Stephen Shennan

Bio: Stephen Shennan is an academic researcher from University College London. The author has contributed to research in topics: Population & Prehistory. The author has an hindex of 52, co-authored 192 publications receiving 10207 citations. Previous affiliations of Stephen Shennan include Massachusetts Institute of Technology & Arts and Humanities Research Council.

Comparative Anthropology and Human Inequality

Abstract: This is an outstanding set of papers that reasserts the importance of one of anthropology’s long-standing goals—the comparative evolutionary study of societies. The issue that it addresses, the factors affecting the emergence of economic inequality, could not be more significant. Making comparisons involves collecting comparable data from different societies, and the systematic collection of consistent comparative quantitative information that provides the basis for these papers represents a major achievement of lasting value. Asking new questions almost always involves the collection of inform ation that earlier scholars had not deemed important, but it is still difficult not to be disappointed that after 100 years of anthropological fieldwork, the number of cases from which the authors have been able to extract the data they need is very limited. A particular conceptual advance the authors make, central to their comparative approach, is their characterization of what might at first seem very disparate phenomena—acquisition of skills, numbers of exchange partners, and sizes of cattle herds, for example—as different forms of wealth (embodied, relational, and material), making use of the ideas of human capital and parental investment from economics and behavioral ecology. They also cleverly get around the issue of the multiple institutions and practices through which intergenerational resource transfers are affected by measuring outcomes, the degree to which parent and child values are correlated. This theoretically justified creative abstraction in defining appropriate variables is matched by the extremely powerful and sophisticated analytical methods used to obtain the many interesting results that provide the basis for the papers’ conclusions. Not least of these results is their demonstration of the inherited inequalities that exist in apparently egalitarian hunter-gatherer societies and that have a major impact on individuals’ life chances through the generations. Indeed, one conclusion that could be drawn from these results is that the claimed egalitarianism of many if not most huntergatherer societies is less a result of an evolved human psychology of “reverse dominance” (Boehm 1993) and more one of ecological conditions relating to the nature of resources. The idea that the key to the development of major inequalities in human societies might be the nature of what counts as wealth and the extent to which it is transmitted— and, specifically, the emergence of material wealth and its inheritance—is not new in itself. It is there in the property rights discussions of the “new institutional economics” and in Bowles’s (2004, chap. 11) earlier work, as well as in the discussions of Rogers (1995) and in Hayden’s (1997; Hayden, Bakewell, and Gargett 1996; see also Shennan 2002, chap. 8) studies, as the authors note. Moreover, the foundation of the explanation advanced here for the importance of material resources, especially land but also animals—that when they are in short supply, their predictability and excludability give lasting, reliable benefits that justify paying the costs of investing in improvements and of defending them and excluding others—goes back some time, not least to the early work of author Eric Smith (Dyson-Hudson and Smith 1978). What is new is the systematic demonstration of the high rates of transmission of material wealth and the higher levels of inequality associated with it compared with other wealth forms. It follows from this quite naturally, as the authors indicate, that the key to the growth of inequality in the Holocene is the greatly increased potential offered by certain forms of agriculture for more or less unlimited inequality arising from the inheritance of material resources, because of the great potential that they create for the rich to get richer over the generations, in comparison with the more limited and less reliable possibilities offered by embodied and relational wealth. On this basis, their attack on the often-made claim that the key to the inequality generated by agriculture is the possibility of surplus generation is entirely convincing; rather, surplus generation is a by-product of the differential accu-

Specialization, Exchange and Complex Societies. Edited by Elizabeth M. Brumfield and Timothy K. Earle. 27·5 × 22 cm. Pp. vii + 150, 35 figs. Cambridge: Cambridge University Press, 1987. ISBN 0-521-32118-2. £25.

Abstract: invites a closer look at domestication in the light of James Mellaart's work at Catal Hiiyuk and Hacilar. He does so on the correct assumption that domestication affected human communities as profoundly as their animals and plants. In parenthesis one cannot help wondering why this author sets such special store by 'contextual' archaeology. Isn't this something most of us have been trying to practise for the last half century or more? It is puzzling to know why the Institute's Reader in Human Biology should have chosen to expose some of the sentiments he airs in this volume. After all he specializes in the study of a Primate which has made itself human by pursuing excellence. Furthermore he works alongside colleagues engaged in tracing how in the course of millennia men have created diverse civilizations as an outcome of sustained elitism and the unrelenting pursuit of excellence. In their joint contribution Warwick Bray and Ian Glover between them advertise their anxieties over the pursuit of archaeological research in Third World countries. Happily neither of them has carried his scruples to their logical conclusion. I say happily advisedly because both of them have operated with exemplary tact and sensitivity while exploring the archaeology of their respective zones. Moreover they work in an Institute that can rightly take pride in having equipped field workers from thirty countries or more, mostly in the so-called Third World. It has done so to help them reveal more fully the histories of their own distinctive cultures. As the final section in this volume shows, by means of a map and gazetteer, pupils and staff of the London Institute have helped to elucidate the archaeology of many parts of the world.

The Web of Human Sexual Contacts

Abstract: Many ``real-world'' networks are clearly defined while most ``social'' networks are to some extent subjective. Indeed, the accuracy of empirically-determined social networks is a question of some concern because individuals may have distinct perceptions of what constitutes a social link. One unambiguous type of connection is sexual contact. Here we analyze data on the sexual behavior of a random sample of individuals, and find that the cumulative distributions of the number of sexual partners during the twelve months prior to the survey decays as a power law with similar exponents $\alpha \approx 2.4$ for females and males. The scale-free nature of the web of human sexual contacts suggests that strategic interventions aimed at preventing the spread of sexually-transmitted diseases may be the most efficient approach.

Massive migration from the steppe was a source for Indo-European languages in Europe

Abstract: We generated genome-wide data from 69 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of almost 400,000 polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of Western and Far Eastern Europe followed opposite trajectories between 8,000-5,000 years ago. At the beginning of the Neolithic period in Europe, ∼8,000-7,000 years ago, closely related groups of early farmers appeared in Germany, Hungary and Spain, different from indigenous hunter-gatherers, whereas Russia was inhabited by a distinctive population of hunter-gatherers with high affinity to a ∼24,000-year-old Siberian. By ∼6,000-5,000 years ago, farmers throughout much of Europe had more hunter-gatherer ancestry than their predecessors, but in Russia, the Yamnaya steppe herders of this time were descended not only from the preceding eastern European hunter-gatherers, but also from a population of Near Eastern ancestry. Western and Eastern Europe came into contact ∼4,500 years ago, as the Late Neolithic Corded Ware people from Germany traced ∼75% of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least ∼3,000 years ago, and is ubiquitous in present-day Europeans. These results provide support for a steppe origin of at least some of the Indo-European languages of Europe.

A cross-cultural analysis of the behavior of women and men: implications for the origins of sex differences.

Abstract: This article evaluates theories of the origins of sex differences in human behavior. It reviews the cross-cultural evidence on the behavior of women and men in nonindustrial societies, especially the activities that contribute to the sex-typed division of labor and patriarchy. To explain the cross-cultural findings, the authors consider social constructionism, evolutionary psychology, and their own biosocial theory. Supporting the biosocial analysis, sex differences derive from the interaction between the physical specialization of the sexes, especially female reproductive capacity, and the economic and social structural aspects of societies. This biosocial approach treats the psychological attributes of women and men as emergent given the evolved characteristics of the sexes, their developmental experiences, and their situated activity in society.