Native Amazonian Society Research Articles

Does the Future Affect the Present? The Effects of Future Weather on the Current Collection of Planted Crops and Wildlife in a Native Amazonian Society of Bolivia

Unlike neighboring disciplines, anthropology rarely studies how actual future events affect current behavior. Such studies could lay the groundwork for studies of ethno-forecasting. Psychologists argue that people forecast poorly, but some empirical work in cultural anthropology suggests that at least with weather, rural people might make reasonably accurate forecasts. Using data from a small-scale, pre-industrial rural society in the Bolivian Amazon, this study estimates the effects of future weather on the current collection of planted crops and wildlife. If actual future events affect current behavior, then this would suggest that people must forecast accurately. Longitudinal data covering 11 consecutive months (10/2002–8/2003, inclusive) from 311 women and 326 men ≥age 14 in 13 villages of a contemporary society of forager-farmers in Bolivia’s Amazon (Tsimane’) are used. Individual fixed-effect panel linear regressions are used to estimate the effect of future weather (mean hourly temperature and total daily rain) over the next 1–7 days from today on the probability of collecting wildlife (game, fish, and feral plants excluding firewood) and planted farm crops (annuals and perennials) today. Daily weather records come from a town next to the Tsimane’ territory and data on foraging and farming come from scans (behavioral spot observations) and surveys of study participants done during scans. Short-term future weather (≤3 days) affected the probability of collecting planted crops and wildlife today, although the effect was greater on the amount of planted crops harvested today than on the amount of wildlife collected today. Future weather beyond 3 days bore no significant association with the amount of planted crops harvested today nor with the amount of wildlife collected today. After controlling for future and past weather, today’s weather (mean hourly temperature, but not rain) affected the probability of collecting wildlife today, but today’s weather (temperature or rain) did not affect the probability of collecting planted crops today. The study supports prior work by anthropologists suggesting that rural people forecast accurately. If future weather affects the probability of harvesting planted crops and collecting wildlife today, then this suggests that Tsimane’ must forecast accurately. We discuss possible reasons for the finding. The study also supports growing evidence from rural areas of low-income nations that rural people tend to protect their food production and food consumption well against small idiosyncratic shocks or, in our case, against ordinary daily weather that is not extreme. However, the greater responsiveness of daily foraging output compared with daily farming output to today’s weather suggests that foraging might not protect food consumption as well as farming against adverse climate perturbations.

Moving beyond a Snapshot to Understand Changes in the Well‐Being of Native Amazonians

Forces such as the opening of trade, globalization, multinational corporate resource extraction, urbanization, acculturation, and colonization catalyze economic, ecological, and sociocultural change, which can threaten the well‐being and habitat of native Amazonians. Understanding these forces is of paramount importance to improve the well‐being of native Amazonians and to foster the conservation of biological diversity, yet most analyses of these forces rely on cross‐sectional data. Though adequate to describe the association between variables at one point in time, cross‐sectional data do not allow one to estimate changes in well‐being over time. We collected data annually during five consecutive years (2002–2006, inclusive) from a foraging and farming society of native Amazonians in Bolivia (Tsimane’) to estimate annual rates of change for seven indicators of adult well‐being. Indicators encompassed both objective and subjective measures of well‐being that included economic, health, psychological, and s...

Long-Term (Secular) Change of Ethnobotanical Knowledge of Useful Plants: Separating Cohort and Age Effects

Anthropologists, conservation biologists, and psychologists have generally found a long-term (secular) decline of ethnobotanical knowledge among indigenous people. To estimate such knowledge loss, researchers have typically relied on a single cross-sectional data set to (a) measure knowledge among people of different ages, (b) compare measures between ages, and (c) infer a loss of knowledge if the old knew more than the young. We improve on the approach by simultaneously controlling for cohort effects and age effects—the first refers to the effect of the birth period and the second refers to the effect of the life cycle (or aging). Failure to simultaneously control for both effects may produce the misleading impression that the old know more than the young, and the conclusion that the difference reflects a secular loss of knowledge when in fact it may reflect different positions in the life cycle. We use data collected during 2005 from a native Amazonian society of foragers-farmers in Bolivia (Tsimane') t...

