Intensification, Tipping Points, and Social Change in a Coupled Forager-Resource System

This paper presents a stylized bioeconomic model of hunter-gatherer foraging effort designed to study the process of intensification on open-access resources. A critical insight derived from the model is that the very success of an adaptation at the level of an individual forager group can create system-level vulnerabilities that subsequently feed back to cause emergent social change. The model illustrates how the intensification of harvest time by individuals within a habitat creates a forager-resource system that becomes vulnerable to perturbations. When the system is vulnerable, it is characterized by two resource harvest equilibria: a sustainable, low-effort equilibrium and a degraded, high-effort equilibrium. In this situation, the forager-resource system can be shocked back and forth between these different equilibria by perturbations, generating considerable risk for foragers. We use the model to isolate the ecological conditions under which the instability of the system generates the risk that foragers will experience a shortfall of resources, and we suggest a mechanism that might lead foragers to adopt social institutions that regulate who can access a habitat as an adaptive response. As an illustration of the potential utility of the insights drawn from the model, comparisons are made with a substantial ethnographic data set.     

Eating, exercise, and "thrifty" genotypes: connecting the dots toward an evolutionary understanding of modern chronic diseases.

Survival of Homo sapiens during evolution was dependent on the procurement of food, which in turn was dependent on physical activity. However, food supply was never consistent. Thus it is contended that the ancient hunter-gatherer had cycles of feast and famine, punctuated with obligate periods of physical activity and rest. Hence, gene selection in the Late-Paleolithic era was probably influenced by physical activity and rest. To ensure survival during periods of famine, certain genes evolved to regulate efficient intake and utilization of fuel stores. Such genes were termed "thrifty genes" in 1962. Furthermore, convincing evidence shows that this ancient genome has remained essentially unchanged over the past 10,000 years and certainly not changed in the past 40-100 years. Although the absolute caloric intake of modern-day humans is likely lower compared with our hunter-gatherer ancestors, it is nevertheless in positive caloric balance in the majority of the US adult population mainly due to the increased sedentary lifestyle in present society. We contend that the combination of continuous food abundance and physical inactivity eliminates the evolutionarily programmed biochemical cycles emanating from feast-famine and physical activity-rest cycles, which in turn abrogates the cycling of certain metabolic processes, ultimately resulting in metabolic derangements such as obesity and Type 2 diabetes. In this context, we postulate that perhaps a crucial mechanism to break the stall of the metabolic processes would be via exercise through the regulation of "physical activity genes," some of which may also be potential candidates for the "thrifty genes" of our hunter-gatherer ancestors. Therefore, the identification of such "thrifty gene" candidates would help provide insight into the pathogenetic processes of the numerous physical inactivity-mediated disorders.     

The Ecology of Wealth-in-People: Agriculture, Settlement, and Society on the Perpetual Frontier

For the Susu of northwestern Sierra Leone, rural settlement dynamics reflect a frontier culture history and the perpetuation of frontier sociopolitical arrangements in village life. Under frontier conditions people are wealth. The competition among male elders for wealth-in-people is a major determinant of village movements and the organization and deployment of agricultural labor. In this article, I explore the implications of frontier social arrangements, as illustrated in the careers and lives of individual elder men, for the ecology of swidden agriculture. One significant result is a competitive scramble for labor, which both hinders crop production and leads to problems of intensification and resource degradation. I conclude that local problems of resource management are the result of individual efforts to achieve and maintain social position in the context of established systems of hierarchy.     

"Craziness" and "visions": experiences after a stroke.

For a stroke victim there may be at least three types of strange occurrences: incorrect saying, seeing, and thinking. To the patient only the third seems to be "crazy". After a stroke (left hemisphere), which mainly produced serious aphasia, I (the patient) felt crazy two or three times when someone said something I expected him to say. On the other hand, my initial aphasic "gibberish speech" and an occasional false vision did not seem crazy. In my case the vision is always a car or a child, seen on my extreme right, where I am otherwise blind from the stroke. I am always driving when it happens; in recent years this phenomenon occurs when I am tired or tense, or the light is poor. These rapid visions do not seem insane but merely physical problems in my eyes, much like ordinary people''s dreams.     

