpanzees possess individual personalities, engage in problem-solving, and experience emotions, indicating a capacity for both mental and physical suffering. Confining such sentient beings in often barren, isolated laboratory environments for extended periods, sometimes decades, was increasingly viewed as morally unacceptable.
The very genetic and behavioral similarities that made chimpanzees valuable research subjects also underpinned the ethical arguments against their use. Animal welfare organizations and a growing public awareness highlighted the psychological trauma and physical distress many laboratory chimpanzees endured, leading to abnormal behaviors like repetitive movements or self-harm. The argument was raised that their close resemblance to humans meant they deserved greater moral consideration and protection from invasive procedures and lifelong confinement. This evolving perspective ultimately challenged the scientific justification for their continued use.
The End of an Era in Research
The shift away from chimpanzee research in the United States was solidified through a series of policy and legislative actions. In December 2011, a report from the Institute of Medicine (IOM), commissioned by the National Institutes of Health (NIH), concluded that most ongoing biomedical research involving chimpanzees was no longer necessary. The report stipulated that any future use of chimpanzees in research would need to meet exceptionally strict criteria. Following this report, the NIH immediately suspended funding for new chimpanzee research grants and began re-evaluating existing projects.
By June 2013, the NIH announced its intention to retire the vast majority of its federally owned chimpanzees. In November 2015, it declared it would cease all support for biomedical research on chimpanzees, with all remaining federally owned animals becoming eligible for sanctuary retirement. These actions were supported by the Chimpanzee Health Improvement, Maintenance, and Protection (CHIMP) Act, initially passed in December 2000, which established a federal sanctuary system for retired research chimpanzees. A further significant step occurred on September 14, 2015, when the U.S. Fish and Wildlife Service (FWS) granted full Endangered Species Act (ESA) protections to all chimpanzees, both wild and captive. This change ended a “split listing” that had previously allowed captive chimpanzees to be used in research, and the new endangered status created substantial regulatory barriers, effectively prohibiting most remaining private research.
Life After the Lab
Following the cessation of widespread research, many chimpanzees have transitioned from laboratory settings to dedicated sanctuaries. Chimp Haven, a 200-acre facility in Louisiana, serves as the primary federal sanctuary for these retired animals, with others finding homes at places like Project Chimps in Georgia. This move aims to provide them with a more naturalistic and enriching environment for the remainder of their lives. The first chimpanzees arrived at Chimp Haven in 2005.
The transition to sanctuary life presents unique challenges for these chimpanzees. Many spent years, sometimes decades, in isolation or small, artificial groups, requiring extensive efforts to help them learn how to socialize within larger, more complex chimpanzee communities. Some retired chimps exhibit behaviors indicative of psychological trauma, such as repetitive actions or difficulty forming bonds, which require specialized behavioral enrichment and care from dedicated staff. Additionally, many arrive with chronic health issues, necessitating ongoing veterinary attention for their long lifespans, which can extend into their 60s. Providing this comprehensive, lifelong care is resource-intensive, with costs estimated at tens of thousands of dollars per chimpanzee annually, supported by a combination of federal funds and public donations.