Archaeology is fundamentally a historical science, one that encompasses the general objectives of reconstructing, interpreting, and understanding past human societies. Isaiah Berlin’s perceptive comments on the inherent difficulties in practicing “scientific history” are particularly apropos for archaeology. Practitioners of archaeology find themselves allied (often simultaneously) with practitioners of the natural sciences, social sciences, and humanities in the project of writing history. In the United States archaeology developed within the discipline of anthropology as a social science, contributing an explicitly historical dimension to anthropological inquiry. In Europe archaeology is more closely allied with humanistic pursuits such as classics, philology, and art history. In the last decades of the 20th century, this marked distinction in archaeological training and scholarship began to blur as the practice of archaeology became increasingly global and continual communication among archaeologists across national and regional borders accelerated.

Archaeologists deploy the analytic techniques of many scientific disciplines—botany, chemistry, computer science, ecology, evolutionary biology, genetics, geology, and statistics, among others—to recover and interpret the material remains of past human activities. But, like historians, archaeologists attempt to reconstruct the events and processes that shaped and transformed past societies, and, wherever possible, to understand how those events and processes were perceived and affected by humans. Achieving this understanding requires ideas about how individuals and societies are formed and how they interact, ideas that archaeologists have frequently drawn from humanistic and social science disciplines such as philosophy, psychology, sociology, and cultural anthropology. In this sense, archaeology is a uniquely hybrid intellectual endeavour that requires knowledge of an eclectic, wide-ranging set of analytic methods and social theories to write the history of past societies.

Archaeology differs from the study of history principally in the source of the information used to reconstruct and interpret the past. Historians concentrate specifically on the evidence of written texts, while archaeologists directly examine all aspects of a society’s material culture—its architecture, art, and artifacts, including texts—the material objects made, used, and discarded by human beings. As a result, archaeology, unlike history, takes as its subject all past human societies, whether these were preliterate (prehistoric), nonliterate, or literate. Knowledge of prehistoric societies is exclusively the domain of archaeology and the allied natural sciences that, in the absence of written records, can generate information about the environmental and cultural contexts of ancient societies. Reconstructing the material world of past societies as fully as possible is the proximate goal of archaeology; interpreting the historical significance and cultural meaning of that material world is archaeology’s ultimate objective.

In order to systematically document and interpret the material remains of past societies, archaeologists have developed a common set of methods and procedures. These include archaeological survey (reconnaissance), excavation, and detailed analysis of recovered artifacts. Survey, or the discovery and recording of archaeological sites or other human-created features, such as roads and irrigation systems, is usually the first phase of archaeological research. Archaeological survey often employs aerial photographs and satellite images to locate human settlements and related features visible on the surface. Since the late 20th century, technologies of remote sensing, such as ground-penetrating radar, have extended archaeologists’ capacity to detect subsurface features. Subsequent ground reconnaissance is designed to map and describe archaeological sites. It frequently involves the systematic collection of surface artifacts (such as pottery, stone tools, human and animal bones, metal, and other durable objects) that can reveal the chronological placement (dating), spatial relationships, and, often, the social functions of archaeological sites.

After a thorough archaeological reconnaissance that documents the environmental context and spatio-temporal relationships of settlements and other human-created features, archaeologists embark on programs of excavation to discover and document a site’s material culture and the manner in which this material culture changed over time. The design and execution of an archaeological excavation is a highly technical dimension of the archaeologist’s craft that frequently requires engagement of an interdisciplinary team of scientists and technicians: surveyors, epigraphists, geologists, botanists, physical anthropologists, zoologists, and other specialists. The documentary record of an excavation includes detailed maps and architectural plans of excavated structures and other features, along with large quantities of recovered artifacts, the stratigraphic locations (that is, the precise horizontal and vertical position within the buried layers of a site) and depositional context of which have been meticulously recorded in standardized data forms.

The final procedure of documenting the material remains of past societies entails careful, and often technically specialized, quantitative and qualitative analysis of recovered artifacts. This systematic description and classification of objects by their chronological placement, material, form, process of production, use-life, and pattern of deposition depends upon a host of sophisticated analytic techniques developed to decode the history of these discarded objects, which once held social significance to the human communities in which they were made, used, and valued. Principal among these analytic techniques are various kinds of physical and chemical dating methods, including, most prominently, radiocarbon dating, which was developed in the 1940s by Nobel laureate Willard Libby at the University of Chicago.

Once the empirical evidence of past societies has been generated, archaeologists must make meaningful historical and cultural interpretations of that evidence. Archaeological evidence is most often a reflection of long-term history (interpretable mostly in decadal, generational, or even longer timescales). This means that, absent contemporaneous historical and textual evidence, archaeological interpretations are often restricted to the exploration of deeply embedded, perduring sociocultural structures and long-term sociohistorical change rather than to specific events and individual actions. As a result, archaeological interpretations rarely reach to an explanation of what events and processes meant in social or psychological terms to human actors. Nevertheless, archaeology, as a form of historical anthropology, offers keen insight into the human condition.

Physical anthropology

Physical anthropology is concerned with the origin, evolution, and diversity of people. Physical anthropologists work broadly on three major sets of problems: human and nonhuman primate evolution, human variation and its significance, and the biological bases of human behaviour. The course that human evolution has taken and the processes that have brought it about are of equal concern. In order to explain the diversity within and between human populations, physical anthropologists must study past populations of fossil hominins as well as the nonhuman primates. Much light has been thrown upon the relation to other primates and upon the nature of the transformation to human anatomy and behaviour in the course of evolution from early hominins to modern people—a span of at least four million years.

The processes responsible for the differentiation of people into geographic populations and for the overall unity of Homo sapiens include natural selection, mutation, genetic drift, migration, and genetic recombination. Objective methods of isolating various kinds of traits and dealing mathematically with their frequencies, as well as their functional or phylogenetic significance, make it possible to understand the composition of human populations and to formulate hypotheses concerning their future. The genetic and anthropometric information that physical anthropologists collect provides facts about not only the groups who inhabit the globe but also the individuals who compose those groups. Estimates of the probabilities that children will inherit certain genes can help to counsel families about some medical conditions.