The complex structure of hunter-gatherer social networks

In nature, many different types of complex system form hierarchical, self-similar or fractal-like structures that have evolved to maximize internal efficiency. In this paper, we ask whether hunter-gatherer societies show similar structural properties. We use fractal network theory to analyse the statistical structure of 1189 social groups in 339 hunter-gatherer societies from a published compilation of ethnographies. We show that population structure is indeed self-similar or fractal-like with the number of individuals or groups belonging to each successively higher level of organization exhibiting a constant ratio close to 4. Further, despite the wide ecological, cultural and historical diversity of hunter-gatherer societies, this remarkable self-similarity holds both within and across cultures and continents. We show that the branching ratio is related to density-dependent reproduction in complex environments and hypothesize that the general pattern of hierarchical organization reflects the self-similar properties of the networks and the underlying cohesive and disruptive forces that govern the flow of material resources, genes and non-genetic information within and between social groups. Our results offer insight into the energetics of human sociality and suggest that human social networks self-organize in response to similar optimization principles found behind the formation of many complex systems in nature.     

Feasting, Craft Specialization, and the Ritual Mode of Production in Small-Scale Societies

Economic intensification has been documented in a diversity of small-scale societies. The existing archaeological theory concerning such intensification has tended to privilege economic and political explanations and largely ignores social action and ritual performance as motivations for economic change. In this article, 1 use both ethnographic and archaeological data to argue that ceremonial feasting and the need for socially valued goods, which are critical for ritual performance and necessary for a variety of social transactions, create the demand that underwrites and sustains economic intensification in small-scale societies. Food for large-scale feasts is acquired through the intensification of food production and procurement targeted specifically for feasting, rather than from the surplus available from routine subsistence production. Large-scale demands for socially valued goods tend to result in specialization on the production of "extraordinary" material culture, which is characterized by two modes of circulation, in networks of social obligations or as offerings in sacred locations. [Key words.craft specialization, exchange, feasting, ritual]     

Reservation food sharing among the Ache of Paraguay

We describe food transfer patterns among Ache Indians living on a permanent reservation. The social atmosphere at the reservation is characterized by a larger group size, a more predictable diet, and more privacy than the Ache typically experience in the forest while on temporary foraging treks. Although sharing patterns vary by resource type and package size, much of the food available at the reservation is given to members of just a few other families. We find significant positive correlations between amounts transferred among pairs of families, a measure of the "contingency" component required of reciprocal altruism models. These preferred sharing partners are usually close kin. We explore implications of these results in light of predictions from current sharing models. This research was supported by an L.S.B. Leakey Foundation grant and an NSF Graduate Fellowship to M. Gurven, and NSF Grant #9617692 to K. Hill and A. M. Hurtado. Michael Gurven recently obtained his Ph.D. from the University of New Mexico and is now an assistant professor at UC-Santa Barbara. His current interests include exploring ways in which socioecology influences variation in cooperation within and across human groups, and how cultural norms of fairness co-evolve with systems of resource production and distribution. Wesley Allen-Arave is pursuing his Ph.D. in anthropology at the University of New Mexico. His primary research interests focus on exploring variations across time and space in nonreciprocated altruistic acts, cooperation within social networks, and concerns over social approval. Kim Hill is a professor of anthropology in the Human Evolutionary Ecology (HEE) program at the University of New Mexico. His primary research interests include hunter-gatherer behavioral ecology, life history theory, food acquisition strategies, food sharing, cooperation, and biodiversity conservation in lowland South America. He has done fieldwork with Nahautl, Ache, Guarani, Hiwi, Mashco Piro, Matsiguenga, and Yora indigenous peoples of Central and South America. A. Magdalena Hurtado is associate professor of anthropology at the University of New Mexico. Her research interests include the evolution of cooperation between the sexes, infectious disease and immune system adaptations, the epidemiology of hunter-gatherer societies in transition, and the effects of health on economic productivity. During the past 20 years she has conducted fieldwork among several South American native populations but now works primarily among the Ache of eastern Paraguay.     

