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This review appeared in Volume 4 (3) of The Semiotic Review of Books.
Chimpanzee Material Culture: Implications for Human Evolution. By W.C. McGraw. Cambridge University Press. 1992. xv 277 pp. ISBN 0521423716.
Organisms are adapted to stable factors (such as gravity on) by morphology; towards regularly changed factors (such as seasons or circadian rhythms) by physiology, and towards irregularly and rapidly changed factors by behaviour. The appearance of behaviour as a form of adaptation is the result of a Gong process of evolution, and depends on the nervous system and the capability to be active and goal oriented in moving through space. (Leonovicova l992 8-9)
Ever since Jane Goodall (1963) first reported seeing chimpanzees break off twigs, strip off their side branches and insert them in termite mounds for the purpose of catching termites, the controversy about the making of tools and what this means in terms of the concept of culture has raged. For some the use of objects is a long observed phenomenon in animals such as sea otters and Egyptian vultures, who both use stones to break open enactable food items. One branch of this argument is that we look on tool use as a wonderful discovery mainly because it was observed in a primate, while other evidence of complex interaction between food item and food processing mechanisms such as gulls dropping mussels on rocks, are not recognized, due to lack of interest in the potential ramifications of gull behaviour.
W.C. McGrew has approached the problem of studying tool use in chimpanzees by embedding it in the larger question of how would you recognize culture in apes if you happened to observe it? He examines the main players of the book -- the wild chimpanzees of Africa, in the context of a larger group -- all the great apes both wild and captive as well as the technologically least complex humans. The continuum is extended by comparisons with monkeys, non-primate animals, birds and insects in an attempt to place chimpanzee cultural abilities in an evolutionary framework. The semantic problem of the definition of culture is initially bypassed until some observational evidence is presented.
In order to examine the problem McGrew begins by stating that "More like ourselves, and less like other animals, chimpanzees show flexibility of action that is apt for an apparently unlimited range of contexts" (2). It is this ability to adapt to an unlimited range of situations which has allowed humans to inherent the whole mind, due to their skills in accessing situations and modifying their resources in many ways to answer various needs. When studying behaviour in animals, the problem is to understand the source and range of whatever variability is present in their behaviour, it we are interested in looking for the roots of what we call culture in ourselves. As a source of data McGrew looks intensively at six major sites of chimpanzee field research in Africa, as well as drawing information from five shorter term studies. This data is used to set chimps in their context as apes and to compare what has been seen of their tool using ability with the other apes (Bonobo/pygmy, chimpanzee/orangutan, lowland gorilla/highland gorilla/gibbons) under both wild and captive conditions.
In chapter 4 the thorny problem of finding a testable definition of culture is addressed. Initially the evidence of sweet potato washing by Japanese macaques, and grooming styles by chimpanzees are examined in a discussion of whether social traditions in animals satisfy anthropological criteria well enough to be termed cultural. One position is to define culture as a human phenomenon, which ends the argument.
Evolutionists, on the other hand, seek the sources of human behaviour in the non-human past and search for those roots. Culture may now be the human econiche, but it did not necessarily begin that way. In search of the human past however we rely on artifacts that can survive over the time span in question and thus our focus is on tools. Therefore McGrew relied on a fist of criteria which operationalize culture (modelled from Krober's work) and looked for these characteristics in the tool use of chimpanzees. The list includes, Innovation, Dissemination, Standardization, Durability, Diffusion, and Tradition. In addition to these McGrew has added, Nonsubsistence and Naturalness. These last two disqualify the potato washing by Japanese macaques since it arose from human provisioning, and was food oriented. When examining chimpanzees, the first six criteria are met by termite fishing sticks and ant dipping sticks. It is probable that human intervention is not a major factor in these particular behaviours. However most well studied chimpanzee populations have been exposed to human influence by provisioning, or even because of watching local villagers crack palm nuts with a hammer and anvil in the way that some chimpanzee populations now do. Some chimpanzees do show non-subsistence behaviours with apparent social transmission, such as grooming with one arm in the air (Kasoke), and leaf clipping (as a courtship display). The examples given, however, suggest that no chimpanzee population shows behaviour which clearly satisfy all eight criteria. The question, then is whether this precludes defining chimpanzee tool use as a cultural phenomenon. Current controversy over imitation and teaching rage among primate researchers, with experimental data gathered with captive animals being used to argue that everything wild chimpanzees do, captures ones can invent for themselves (Tomasello 1990). McGrew disagrees with this conclusion and adds that even if it were true, it says nothing about how behaviour develops and spreads in the wild. Other researchers (e.g. Washburn & Benedict 1979) argue that cultural transmission cannot occur without language, but this is clearly another conception of culture. Part of this viewpoint arises from the position that behaviour must have 'meaning' before it is cultural. To demonstrate this for primates would be an enormous challenge, as, incidentally, it would be for many human cultural behaviours. McGrew leaves the question of definition by showing close similarities between human and chimpanzee behaviour and asking how behaviour occurring in chimpanzees would be categorized if it were observed in a human group.
