Demographic anthropology

Demography is the study of population dynamics. The primary foci of demography are rates and levels of mortality, fertility, and migration and how these all interact to produce population growth (or decline), density, and ageand sex-structures; how these rates or levels vary across time and space and what produces such variation; and what consequences these have on other aspects of human (or nonhuman) existence. These demographic phenomena lie at the very heart of evolution. Natural selection occurs as a result of differential fertility and mortality within a population; gene flow occurs because of migration between populations; and the effects of genetic drift are dependent upon population size, which is an outcome of the interactions among mortality, fertility, and migration (Gage, DeWitte, & Wood, 2012). These demographic forces also affect, are affected by, and reflect many of the things that anthropologists find most interesting. For example, the age–sex structure of a population influences the population’s ratio of consumers to producers and numbers of potential marriage partners, and thus places limits on such things as subsistence strategies and household structure. The age–sex structure of a population can also significantly influence economic relationships among families and communities, as cultures often have inheritance and habitation rules that depend on the sex and sometimes age of individuals, and thus are inherently influenced strongly by demographic structure. Population growth and density affect socio-political structures and shape disease ecologies, which can, in turn, affect demographic rates and drive biological and cultural adaptations. Sociocultural phenomena also have the potential to powerfully shape demography. For example, warfare can have shortand long-term effects on sex ratios or age structures (as in the case of the post-World War II baby boom). Sexselective infanticide and abortion, and withholding of resources or medical care from daughters because of cultural preferences for sons affects sex ratios. Economic policies and warfare influence patterns of migration. Ultimately, demography is relevant to all fields of anthropology, whether or not all anthropologists are interested in demography itself and its effects on other aspects of human life. Although, as can be seen in the pages of the American Journal of Physical Anthropology, numerous anthropologists over the last 100 years of the journal’s existence have been explicitly interested in demography, and in demographic anthropology in particular. In contrast to national demography, which primarily focuses on large datasets (often derived from censuses) from European and other industrialized populations, demographic anthropology typically focuses on relatively small, nonindustrial populations from which data are collected as a part of ethnographic fieldwork. Demographic anthropology also examines the demography of populations in the past, as reconstructed from skeletal remains (paleodemography), historical documents (historical demography), or material culture and other evidence of human activities from archaeological sites (demographic archaeology). Demographic anthropology shares with the rest of anthropology a holistic approach, and seeks to understand demographic phenomena in the context of the specific sociocultural, environmental, economic, and political settings in which they exist. In demographic anthropology, the ultimate goal is not to simply describe the demographic characteristics of a living or past population. Rather, there is an explicit focus on the application of demographic data to address questions of an evolutionary, ecological, or cultural nature. In the first decades of the American Journal of Physical Anthropology, publications of a demographic nature were mostly limited to a handful of brief reports of demographic data from various populations, such as Hrdlička’s (1927) “Anthropology of the American Negro: Historical Notes,” and Field’s (1936) “Arabs of Iraq”. The first truly demographic anthropological studies (defined here by an attempt to address evolutionary, ecological, or cultural questions) published in AJPA did not appear until the 1930s, including Aberle’s (1931) study of fertility among Pueblo Indians. Aberle compared historical data from parish records to contemporary data collected via interviews in order to test assumptions about low fecundity among “primitive people” and the effects of “civilization” on birth rates. However, demographic anthropological publications remained relatively rare in the journal until the