From "Rights" to "Ritual": AIDS Activism in South Africa

In this article, I investigate how the moral politics of HIV/AIDS activism in South Africa is contributing toward new forms of citizenship that are concerned with both rights-based struggles and with creating collectively shared meanings of the extreme experiences of illness and stigmatization of individual HIV/AIDS sufferers. I argue that it is precisely the extremity of the "near death" experiences of full-blown AIDS, and the profound stigma and "social death" associated with the later stages of the disease, that produce the conditions for HIV/AIDS survivors' commitment to "new life" and social activism. It is the activist mediation and retelling of these traumatic experiences that facilitates HIV/AIDS activist commitment and grassroots mobilization. It is also the profound negativity of stigma and social death that animates the activist's construction of a new positive HIV-positive identity and understanding of what it means to be a citizen–activist and member of a social movement.     

Afterword to "Anthropology and Human Rights in a New Key": The Social Life of Human Rights

In this article, I argue for an ethnographic approach to human rights that recognizes the plural and fragmentary nature of the international rights regime and the ideological promiscuity of rights talk. Instead of determining in advance the social or political character of rights, anthropologists could profitably draw from the insights of early-20th-century "legal realists" and look closely at the underlying assumptions and hidden practices of political and legal processes. Studying the "social life of human rights" would involve focusing on, inter alia, the performative dimensions of human rights, the dynamics of social mobilization, and the attitudinal changes of elite and nonelite social actors towards formulations of "rights" and "justice," both inside and outside the legal process. I conclude with a review of recent anthropological research on human rights epistemology and evaluate its implications for human rights policy.     

Art, Science, or Politics? The Crisis in Hunter-Gatherer Studies

In the complex history of hunter-gatherer studies, several overlapping and at times antagonistic discourses can be discerned. However, one critique has emerged that would render all hunter-gatherer discourses irrelevant and do away with the concept altogether. The paper explores the poststructuralist roots of this "revisionism" and then argues why the concept of hunter-gatherer continues to be politically relevant and empirically valid. However, if they are to fulfill their promise of illuminating an increasingly fragmented and alienating modernity, hunter-gatherer studies will have to become more attuned to issues of politics, history, context, and reflexivity.     

Biomechanical beam analysis of long bones from a late 18th century slave cemetery in Cape Town, South Africa

This study aims to quantify the physical demands of a sample of late 18th century skeletons from an unmarked burial site on Cobern Street, Cape Town, South Africa. Historical studies suggest that these individuals were either slaves or "free black" people of low socioeconomic standing. Cortical cross-sectional areas of paired humeri and tibiae from the Cobern Street collection (N = 29), a modern cadaver collection (N = 31), and a hunter-gatherer collection (N = 30) were compared by means of biomechanical beam analysis on computerized tomography scans. Results showed that the Cobern Street sample, both males and females, were closer to the modern group in total tibial cortical area and in the second moments and polar moments of cortical area, than to the hunter-gatherer group. It is assumed that these results can be explained by differences in lower limb activity. Tibial strength properties showed the hunter-gatherer peoples to be highly mobile and active walkers in comparison to the Cobern Street and modern samples. The males from the Cobern Street sample showed significantly higher values for humeral strength properties than either the hunter-gatherer or modern individuals, attesting to their status as manual laborers. The humeral cross-sectional strength properties for females were very similar between the Cobern Street and modern groups but again significantly different from the hunter-gatherer sample. The domestic chores performed by females of the recent cadaver sample may be very similar to those performed by the Cobern Street sample.     