He goes on to examine the culture question by looking at gender differences in food acquisition patterns in chimpanzees. If clear differences between males and females are evident in what kind of food is eaten, and how it is acquired, does this suggest cultural influence in feeding strategy. The conclusion that females eat more insects, because the behaviour is quite compatible with infant care, since the actively is localized, repeatable and fairly safe while males chase, kill and eat more meat, reveals a pattern much like the division of human gathering and hunting. The question becomes: Is this mainly a function of child care, or does it reflect different nutritional needs by adult chimpanzees? Given the eagerness with which female chimpanzees beg for meat if it is available, and the fact that Gigi, a non-reproductive female, went hunting frequently with the males, the difference seems more likely to be a social strategy than a biological one. Sex differences are also evident in chimpanzee nut-cracking with females often being more successful and efficient nut crackers. Food sharing is another behaviour which shows differences by sex, with males most frequently giving food to females, and females to their young. This is seen for bananas, fruit, meat and cracked nuts. With this division of activity established, the obvious comparison of chimpanzees and human hunter-gatherers is undertaken. Briefly, the main differences are the very low level of tool use, including containers, and the lack of moving resources to a centralized location to share, shown by chimpanzees. The problem of a direct comparison is impeded by the fact that current apes and human hunter gatherers no longer share forests in unacculturated states. The comparison McGrew makes between tool use by now extinct Tasmanian hunter-gatherers and chimpanzees is a very interesting one because it draws on a human population with a very simple technology which was studied over a long time in an observational manner reasonably comparable to the chimpanzee studies. A pattern including object use, tool use, and level of tending a food-procuring facility, was set up and served as a framework of comparison for the two populations. Many parallels between the groups were noted, such as the type of material used, the simple (as opposed to complex) nature of the tools, and the tended nature of food procurement facilities. Clear differences are also evident, particularly in the use of fire, manipulative skills such as knot tying, and use of untended traps. Also, a number of human tools were made with the use of other tools. These differences provide clues concerning areas of focus in looking for the bridges from non-human to human cultural patterns. The small size of some of these gaps (especially considering that captive apes can learn to use fire) allows us to construct a hypothetical series of steps from one pattern to the next and to know what kind of evidence we are looking for.
The third major section of this book, after defining culture and comparing chimpanzees with other apes and with humans, focuses on the variability of chimpanzee behaviour. Comparisons are made between major study sites, examining evidence for meat eating, insectivore, and stones used as anvils and hammers for cracking nuts. The different food species and the manner in which they are exploited are tested for a variety of habitats and the variation between them examined for evidence of ecological determinism. In some cases environmental factors do seem to be the basis for observed variability, whereas in other situations differences are "more likely to be understood in terms of the social milieu." (173) The patterns of tool use derived from these observations are compared with what is known from captive animals with the discovery that no pattern is universal. However, functional similarities, especially in subsistence activities, are quite widespread. Thus, although the tasks are similar, differing regional and local tool patterns for solving problems show internal consistency and time depth. While this is interesting from a cultural perspective, the source of these differences is even more interesting. Are the chimpanzees learning from observing humans? Are they diffusing behaviour patterns from one region to the next? Do they have environmental differences in substrate to work with?, or are true innovations occurring? The latter, which would be the strongest argument for culture, is the most difficult to prove since the observer would have to see the first episode of a new pattern, and be able to demonstrate that it was the innovative episode. As McGrew asks: "how many studies of foraging people in situ however long term, have ever reported spontaneous invention of new tools?" (195). Thus clear evidence of this type of invention is lacking even though hypotheses can be constructed about how certain use patterns might have originated.
