Geoff Childs

Tibetan Transitions: Historical and Contemporary Perspectives on Fertility, Family Planning, and Demographic Change

Tibetan Transitions uses the dual lenses of anthropology and demography to analyze population regulating mechanisms in traditional Tibetan societies, and to document recent transitions from high to low fertility throughout the Tibetan world. Using the authors case studies on historical Tibet, the Tibet Autonomous Region, the highlands of Nepal, and Tibetan exile communities in South Asia, this book provides a theoretical perspective on demographic processes by linking fertility transitions with family systems, economic strategies, gender equity, and family planning ideologies. Special attention is devoted to how institutions (governmental and religious) and the agency of individuals shape reproductive outcomes in both historical and contemporary Tibetan societies, and how demographic data has been interpreted and deployed in recent political debates.

Polyandry and population growth in a historical Tibetan society

Despite considerable speculation virtually nothing is known about the empirical relationship between traditional Tibetan administrative systems, household processes, and demographic trends in historical Tibetan populations because indigenous data sources have never been systematically analyzed. This article examines a 1958 tax register from Kyirong, formerly a district-level political division in southern Tibet, and demonstrates the significance of such archival sources for population research. Indirect demographic methods are used in conjunction with retrospective interviews to estimate levels of marriage and fertility in Kyirong, a society where polyandry was the normative form of marriage. By linking fertility and the rate of population growth with ethnographic data on household processes, the study provides both a qualitative and quantitative perspective on the practice of polyandry in a traditional Tibetan setting, and thereby critiques previous assumptions about population dynamics within historical Tibetan populations.

Depopulating the himalayan highlands: Education and outmigration from ethnically tibetan communities of Nepal

Abstract Communities that have thrived for centuries in Nepals rugged mountain environments are facing rapid population declines caused by the outmigration of youths, both males and females in nearly equal numbers, who are sent by parents to distant boarding schools and monasteries for secular and religious education. This paper documents the magnitude of outmigration, migration destinations, migrations impact on the age–sex composition of sending communities, the effect of migration on fertility, and projected trends of population decline and aging. The authors conclude by discussing potential long-term threats to the viability of ethnically Tibetan communities in the Himalayan highlands, including outmigrations effect on agricultural production, the family-based care system for the elderly, socioeconomic inequalities, and human capital.

Externally-Resident Daughters, Social Capital, and Support for the Elderly in Rural Tibet

This paper focuses on assistance that externally-resident daughters provide for their aging parents in rural Tibet, China, to challenge the notion that rapid modernization invariably threatens family-based care systems for the elderly. The authors discuss social and economic changes associated with modernization that have created new opportunities for parents to send daughters out of their natal households in ways that can benefit them in old age. By investing in a daughter’s education so she can secure salaried employment, or by helping a daughter establish a small business so she can earn an independent livelihood, the authors demonstrate how some externally-resident daughters represent a novel form of social capital that parents can draw on for social support. Daughters with income and freedom from extended family obligations are now providing elderly parents with (1) leverage against co-resident children who do not treat them well, (2) temporary places of refuge from ill-treatment at home, (3) caretaking services and financial support when they require hospitalization, and (4) financial resources independent of their household which they can use to pursue age-appropriate activities like pilgrimage. The authors conclude that this new form of social capital vested in externallyresident daughters is having a positive impact on the lives of the elderly in rural Tibet.

Milk at altitude: Human milk macronutrient composition in a high‐altitude adapted population of tibetans