Looking at the Camp: Paleolithic Depiction of a Hunter-Gatherer Campsite

Landscapes and features of the everyday world were scarcely represented in Paleolithic art, especially those features associated with the human landscape (huts and campsites). On the contrary, other figurative motifs (especially animals) and signs, traditionally linked to the magic or religious conceptions of these hunter-gatherer societies, are the predominant themes of Upper Paleolithic art. This paper seeks to present an engraved schist slab recently found in the Molí del Salt site (North-eastern Iberia) and dated at the end of the Upper Paleolithic, ca. 13,800 years ago. This slab displays seven semicircular motifs that may be interpreted as the representation of dome-shaped huts. The analysis of individual motifs and the composition, as well as the ethnographic and archeological contextualization, suggests that this engraving is a naturalistic depiction of a hunter-gatherer campsite. Campsites can be considered the first human landscape, the first area of land whose visible features were entirely constructed by humans. Given the social meaning of campsites in hunter-gatherer life-styles, this engraving may be considered one of the first representations of the domestic and social space of a human group.     

In the shadow of "death with dignity": medicine and cultural quandaries of the vegetative state

In this paper I address one site of technological development and cultural production, the permanent or persistent comatose condition and the institutions and practices that enable this life form to exist. As with other medical sites of ambiguity and change under recent scrutiny by anthropologists, the locations in which comatose bodies thrive are those in which the routinization of technology use in the clinic and a legitimating social and economic context come together to permit and create a further remapping of the notions of "life" and "person." I explore the new forms of knowledge, practice, and the body that are created at this site and how they are negotiated, and I discuss how the shifting understanding of "'culture" and "nature" both have an impact on and are informed by American quandaries about approaching death. I argue that beings who are neither fully alive, biologically dead, nor "naturally" self-regulating, yet who are sustained by modern medical practices, destabilize the existing social order in ways that are different from other hybrid forms, [medical anthropology, anthropology of the body, bioethics, personhood, culture/nature dichotomy]     

Hunting, social status and biological fitness

Hunting performance may be one of the most important routes to high prestige or social status among men in hunter-gatherer societies. Higher social status based on hunting performance has been linked to higher biological fitness outcomes almost everywhere this relationship has been investigated. This paper explores the proximate pathways underlying the positive correlation between hunting success and fitness, and discusses these in light of recent debates concerning the role of men in hunter-gatherer societies. Meat obtained from hunting directly provisions families and is also distributed to other group members, who may directly or indirectly pay back good hunters with meat, other food, services or favors. The display of hunting abilities may also increase men's fitness through extra-marital reproductive gains. We discuss prior results and provide a novel additional example using data collected among Tsimane horticultural-foragers of Bolivia. Despite the impression that most of the benefits that accrue to good hunters are in the form of extra-marital mating opportunities, we argue instead that most benefits may be gained within rather than outside marital unions.     

Parallel tool industries in New Caledonian crows

Individual specialization in the use of foraging tools occurs in hunter-gatherer societies but is absent in non-human primate tool use. 'Parallel tool industries' in hunter-gatherers are mainly based on strict sexual division of labour that is highly reliant on social conformity. Here, we show that 12 individuals in a population of New Caledonian crows on Maré Island had strong preferences for either stick tools or pandanus tools. Eight of the 12 crows had exclusive preferences. The individual specialization that we found is probably associated with different foraging niches. However, in spite of sexual size dimorphism there was no significant association between the sex of crows and their tool preferences. Our findings demonstrate that highly organized, strict sexual division of labour is not a necessary prerequisite for the evolution of parallel tool industries.     

