Primate archaeology is a field of research established in 2008 that combines research interests and foci from primatology and archaeology. The main aim of primate archaeology is to study behavior of extant and extinct primates and the associated material records. The discipline attempts to move beyond archaeology's anthropocentric perspective by placing the focus on both past and present primate tool use.
Primate archaeology is characterized by the combination of archaeological and primatological methods, and researchers consider both non-human primate tools and their behaviour in tandem.Carvalho, S. and Almeida-Warren, K., (2019). Primate archaeology. In Encyclopedia of animal behavior. Academic Press, 397–407. Primate archaeology has the unique opportunity to observe the tool-use behaviors of extant non-human primates and the formation of the material record that emerges from that behavior. It is this ability to observe behavior and the subsequent material deposition resulting in a material record recoverable using standard archaeological field methods that gives this new field of research the possibility of reconstructing, predicting, and interpreting extant primates' tool use spatial patterns.
Interpretations of material culture should not assume that behavioural patterns are necessarily cultural, or that culture exists in only one form. Cultural explanations, and the type of cultural transmission involved, need to be distinguished from alternative and interacting influences such as ecology, genetics, individual learning and ontogeny. These factors can jointly shape tool-use behaviour, making simple cultural/non-cultural dichotomies potentially misleading. Overall, primate archaeology helps researchers understand how early hominins used material culture, what these patterns reveal about ancient hominin cognition, as well as patterns of landscape use that could allow researchers to identify behaviors that are difficult to detect archaeologically. Primate archaeology's main focus is on the study of the non-human primates that have been observed using tools in the wild: chimpanzees (Pan troglodytes), robust capuchins (Sapajus spp.) and long-tailed macaques (Macaca fascicularis aurea). Since its conception primate archaeology has also implemented the use of captive studies akin to archaeological experiments with non-human primates looking into stone tool manufacture.
Origins The establishment of primate archaeology as an official discipline took place around 2008 and 2009. However, the two-fold nature of this relatively new subject area can be traced back to some major events in the development of both archaeology and primatology.
Archaeology The search for the earliest evidence of material culture in the archaeological record has been one of archaeology's major aims almost since its inception as a discipline. With the classification of stone tools as human-made artifacts and not fossils, towards the end of the seventeenth century, stone tools soon became key evidence for arranging the archaeological record into sequential cultural phases. The discovery of Eoliths, which were thought to be flint tools in the Oligocene deposits of Thenay in France led to the establishment of the Eolithic culture and Homopithecus bourgeoisi. The Eolithic tools were described as being directly used in their natural state or being poorly worked. Although some influential scholars tried to discredit the Eolith hypothesis,Warren, S. H., 1905. On the origin of Eoliths. Man, 5, 179-183. the discovery of the Piltdown Man in 1912 only helped to reinforce its credibility because the fossil remains were found in association with Eolithic tools.Dawson, C. and Woodward, A.S., 1913. On the discovery of a Palaeolithic human skull and mandible in a flint-bearing gravel overlying the Wealden (Hastings Beds) at Piltdown, Fletching (Sussex). Quarterly journal of the geological society, 69(1-4), pp.117-123. Both the Eolithic culture and Piltdown man remained controversial until they were finally discredited around the 1950s.
Disregarding the Eolithic controversy, the earliest stone tools (also found in the European continent) were the Chellean being followed by the Acheulean. Thus, before the twentieth century, most archaeologists believed that Europe was where hominins began to use and manufacture stone tools. However, this narrative began to change when in 1931 Louis Leakey discovered in Olduvai Gorge stone tools that seemed to be older than those found in Europe. Soon after, Leakey formally named this discovery the Oldowan industry.Leakey L. S. B. (1934). The sequence of Stone Age cultures in east Africa. In Evans-Pritchard E. E., Firth R., Malinowski B., Schapera I. (Eds.) Essays presented to CG Seligman. London, UK: Kegan Paul, Trench, Trubner & Co. Limited, pp. 143-146. Decades later, Oldupai was the focus of two more major findings. First, in 1959 a skull identified as Zinjanthropus (now Paranthropus) boisei was found near Oldowan stone tools, and this led to the argument that this hominin could be a direct ancestor of modern humans. However, in 1964 a new fossil (OH 7) was also found in association with the aforementioned stone tools.Leakey L. S. B., Tobias P. V., Napier J. R. (1964). A new species of the genus Homo from Olduvai Gorge. Nature 202: 5–7. The connection of this hominin with Oldowan stone tools and the fact that it seemed to have a larger brain than the australopiths led to its classification as Homo habilis (meaning "the handyman") and the assumption that stone tools were a distinctive feature of the genus Homo. The idea that the use of (stone) tools, and thus culture, was a unique characteristic of the genus Homo was not empirically challenged until 2010 and 2015 with the discovery of what could be the earliest archaeological evidence of cut-marked bones and stone tools respectively. However, the classification of H. habilis as part of the genus Homo became controversial soon after its discovery due to the use of cultural traits to justify hominin taxonomy.Wood, B. and Collard, M., (1999). The changing face of genus Homo. Evolutionary Anthropology: Issues, News, and Reviews: Issues, News, and Reviews, 8(6): 195-207. Recently, the idea that human ancestors have been responsible for intentionally making stone tools has also been put into question through primate archaeology research.
