Primatology


Primatology is the scientific study of primates. Unlike branches of zoology focused on specific animal groups, primatology – and the primate order — includes both human and nonhuman animals. Thus, the field entails significant overlap with anthropology, the study of humans, and related sciences.
Primatology encompasses a broad swath of scientists from different fields of study, each with distinct perspectives. For example, behavioral ecologists may focus on ways primate species act in different environments or circumstances. Sociobiologists are concerned with genetic inheritance and primates' physical and behavioral traits. Anthropologists tend to focus on humans' evolutionary history; they look to primates for greater insights into how Homo Sapiens have evolved. Comparative psychologists study differences between human and nonhuman primate minds.
Some primatologists work in the field to study animals in their natural environments; others work in academia in labs conducting experiments. Many do a mix of both. In the 21st century, primatologists have often blended approaches, incorporating both experimentation and observational data to varying degrees.
Many primatologists work outside of academia. In places where nonhuman primates are indigenous — Asia, Africa, and South America — they often work in government to balance human-wildlife coexistence and promote conservation. Primatologists also work in animal sanctuaries, NGOs, biomedical research facilities, museums and zoos.

21st century "primatologies"

Primatology was established as a discipline in the 1950s in America/Europe and in Japan. International programs — in South America, Africa, and other parts of Asia — began taking off in the 1970s.
Given the wide variety of disciplines involving primates, some specialists speak of primatology not as a single discipline but of multidisciplinary "primatologies." Primatology in the U.S. largely originated with anthropology and its strong bent toward understanding humans and defining human uniqueness. In contrast, "establishing the human-animal divide is generally of little importance to non-Western primatologies."
Researchers from Brazil, India, Vietnam, Africa and areas with indigenous primates have adopted many Western practices while focusing on objectives and approaches that reflect local challenges and cultural traditions. Human populations in these countries have different relationships and experiences with wild primates than do those in the West. The human-primate "interface" is thus a key point of research. Population dynamics, with repeated conservation surveys, form a significant part of research activities for Indian primatologists, for example. Primate rescue centers are key research hubs in Vietnam. Ecology, demography, human-wildlife conflict, and conservation of interconnected species and ecosystems are all possible focal points.
Ethnoprimatology is a 21st-century subdiscipline focused on the social, cultural, and ecological contexts of human-primate interactions. As habitat loss continues to worsen internationally, primatologists Agustin Fuentes and Kimberley J. Hockings state that understanding which primates are best able to adapt and interface with human populations, and how they are able to do so, is a new frontier for primatology.

History

Early roots in the West

Primate research has its roots back several centuries. Linnaeus named Primates in 1758, placing Homo in the same taxonomic order as monkeys, apes, lemurs, and bats. This was later revised, and the order primates now includes strepsirrhines and haplorhines.
Charles Darwin's books On the Origin of Species and The Descent of Man drew widespread attention to humans' closest relatives. His theory of evolution ignited public fascination with the relationship between humans and monkeys, even a "gorilla craze." Zoologists Ramona and Desmond Morris later credited Darwin for setting off two major trends. One: By connecting humans with other animals, Darwin prompted researchers to consider the behaviour of living animals, especially monkeys and apes, as worthy of detailed scientific study. Two: Researchers inspired by Darwin became prone to highly anthropomorphic interpretations of animal behavior. Once animals were seen as related to humanity, they were viewed as potentially highly rational creatures with exalted moral codes.
Richard Garner, arguably among the first dedicated primate field researchers, personified this tendency. Garner was an innovator in some ways: he built a cage in the African forest to study gorillas in their natural habitat. He recorded primate vocalizations and tested the animal's responses when played back. But his writings included anthropomorphized claims about monkey and ape "speech," stories that provided fodder for outlandish newspaper headlines and illustrations.
While scientists from the late-19th and early-20th century were deeply interested in researching evolution, they were wary of being seen as peddling Garner-style primate folklore."  In the early 1900s, many Western researchers discounted observational studies as unprofessional and uncontrolled. They viewed lab experiments as the scientific ideal but faced serious complications in building out spaces suitable for primates. Primates are not indigenous to Europe or North America and importing them was expensive.
More significantly, those hoping to study primates struggled to keep animals alive. The experience of American scientist Robert Yerkes is illustrative. Yerkes spent $2,000 in 1923 — most of his life savings at that point — to buy his first two ape study subjects, Chim and Panzee. Within 5 months, Panzee was dead, and by 12 months, Chim was too. From 1837 to 1965, the average primate in zoos survived about 18 months. Given that apes take a decade or more to reach adulthood, the poor care practices for captive animals meant that studies were bound to be short-term and largely restricted to juveniles.
Yerkes improved his animal care methods after traveling to Cuba to visit wealthy animal-keeper Rosalía Abreu, the first person to successfully breed chimpanzees in captivity. He documented Abreu's practices in Almost Human, in which he identified several factors to improve captive primate care: socially house animals in large, clean spaces with a choice of shade or sunlight; fresh air; sunlight; a varied, appropriate diet and, where possible, space for exercise.
Other early pioneers of primate research include:
  • Clarence Ray Carpenter, an American student of Yerkes, was one of the first researchers to scientifically record the behavior of wild primates in the 1930s; He established rigorous methodologies for field scientists to follow.
  • Wolfgang Kohler, a German psychologist who conducted seminal experiments on ape cognition, described in his classic The Mentality of Apes.
  • Élie Metchnikoff, a Russian immunologist, in 1903 used chimpanzees and orangutans as the first reliable animal models for studying the progression and treatment of human disease, in this case, syphilus.