The relation between forest clearance and household income among native Amazonians: Results from the Tsimane' Amazonian panel study, Bolivia

The Amazon rain forest harbors some of the world's richest biological diversity. During the twentieth century, two types of actors cleared that forest: native Amazonians and outside encroachers. Of the two actors, we know more about what drives outside encroachers to clear forest than about what drives native Amazonians to clear forest. The past research focus has served well because during the twentieth century outside encroachers cleared most of the Amazonian forest. But the past research focus needs to be expanded because native Amazonians are claiming de jure stewardship of the forests they inhabit, and with tighter jurisdiction over those forests will likely come changes in the amount of forest native Amazonians clear. Prior research in rural areas of low-income nations suggests that household income affects household forest clearance. To estimate the effects of household real income on the total forest area (old-growth + fallow) cleared by households we use a panel composed of five annual household surveys (2002–2006, inclusive) from 324 households of a native Amazonian society in Bolivia (Tsimane'). We control for household and village fixed effects and use an instrumental variable for household income. We find positive and significant household real income elasticities of forest clearance of 0.35 and 0.47 and an increase in forest clearance of 5.3%/year. The main finding stood up well to sensitivity analysis. These estimates suggest that in the near future, the forest in the Tsimane' territory will likely face increasing pressure from the Tsimane' themselves, not just from outside encroachers.

Ethnobotanical Knowledge and Crop Diversity in Swidden Fields: A Study in a Native Amazonian Society

Crop diversity protects food consumption in poor households within developing nations. Here we estimate the association between crop diversity on swidden fields and ethnobotanical knowledge. We conducted research among 215 male household heads from a native Amazonian society. Using multivariate regressions, we found higher crop diversity among households that depend on agricultural production for household consumption. We also found a statistically significant and positive, but low, association between the ethnobotanical knowledge of the male household head and crop diversity. Doubling the stock of ethnobotanical knowledge of the male household head is associated with a 9% increase in the number of crops sown by a household. The association remained after we controlled for the household level of market exposure, but vanished after we controlled for the social capital of the male household head. Future research should compare the association between ethnobotanical knowledge and crop diversity across different agricultural systems (i.e., home gardens, fallow fields).

Tsimane’ Amazonian Panel Study (TAPS): The first 5 years (2002–2006) of socioeconomic, demographic, and anthropometric data available to the public

The Tsimane’ Amazonian Panel Study (TAPS) is making available the first five years (2002–2006, inclusive) of annual socioeconomic, demographic, and anthropometric data available to the public. The information comes from a foraging-farming society of native Amazonians in Bolivia and includes 13 villages, 332 households, and 1985 people who have been tracked annually since 2002. The article provides a brief overview of the data covered and the steps needed to access the data.

Assortative mating and offspring well-being: theory and empirical findings from a native Amazonian society in Bolivia

Mate choice matters for inclusive fitness, household economic efficiency, assimilation, stratification, and economic inequalities in society. In positive assortative mating, people pair with someone who resembles them along a trait, whereas in negative assortative mating, people pair with someone who differs from them along a trait. In industrial nations, people tend to follow positive assortative mating for fundamental demographic dimensions (e.g., age, schooling) and might practice negative assortative mating for economic outcomes (e.g., earnings). Research on assortative mating has focused on industrial nations, generally compared only one trait between couples, and paid scant attention to the effects of assortative mating for offspring well-being. If assortative mating enhances inclusive fitness, it might also enhance offspring well-being. Drawing on data from a farming–foraging society in the Bolivian Amazon (Tsimane') that practices preferential cross-cousin marriage, we ( a) identify six parental traits (age, knowledge, wealth, schooling, height, and smiles) for which Tsimane' might practice assortative mating and ( b) test the hypothesis that assortative mating enhances offspring well-being. Proxies for offspring well-being include height and school attainment. Tsimane' resemble people of industrial nations in practicing mostly positive assortative mating. Pairwise, mother–father and Pearson correlations of age, schooling, and earnings among Tsimane' resemble correlations of industrial nations. Correlation coefficients for the six parental traits were far higher than correlations that might happened just by chance. We found weak support for the hypothesis that assortative mating improves offspring well-being.

Non-market Returns to Traditional Human Capital: Nutritional Status and Traditional Knowledge in a Native Amazonian Society

In industrial economies schooling produces positive non-market returns but do traditional forms of human capital also produce such returns, and do schooling and traditional human capital act as complements or substitutes in their association with well-being? Drawing on data from 450 adults (16+ years of age) from an indigenous Amazonian society in Bolivia, we estimate the association between traditional plant knowledge and nutritional status as measured by body-mass index. After conditioning for many covariates, we find that doubling an adult's traditional knowledge is associated with a mean improvement in BMI of 6.3 per cent; the association is stronger for unschooled adults and for those living far from the market town. Though schooling bore a negative association with traditional knowledge, those two forms of human capital had independent associations with BMI. The analysis suggests that schooling does not necessarily undermine the accumulation of traditional knowledge.