Towards the end of the twentieth-century, archaeology shifted from a focus on typological classifications towards an interest in understanding the mechanisms behind the origins and subsequent evolution of stone tools. This conceptual turn led to the initial establishment of experiments bringing archaeology and primatology together. Inspired by Jane Goodall's report of chimpanzee tool use, in 1972 Wright decided to teach a captive orangutan (Pongo pygmaeus) named Abang to make Oldowan flakes by striking a flint core to then use the flakes to open a box through imitative learning and some hand molding.Wright, R.V., (1972). Imitative learning of a flaked stone technology-the case of an orangutan. The Australian Journal of Anthropology, 8(4): 296-306. Abang was capable of making and using the flakes only after multiple trials and not very efficiently, yet it has been suggested that this inefficiency could be the result of his upbringing in captivity. A couple of decades later, Kathy Schick and Nicholas Toth developed a similar experiment initially with a single captive, enculturated bonobo (Pan paniscus) named Kanzi to see whether he could copy Oldowan stone tool making. In subsequent experiments, more enculturatd bonobos started to make and use stone tools after seeing Kanzi. The skills of these bonobos were said to be rudimentary, and even though they were taught to use freehand knapping (one stone core is held in one hand and another stone in the other hand) their preferred method to make flakes involved throwing the stone core against a hard surface. In 1994, Westergaard and Suomi decided to redo the Abang and Kanzi type of experiments but this time they ran a baseline study (no demonstrations) with a group of unenculturated monkeys - capuchins (Sapajus [Cebus] apella). These capuchins had no exposure to stone tool making prior or during the study, and they were unenculturated - and so anystone tool use they would show should therefore be considered spontaneous. In this experiment, the unenculturated capuchins spontaneously began to produce flakes by striking stones against hard surfaces. Like Kanzi, they did not use the freehand knapping technique normally associated with the Oldowan. Researchers did not attempt further experiments involving non-human primates trying to make and use stone tools until around 2020 - when further baseline studies were run, this time with a focus on the performance of unenculturated apes. In this way, orangutans got tested, as did chimpanzees https://open-research-europe.ec.europa.eu/articles/1-20/v2 and gorillas. These experiments combined the use of baselines with that of demonstration conditions.
Primatology
Although there are prior examples of studies looking into non-human primates across Western countries,Köhler W., (1925). The Mentality of Apes. Kegan Paul, Trench and Trubner, London. the modern study of primate behavior originated in Japan. The first international journal in primatology, Primates, was created in Japan in 1957. Japanese primatology was established through the observation of free-ranging Japanese macaques (Macaca fuscata) by Jun'ichiro Itani, Kinji Imanishi and Shunzo Kawamura. The main aim of these first primatologists was to understand the social structure of the macaques groups they were observing. Following their prior expertise in the individual identification of wild horses, they began to give nicknames to each monkey. Furthermore, to habituate the monkeys to their presence, they began to give them food while they established a long-term observation method. A few years later, in one of the Japanese macaque sites, a young female, later nicknamed "Imo", was observed washing a sweet potato in a small stream. After this instance, Kawamura began more systematic observations of this behavior discovering the propagation of sweet-potato washing among other members of the group. As a result of the sweet-potato washing phenomenon, Japanese primatologists started to draw the first direct associations of the terms culture and subculture in association with non-human animals.Kawamura, S., 1959. The process of sub-culture propagation among Japanese macaques. Primates, 2(1), pp.43-60. Another major contribution of Japanese primatology took place with the foundation in 1978 of the ape-language project (later named Ai project) at the Primate Research Institute of Kyoto University with the collaboration of Kiyoko Murofushi, Toshio Asano and Tetsuro Matsuzawa. Although the Ai project had a focus on language acquisition their methods emphasized the cognitive capabilities more than the communicative skills of the monkeys. Through projects of this kind, Japanese primatology highlighted the importance of merging both field and experimental settings for the study of primate behavior and cognition.
The contributions of paleoanthropologist and archaeologist Louis Leakey are also notable in the field of primatology. Leakey believed in the importance of studying non-human primates to better understand human evolution. It was Leakey who encouraged Jane Goodall, Dian Fossey, and Birutė Galdikas to study chimpanzee, gorilla, and orangutan socioecology and behavior. Goodall, Fossey, and Galdikas pioneered the establishment of long-term primatological sites in which the habituation of the primates through trust was of key importance. Their work continues to leave an impact on the way non-human primate sites are managed, as well as on the study of behavioral connections between non-human primates and early humans.