Out of all the evidence for tool use compiled, only the hammer and anvil nut crushers are at all comparable with archaeological evidence for early tool use in humans. This is a very small part of the current assessment of what chimpanzees are capable of. If chimpanzees are to form a productive model, perhaps the most useful aspect is to become aware of the wide range of variability in habit patterns within one species for solving similar problems technologically. Why should all early hominids have solved problems in the same way over the range of environments they inhabited? Do we know what we don't know about the non-lithic tool use potential of early hominids? What types of evidence are necessary to make a clear assessment of cultural transmission of behaviour? Can behavioral patterns, such as sexual difference in food-procuring activity, be proposed as underpinnings to such pervasive human cultural patterns as the sexual division of labour?
These questions are at least raised by this book and the use of chimpanzees as models for the study of early hominds examined in the light of both our knowledge of chimpanzee variability and our realization that there is a lot we do not know about them. The book concludes that chimpanzees do not have human culture, even though many aspects of their activities may be indistinguishable from the result of human endeavour. If you can't tell the difference in tools without a label, can you argue that one population of makers has a cultural basis while the other does not? It is not the extent, the range, or the complexity of the behaviour that is at issue, it is the nature of the behaviour.
Although the conclusion seems a little thin, the questions raised by this book are fascinating. Bill McGrew has provided a wealth of comparative evidence on chimpanzee life and demonstrated a huge range of variability in their subsistence behaviour. His placement of chimpanzees in higher primate perspective, and the comparisons he draws with human cultures provide us with links in a chain of evidence binding humans to their prehuman past.
It should be mentioned here that McGrew's repeated references to Tasmanian Aborigines in this context has been considered offensive by some. As William Noble and Ian Davidson point out in Man 26, 2 (1991) P.247: "Although their ancestors were undoubtedly persecuted (...), they were not exterminated, and modern Tasmanians play pianos, drive cars, and participate in all other ways in society with other humans, options not open to any modern chimpanzees (...). We do not believe that cross-species comparisons are necessarily offensive to the human species (...) and McGrew certainly did not intend that his comparison should be. Our analysis of it reinforces an intuitively obvious difference: THE Tasmanian tool-kit may have been the simplest ever made by humans, but the technology was significantly more complex than anything shown to have been achieved by free-living or captive chimpanzees".
Goodall, J. 1963. Feeding behaviour of Wild Chimpanzees. Symposia of the Zoological Society of London.
Leonovicova, V. 1992. "The sociobiological perspectives in the study of human evolution." Journal of Human Evolution. Vol. 7, 4 (7 14).
Tomasello, M. 1990. "Cultural transmission in the tool use and communicatory signalling of chimpanzees?" In Language and Intelligence in Monkeys and Apes. S.T. Parker and K.R. Gibson (Eds ) Cambridge: Cambridge University Press. (274-311).
Washburn, S.L. and Benedict, B. 1979. "Non-human primate culture." Man 14 (163-164).
Anne Zeller is an Associate Professor in the Department of Anthropology at the University of Waterloo (Canada). She has recently been conducting fieldwork in Indonesia (Kalimantan) on the adult-infant social relations in Macaca fascicularis (crab-eating macaque). She is the author of a study of visual and vocal communication in Macaca sylvanus in Primates: recherches actuelles. J.J. Roeder and J.R. Anderson (eds.) Paris: Masson (1990). Among her other publications are: "Comparison of component patterns in threatening and friendly gestures in Macaca sylvanus of Gibraltar", in Current perspectives in Primate Social Dynamics. D.M. Taub and F.A. King (eds.) New York: Van Nostrand Reinhold Press, 1986. (487-504); "Primate Facial Gestures: A Study of Communication". International Journal of Human Communication (1980) 13.4:565-606.