Can We Trust an Adult's Estimate of Parental School Attainment? Disentangling Social Desirability Bias and Random Measurement Error

Researchers often need to know the parental school attainment of adult subjects. When researchers cannot ask parents about their school attainment, they must ask adult offspring about the school attainment of their parents. We assess the accuracy of answers provided by adults about the school attainment of their parents with data from a native Amazonian society in Bolivia (Tsimane'). Offspring overestimate the school attainment of their parents. They also report inaccurately other human capital attributes of their parents (e.g., writing skills, fluency speaking Spanish, practical indigenous knowledge of medicinal plants). Results mesh with findings from the United States about the lack of reliability of adults' self-reports about parental school attainment and with prior research among the Tsimane' suggesting significant misreporting of other outcomes (e.g., age, income, parental height).

Rain, temperature, and child–adolescent height among Native Amazonians in Bolivia

Background: Global climate change and recent studies on early-life origins of well-being suggest that climate events early in life might affect health later in life.Aim: The study tested hypotheses about the association between the level and variability of rain and temperature early in life on the height of children and adolescents in a foraging–farming society of native Amazonians in Bolivia (Tsimane').Subject and methods: Measurements were taken for 525 children aged 2–12 and 218 adolescents aged 13–23 in 13 villages in 2005. Log of standing height was regressed on mean annual level and mean intra-annual monthly coefficient of variation (CV) of rain and mean annual level of temperature during gestation, birth year, and ages 2–4. Controls include age, quinquennium and season of birth, parent's attributes, and dummy variables for surveyors and villages.Results: Climate variables were only related with the height of boys age 2–12. The level and CV of rain during birth year and the CV of rain and level of temperature during ages 2–4 were associated with taller stature. There were no secular changes in temperature (1973–2005) or rain (1943–2005).Conclusion: The height of young females and males is well protected from climate events, but protection works less well for boys ages 2–12.

The effect of rainfall during gestation and early childhood on adult height in a foraging and horticultural society of the Bolivian Amazon

Recent research documents the effects of adverse conditions during gestation and early childhood on growth responses and health throughout life. Most research linking adverse conditions in early life with adult health comes from industrial nations. We know little about the plasticity of growth responses to environmental perturbations early in life among foragers and horticulturalists. Using 2005 data from 211 women and 215 men 20+ years of age from a foraging-horticultural society of native Amazonians in Bolivia (Tsimane'), we estimate the association between (a) adult height and (b) rainfall amount and variability during three stages in the life cycle: gestation (year 0), birth year (year 1), and years 2-5. We control for confounders such as height of the same-sex parent. Rainfall amount and variability during gestation and birth year bore weak associations with adult height, probably from the protective role of placental physiology and breastfeeding. However, rainfall variability during years 2-5 of life bore a negative association with adult female height. Among women, a 10% increase in the coefficient of variation of rainfall during years 2-5 was associated with 0.7-1.2% lower adult height (1.08-1.93 cm). Environmental perturbations that take place after the cessation of weaning seem to leave the strongest effect on adult height. We advance possible explanations for the absence of effects among males.

On the Measure of Income and the Economic Unimportance of Social Capital: Evidence from a Native Amazonian Society of Farmers and Foragers

Economists equate economic self-sufficiency (autarky) with low income and stress the economic role of social capital as a form of self-insurance in poor rural areas of developing nations. In contrast, anthropologists speak of the original affluence of foragers and see social capital as serving economic and social roles. Economists do not work with highly autarkic peoples such as part- or full-time foragers, and cultural anthropologists have not provided formal, comprehensive estimates of income or of the monetary value of social capital in highly autarkic societies. Drawing on data from 611 adults of 244 households in 13 villages of a highly autarkic society of swidden farmers, hunters, and gatherers in the Bolivian Amazon, the Tsimane', we present measures of personal income and of the monetary value of social capital. Daily personal income reaches US $2.35-3.52, which is above the international poverty line of US $1-2, on a par with the income in the rest of Bolivia, and three times higher than the in...

