exchange, distribution, and consumption of goods. An influential collection of archaeological case stud- ies in the 1980s, edited by the processualists Colin Renfrew and John Cherry and published by Cambridge University Press, was entitled Ranking, Resource and Exchange – a tripartite summary of a whole social theory. Social complexity . Why do some societies become more differentiated internally than others – with more horizontal and vertical divisions? This emer- gence of social complexity is frequently, in history, associated with the state, involving class structures and disparities in the distribution of goods – wealth, monopolies of legal force, and violence, institutions such as organized religion, and manifestations in ma- terial culture such as the city. The main approach to such a question of social change is still an evolution- ary one. The idea is that the mechanisms of biological evolution offer a way of understanding social change such as the emergence of the state in the wake of agriculture. Do societies adapt to environments like biological species? Selective advantage is certain- ly a powerful principle that can govern the design of a social institution as well as an organism. We are here invoking the question of the bound- aries of the ‘human’ and the ‘social’. Much social archaeology since the 1960s has focused on social interactions with the natural environment – how a society feeds itself and uses material resources, local and distant, through trade and exchange, and how variability in environment may be a factor in social change. The tendency now is to discount simple causes and to blur a radical distinction between the natural and the human. Just as people are intimately associated with their goods, so too they are intimately connected with other species and the environment – through economic, religious, and communicative practices. Archaeologists, for example, are less in- clined now to explain agriculture through environ- mental factors or economic advantage, but rather locate farming within complex cultural ecologies, which have people thinking of other species in new ways in settled architectures that speak of new cos- mological understanding. See also: Engendered Archaeology; Evolutionary Ar- chaeology; Historical Materialist Approaches; Identity and Power; Individual, Archaeology of in Prehistory; Marxist Archaeology; Postprocessual Archaeology; Processual Archaeology; Social Inequality, Develop- ment of. Further Reading Preucel R and Meskell L (eds.) (2006) A Companion to Social Archaeology. Oxford: Blackwell. Shanks M and Tilley C (1987) Social Theory and Archaeology. Cambridge, UK: Polity. Trigger B (1990) A History of Archaeological Thought. Cambridge, UK: Cambridge University Press. SOCIAL VIOLENCE AND WAR Nam C Kim and Lawrence H Keeley, University of Illinois, Chicago, IL, USA ã 2008 Elsevier Inc. All rights reserved. Glossary ambush (or raid) A form of combat commonly employed in warfare among small-scale societies involving small groups of men sneaking into enemy territory to kill a few people. band A small, autonomous group of people made up of nuclear families that live together and are loosely associated with a territory. Often numbering as low as 20 or as high as a few hundred, bands are typically found amongst societies with foraging subsistence economies. bastion A projecting portion of a fortification barrier that allows flanking fire against attackers approaching the curtain. chiefdom Society headed by individuals with certain skills, authority, and power. Chiefdoms are associated with greater population density and are marked by signs of social ranking and stratification. Chiefdoms tend to be more complex and organized than smaller-scale societies such as tribes. curtain The outer or enclosing wall or barrier of a fortification. earthworks Types of fortifications constructed from large quantities of soil. palisade A fence of posts forming a defensive barrier or curtain. ramparts Fortification consisting of an embankment, often with a parapet built on top. siege Act or process of surrounding and attacking a fortified place in such a way as to isolate it from help and supplies. state An autonomous political unit, encompassing many communities within its territory and having a centralized government. The government usually has the power to collect taxes, draft men for work or war, and decree and enforce laws. Also, states represent a major departure from earlier kin-based societies and state leaders usually possess a monopoly over the use of deadly force. tribe Loosely defined as a large collection of bands, leadership tends to be based on charisma and skill with an absence of official or political offices containing real power. Kinship ties and family structures form the primary bonding mechanisms. SOCIAL VIOLENCE AND WAR 2053