A bioarcheological study of maxillary sinusitis

Maxillary sinusitis was studied as an indicator of poor air quality. Seven skeletal samples were examined from North America, England, and Nubia, and selected to represent different geographic locations, environments, and subsistence economies. Frequency rates varied from 17.2 to 51.5% of individuals affected with one or both sinuses preserved. Hardin Village had the highest frequency (51.5%), followed by the Aleuts (42.9%), "Illinois" (38.6%), Indian Knoll (38.5%), Kulubnarti (21.8%), Christchurch, Spitalfields (18.0%), and "South Dakota" (17.2%). Male frequencies ranged from 16.7 to 36.7%, but the female frequency ranged more widely from 18.0 to 76.5%. At most sites female rates exceeded male. The effect of urban and rural environment on sinusitis occurrence, and also subsistence economy, biological sex, and social status were explored, and comparative sites also considered; urban agricultural sites had a mean frequency of 48.5%, rural agricultural sites had a mean frequency of 45.0%, and hunter-gatherer sites had a mean frequency of 40.0%. In the urban sites male and female frequencies were near equal, but in the rural agricultural and hunter-gatherer sites female frequencies exceeded male frequencies. Dental disease was not found to have much impact on sinusitis frequency. The importance of the link between poor air quality and respiratory health is highlighted in clinical studies in both developed and developing countries, but also in bioarcheological studies.     

10,000 year history of plant use at Bosumpra Cave,Ghana

Investigations of hunter-gatherer subsistence, early food production, and the development of agroforestry systems during the Later Stone Age (LSA) of West Africa have proven challenging because of limited recovery and analysis of archaeological evidence relating directly to subsistence. This paper examines changes in the use of plant resources over a 10,000 year period at Bosumpra Cave, southern Ghana. Large quantities of recovered Canarium schweinfurthii (incense tree) and Elaeis guineensis (oil palm) endocarp preserved at the site allow for the assessment of previous observations about changes in the relative importance of tree fruit resources over time. Results point to the possibility that C. schweinfurthii was a managed resource and may be useful as a marker of forager subsistence in tropical forest regions. The exploitation of C. schweinfurthii persisted in the early and middle Holocene, but was eventually overshadowed in the late Holocene by Kintampo food-producing economies based on Pennisetum glaucum (pearl millet), Vigna unguiculata (cowpea) and E. guineensis. The Bosumpra deposits also yielded domesticated pearl millet and cowpea, allowing for the comparison of LSA hunter-gatherer and early food producer subsistence practices and cultural interactions in southern Ghana.     

The medicalization of "nature" in the "artificial body": surrogate motherhood in Israel

In this article, I draw on anthropological and feminist scholarship on the body and the nature/culture divide as a framework for understanding the place of surrogate mothers in a conceptual ideology that connects motherhood with nature. I explore links between the medicalization of childbirth in Israel and the personal agency of surrogate mothers as relayed through interviews. Taking the patriarchal context of the Israeli surrogacy law of 1996 into consideration, I underscore surrogates' imaginative use of medical metaphors as tools for the subversion of surrogacy's threatening social connotations. By redefining the surrogate body as "artificial" and locating "nature" in the commissioning mother's body, surrogates adopt medical rhetoric to transform surrogacy from a transgressive act into an alternative route toward achieving normative Israeli national reproductive goals.     

The Organization of Male and Female Labor in Foraging Societies: Implications for Early Paleoindian Archaeology

I use cross-cultural ethnographic data to explore the relationship between male and female subsistence labor among hunter-gatherer populations by examining data regarding resource procurement, time allocation, and task differentiation between the sexes relative to dependence on hunted foods. The findings indicate that female foragers generally perform a variety of nonsubsistence collection activities and preferentially procure high-return resources in hunting-based economies. I develop ideas about predictable relationships concerning the amount of time female foragers expend on subsistence and technological tasks relative to the dietary contribution of meat. I then use ethnographic trends to evaluate archaeological assumptions regarding the sexual division of labor in prehistoric foraging contexts, focusing on the dichotomous views of Clovis labor organization. I argue that archaeological interpretations of prehistoric labor roles in hunting-based foraging societies are commonly polarized between stereotypical views of male and female subsistence behaviors. I develop an interpretation of Early Paleoindian labor organization, emphasizing female labor in the production of material goods and the procurement of low-risk plant and animal resources based on global economic trends among foragers.