BMI, income, and social capital in a native Amazonian society: Interaction between relative and community variables

Researchers have shown interest in the relation between (a) social capital and individual income and (b) the individual health of people of industrial nations. The socioeconomic complexity of industrial nations makes it difficult to arrive at firm conclusions. We circumvent the obstacle by using data from a small-scale rural society of foragers-farmers in the Bolivian Amazon (Tsimane'). We examine the interactions between the outcome (BMI) and relative income, relative social capital, village income, and village social capital. We test three hypotheses: people in villages with more social capital should have higher BMI, the positive association between social capital and BMI will be more marked among the less well-off, and better-off people who display generosity will have higher BMI than better-off people who do not. On the methodological side we show the importance of: focusing on relative measures of income and social capital, estimating interaction between community and relative measures of income and social capital, and showing results through contour plots that summarize the relation between BMI and pairs of explanatory variables. On the substantive side we find evidence that village social capital and village income complement each other and are associated with higher BMI, the rich who are stingy have lower BMI than the rich who display generosity, and increase in village income might reduce individual incentives to invest in social capital. We explore interactions between explanatory variables and their influence on BMI, and end by recommending the use of an experimental research design to obtain unbiased estimates of causal effects.

The Role of Community and Individuals in the Formation of Social Capital

Because social capital shapes many desirable socioeconomic outcomes, we ask what incentives drive private investments in social capital. We estimate the association between private investments in social capital (outcome variable) and the following explanatory variables: (a) individual-level variables from an optimal investment model, (b) spillovers from group social capital, (c) village income inequality, and (d) market openness. We draw on information from Tsimane’, a native Amazonian society of foragers and farmers in Bolivia, and equate social capital with gifts, help given, and communal labor offered by the household. Age bore an inverted U-shaped and income bore a positive association with social capital, but geographic mobility, wealth, and schooling bore no significant association with social capital. We found strong group-level associations even after instrumenting social capital; the association probably stems from strong kinship ties which tend to blur the line between the group and the individual. Village measures of social capital were positively and significantly associated with private investments in social capital. We found some evidence that village income inequality and market openness were negatively associated with private investments in social capital.

How Well do Foragers Protect Food Consumption? Panel Evidence from a Native Amazonian Society in Bolivia

The ability of rural people to protect their food consumption matters because it captures their economic vulnerability. How well do foragers protect consumption from adverse income shocks and does protection work equally well for all people in the household? We answer the queries with data from 156 adults and 169 children collected over five consecutive quarters from the Tsimane', a native Amazonian society of foragers and farmers in Bolivia. We estimate whether quarterly changes in the logarithm of consumption bear an association with quarterly changes in the logarithm of cash income while controlling for many confounders, including covariant shocks. We use anthropometric indices of short-run nutritional status to proxy for food consumption and use instrumental variables to abate biases from the endogeneity of income. We found that child consumption was fully protected from income growth, but adult consumption was not as well protected. Estimates of income elasticities of consumption fell toward the lower range of estimates from previous studies of farming and industrial societies. We present several hypotheses to explain how the Tsimane' smooth consumption

Schooling's contribution to social capital: study from a native Amazonian society in Bolivia

Understanding why traditional cultures weaken matters because they embody humanity's heritage. Schooling has been singled out as an abrader of traditional culture. We assess whether schooling erodes one aspect of traditional culture: social capital as shown by generosity to people outside the household. In industrial nations researchers find positive associations between social capital and schooling. We hypothesize that in pre‐industrial societies schooling will produce ambiguous effects on social capital: it will reduce social capital expressed through labour help but increase social capital expressed through gifts given. Furthermore, we hypothesize that schooling will lower the likelihood of displaying social capital to kin. To test the hypotheses we use 2004 data from a highly autarkic society of farmers and foragers in the Bolivian Amazon, the Tsimane'. To strengthen the inferences we make about causality we use instrumental variables. Participants in the study included all people of 16+ years of age (n=574) in 13 villages. Social capital included (a) gifts given to people of other households and (b) labour help offered to people of other households and participation in communal work during the week before the day of the interview. Instrumental variables included childhood village of residence and father's writing ability. Contrary to expectations, schooling weakened all forms of social capital, including expressions of generosity toward kin, but results were statistically insignificant. Parameters estimated with standard techniques and with instrumental variables differed in sign and magnitude, suggesting that researchers should correct for the endogeneity of schooling when assessing schooling's effect on social capital. We end by discussing reasons for the weak statistical results.