OBJECTIVE The physiological challenges of high altitude have led to population-specific patterns of adaptation. These include alterations to child growth and reproduction, including lactation. However, while breastfeeding has been investigated, nothing is known about milk composition in high altitude adapted populations. MATERIALS AND METHODS Here, we investigate milk macronutrient composition, volume, and energy in a sample of 82 Tibetans living at high and low altitude in rural villages (Nubri Valley, Nepal) and at low altitude in Kathmandu, Nepal. Milk samples were collected in the morning using hand expression, frozen, and assayed for fat, protein, and total sugars. Reproductive histories and health recalls were also collected. RESULTS Milk fat averaged 5.2 ±2.0 g/100 mL, milk sugar 7.37 ± 0.49 g/100 mL, and milk protein 1.26 ± 0.35 g/100 mL for a mean energy density of 81.4 ± 17.4 kcal/100 mL. There were no associations between altitude of residence and milk composition; however, overall milk fat was high compared to reference populations. Within the three groups, milk fat was positively associated with infant age (B = 0.103; p < 0.001) and maternal triceps skinfold thickness (B = 0.095; p < 0.01) while milk sugar was significantly and inversely associated with maternal parity and triceps skinfold thickness. DISCUSSION Milk fat, and consequently milk energy, may be increased in high-altitude adapted Tibetans when compared to populations living at low altitude. The association between milk fat and maternal adiposity suggests that milk composition may be sensitive to maternal adiposity in this sample, likely reflecting increased metabolic costs of producing a high-fat milk.

Demographic analysis of small populations using the own-children method.

This article discusses the own-childrenmethod, a reverse-survival techniquedevised by demographers to estimate Total Fertility Rates in the absence of detailed data on reproduction. The method is useful for researchers such as anthropologists since the basic data requirements can be met through a household survey. It can help researchers answer key questions concerning population processes within well-delineated social, cultural, economic, and political contexts. The author uses a historical tax register from Tibet to illustrate the steps taken when using the own-children method.

Old-age security, religious celibacy, and aggregate fertility in a Tibetan population

Using the family system as a framework, this study investigates the connection between old-age security concerns and aggregate fertility in Sama and Lho, two ethnically Tibetan villages of highland Nepal. The microdemographic approach reveals a difference in family systems between the two villages that results in Sama having a significantly lower level of fertility than Lho. The key difference lies in the practice of Sama’s (but not Lho’s) householders of designating a daughter to be a nun, a strategy meant to retain female labour within the household and thereby guarantee a caretaker in old age. Although the effect of this practice on individual fertility is unclear, the comparison with Lho reveals how it sharply curtails aggregate fertility by preventing nearly one in five women from marrying. In this case the motivation to ensure old-age security acts as an unintentional preventive check on population growth. Comparisons with other societies illustrate how the population of Sama combines elements of both the historical European and Asian demographic experiences.

Dynamics of Indigenous demographic fluctuations: lessons from sixteenth-century Cusco, Peru

Reconstruction of the local impacts of imperial expansion is often hindered by insufficiently detailed indigenous demographic data. In the case of Spanish expansion in the Americas, native population declines are widely observed, but underlying dynamics are still incompletely understood. This paper uses a 1569 survey of more than 800 nontributary indigenous households in the Yucay Valley (highland Peru) to investigate demographic changes occurring during the Spanish transformation of the Inka imperial heartland. A suite of demographic analyses reveals that while the study population experienced significant demographic stresses, fertility rates recovered to levels that would lead to population growth in the long term. These new perspectives on indigenous fertility indicate that some rural Andean populations successfully adapted to new imperial arrangements. Long-term demographic declines in the Yucay Valley and surrounding region may thus be attributed to recurring disasters (especially epidemic disease) and an insatiable colonial administration that was not sufficiently flexible or sensitive to dynamics of demographic flux.

Ethnically Tibetan women in Nepal with low hemoglobin concentration have better reproductive outcomes

Elevated maternal hemoglobin concentration associated strongly with lower lifetime reproductive success among ethnically Tibetan women at 3000-4100m in Nepal. These findings are consistent with the hypothesis that unelevated hemoglobin concentration is an adaptation shaped by natural selection resulting in low hemoglobin levels among Tibetans compared with visitors and Andean highlanders.

A longitudinal cline characterizes the genetic structure of human populations in the Tibetan plateau

Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their demography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with worldwide genetic variation data. We found a clear signal of genetic stratification across the east-west axis within Tibetan samples. Samples from more eastern locations tend to have higher genetic affinity with lowland East Asians, which can be explained by more gene flow from lowland East Asia onto the plateau. Our findings corroborate a previous report of admixture signals in Tibetans, which were based on a subset of the samples analyzed here, but add evidence for isolation by distance in a broader geospatial context.