    Racism in primate research

Primate research before the 1950s had roots in eugenics and scientific racism, reflecting and amplifying racist tropes in Western popular culture. Robert Yerkes, often considered the founder of American primatology, promoted primate research in 1925 by arguing that it was the most practical way to "wisely and effectively regulate or control individual, social, and racial existence."  It was practical, he argued, because one could conduct experiments on apes relatively efficiently without "risk of social censure or legal infringement."
Yerkes was a key American promoter of eugenics, an ideology intended to improve the genetic quality of the human race. Eugenics became hotly criticized and, in the US, started to wane in the 1920s. In effect, Yerkes worked to build a new discipline on the remains of an old one.
Yerkes was far from alone in this effort. Konrad Lorenz, an Austrian zoologist whose work heavily influenced the development of European primatology, was also an advocate of eugenics. In the early 1940s, Lorenz defended Nazi efforts to prevent interbreeding of different human "races." Richard Garner, the attention-seeking professor of "monkey talk" mentioned above, used his platforms to promote white supremacy in the late 1890s and early 1900s. F.G. Crookshank, a Fellow of Britain's Royal College of Physicians, published a book in 1924 claiming that white people descended from chimpanzees, Black people from gorillas, and "yellow" people from orangutans. Crookshank, in line with other racial pseudoscientists, argued that racial "mixing" was dangerous and destructive to the white race.
Significant change to anthropology — and, thus, primate research — came after WWII and the Nazi Holocaust. In the wake of Nazi atrocities perpetrated by beliefs about racial superiority, sciences studying humankind shifted dramatically away from differences between races. Instead, scientists began stressing the unity of the human species. The "new physical anthropology" promoted by Sherwood Washburn, a pioneer in baboon studies, had an antiracist ethos.
But while explicit racism in mainstream science waned after WWII, primatology's racist roots have continued to impact the field. Donna Haraway drew attention to the legacy of racism and sexism in primatology in her critical history of the field, Primate Visions. In 2023, the American Journal of Biological Anthropology published an editorial by Thomas C. Wilson, a Black primatologist, outlining ways that the field's racist legacy negatively impacts contemporary research.

Establishing primatology in Japan

Primatology emerged as its own distinctive field in the 1950s. That decade saw the rise of primatology simultaneously — and largely independently — in both Japan and in the West. Over time, the traditions blended, but Japanese scientific practice initially differed from that of the Darwin-centered, objectivity-focused researchers overseas. The relationship between humans and other living beings was a deep-seated part of Japanese cultural and intellectual traditions, while the quest for objectivity was not. Japanese scientists assumed monkeys were thinking animals because nonthinking doesn't make sense from an evolutionary perspective. "The problem of mind" in animals was not a problem for the Japanese in the way it was for Western scholars. This opened up Japanese studies to criticism of anthropomorphism and bias, even in cases where their ideas later proved correct.
Unlike Europe and the US, Japan was home to an indigenous monkey species, Japanese macaques, making it relatively easy to observe subjects in the wild. In the 1950s, the tropical areas where most primates live were very difficult for outsiders to access. So while primatology in the West focused on animals in captivity, Japanese scientists focused on field research.
Kinji Imanishi and Junichiro Itani, founders of Japanese primatology, studied primate social groups, seeking insights into the origins of human society. They pioneered the following distinct techniques:
  • Provisioning: Researchers provided food for the monkeys as a short-cut to habituate them, making them easier to observe. This practice was later discouraged out of concerns that it warps natural behaviors.
  • Individual identification: Learning to identify every monkey in a troop as an individual was seen as key to understanding the group's dynamics. Japanese researchers also identified primate "personalities."
  • Long-term studies over many years and multiple generations were considered necessary to understand group dynamics and society.
The first scientific journal focused on primate research, Primates, was published in Japan in 1957, with English translations. More Japanese studies were translated into English in the 1960s, where they eventually found an audience in the West. Many of their findings — regarding dominance hierarchies, matrilineal residence, the existence of a breeding season — provided foundational understandings of primate socialization internationally.
Perhaps the most widely popularized reports of Japanese origin were those regarding macaque proto-culture. In 1954, Satsue Mito, a field assistant, noticed that one of the female monkeys washed her sweet potatoes before eating them — and that other monkeys in the group were copying the habit. This led researchers to explore how learned behaviors spread in populations, eventually igniting debates around monkey and ape "culture," a subject popularized in the U.S. by Frans de Waal in The Ape and the Sushi Master.
Imanishi and Itani went on to co-found the Primate Research Institute at Kyoto University in 1967.