Economic Development and Local Ecological Knowledge: A Deadlock? Quantitative Research from a Native Amazonian Society

Despite the growing interest in the topic, there has been little quantitative research about the causes and rate of acquisition and loss of local ecological knowledge. Some researchers have linked the loss of local ecological knowledge to the expansion of the market economy (Godoy et al., 1998; Ross, 2002; Reyes-Garcia et al., 2005a), others have found persistence in local ecological knowledge despite large socio-economic changes (Zarger and Stepp, 2004), and still others have found that integration into the market economy through an economic activity based in the natural environment could accelerate the acquisition of local ecological knowledge (Guest, 2002). The debate matters for policy-making because if integration to the market erodes local knowledge, there would be no possibility of simultaneously achieving conservation of local knowledge and economic development. In contrast, if integration to the market economy does not affect or does not always affect local knowledge, then some forms of market incorporation could develop without eroding local ecological knowledge. In this article we test how various forms of integration to the market economy affect local ecological knowledge. Local knowledge has many domains (i.e., myth, cosmology), including local ecological knowledge, which itself comprises many subdomains, such as plants, animals, insects, or soils. We proxy local ecological knowledge with ethnobotanical knowledge. We use a new way of measuring ethnobotanical knowledge that stresses skills that draw on ethnobotanical knowledge, and compare results with standard measures of ethnobotanical knowledge that stress passive knowledge. We hypothesize that only some forms of integration to the market economy, namely activities that take individuals out of their culture and environment, are associated with less local ecological knowledge. To explore the topic, we draw on information from 476 Tsimane’—a foraging-horticultural society in the Bolivian Amazon.

On the accuracy of perceived parental height in a native Amazonian society

Studies of secular trends in adult height in rural pre-literate societies are likely to show no change owing to random measurement error in age. In such societies, adults lack birth certificates and guess when estimating their age. We assess the accuracy of perceived height of the same-sex parent to estimate secular trends. We tested the method among the Tsimane’, a native Amazonian society of farmers and foragers in Bolivia. Subjects included 268 women and 287 men >20 years of age. Over half the sample reported inaccurately the height of their same-sex living parent, with a tendency to report no difference when, in fact, differences existed. Results highlight the pitfalls of using perceived parental height to examine secular trends in adult height among the Tsimane’, though the method might yield accurate information in other societies. We discuss possible reasons for the low accuracy of Tsimane’ estimates.

Signaling by consumption in a native Amazonian society

People signal status by producing, distributing, or consuming goods. Behavioral ecologists working with foragers stress signaling by production (e.g., supply of wildlife), whereas economists working in industrial economies stress signaling by individual consumption or expenditures. As foraging economies experience economic transformations, one expects greater reliance on individual consumption compared with production to signal status. We test two hypotheses: if people signal by individual consumption, they will allocate a higher share of their monetary expenditures to luxuries or to visible durable goods (Hypothesis 1) and the propensity to signal by individual consumption will be more salient among people closer to market towns (Hypothesis 2). To test the hypotheses, we draw on data from a native Amazonian society of foragers and slash-and-burn farmers in Bolivia (Tsimane') undergoing increasing exposure to the market economy. The sample included 161 women and 257 men 16+ years of age in 13 villages. The dependent variable was the share of total monetary expenditures allocated to different types of durable goods (e.g., clothing, luxuries, highly visible and less visible goods) during the previous year. Separate OLS regressions were used for women and men. We found support for Hypothesis 1. Higher levels of total monetary expenditures bore a positive association with the share of expenditures allocated to luxury goods and a negative association with expenditures allocated to less visible durable goods. Only among women did we find a positive association between total expenditures and the share of expenditures allocated to highly visible goods. We found no support for Hypothesis 2.

Babies, Bodies, and the Production of Personhood in North America and a Native Amazonian Society

Each society must determine how its youngest will come to achieve the status of persons, how they will be recognized and granted a place within a human community. This article examines the social processes involved in turning fetuses and infants into social beings in two societies: the United States and the Wari'1 (Pakaa Nova) Indians of Rondonia, Brazil. We are specifically concerned with how cultural models of the body are invoked in the social production of personhoods. Concepts of personhood are contingent on the social meanings given to bodies-newly forming babies' bodies in particular-and, in turn, on how body imageries are used to create and transform social relationships. The issue of how to define personhood is, of course, at the heart of some of today's most vexing social debates. In the United States, controversies over abortion, the use of fetal tissue, and life support for extremely premature infants reveal the beginning-of-life period to be one of deep moral ambiguity and uncertainty for the social collective. In all societies, the complexities and contradictions in normative ideologies of personhood are heightened during the