Economic Theory Commons^™

Brain Volume, Energy Balance, And Cardiovascular Health In Two Nonindustrial South American Populations, Hillard Kaplan, Paul L. Hooper, Margaret Gatz, Wendy J. Mack, E. Meng Law, Helena C. Chui, M. Linda Sutherland, James D. Sutherland, Christopher J. Rowan, L. Samuel Wann, Adel H. Allam, Randall C. Thompson, David E. Michalik, Guido Lombardi, Michael I. Miyamoto, Daniel Eid Rodriguez, Juan Copajira Adrian, Raul Quispe Gutierrez, Bret A. Beheim, Daniel K. Cummings, Edmond Seabright, Sarah Alami, Angela R. Garcia, Kenneth Buetow, Gregory S. Thomas, Caleb E. Finch, Jonathan Stieglitz, Benjamin C. Trumble, Michael D. Gurven, Andrei Irimia

ESI Publications

Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-income nations. With a sample of 1,165 individuals aged 40 to 94, we analyze population differences in cross-sectional rates of decline in BV with age. We also assess the relationships of BV with energy biomarkers and arterial disease and compare them against findings in industrialized contexts. The analyses test three …

Natural Selection Of Immune And Metabolic Genes Associated With Health In Two Lowland Bolivian Populations, Amanda J. Lea, Angela Garcia, Jesusa Arevalo, Julien F. Ayroles, Kenneth Buetow, Steve W. Cole, Daniel Eid Rodriguez, Maguin Gutierrez, Heather M. Highland, Paul L. Hooper, Anne Justice, Thomas Kraft, Kari E. North, Jonathan Stieglitz, Hillard Kaplan, Benjamin C. Trumble, Michael Gurven

ESI Publications

A growing body of work has addressed human adaptations to diverse environments using genomic data, but few studies have connected putatively selected alleles to phenotypes, much less among underrepresented populations such as Amerindians. Studies of natural selection and genotype–phenotype relationships in underrepresented populations hold potential to uncover previously undescribed loci underlying evolutionarily and biomedically relevant traits. Here, we worked with the Tsimane and the Moseten, two Amerindian populations inhabiting the Bolivian lowlands. We focused most intensively on the Tsimane, because long-term anthropological work with this group has shown that they have a high burden of both macro and microparasites, as …

Catalysts And Impediments To Tax Increment Finance In Tulsa’S Historical African American Neighborhood, Bria A. Dixon

University of New Orleans Theses and Dissertations

This thesis assesses how Tulsa, Oklahoma grew to utilize tax increment financing (TIF) to produce economic activity in Tulsa’s historic downtown area. Specifically, how the creation, history, and maintenance of ONEOK Field, a $60 million, 6,000-seat sports venue in Tulsa’s historically African American neighborhood became the catalyst for Tulsa’s current TIF policy. In examining the fiscal outcomes of ONEOK Field, this thesis finds implications for inequitable investment in and around Tulsa’s Greenwood TIF district

Morocco’S Makhzen And The Challenge Of National Development, Zakaria Fatih

Journal of Global Initiatives: Policy, Pedagogy, Perspective

This article explores the question of national development in Morocco considering the institution of the makhzen. It asserts that to adequately assess Morocco’s national development as a post-colonial country, it is necessary to rely on an economic model based in politics rather than in theories exclusively informed by classical and neoclassical economics. Among the key economists called upon to investigate the validity of politics in discussions of national development and income inequality are the following: Simon Kuznets, Thomas Piketty, W. A. Lewis, and the duo Daron Acemoglu and James A. Robinson, all of whom continue a long tradition of economic …

Computed Tomography Shows High Fracture Prevalence Among Physically Active Forager-Horticulturalists With High Fertility, Jonathan Stieglitz, Benjamin C. Trumble, Horus Study Team, Caleb E. Finch, Dong Li, Matthew J. Budoff, Hillard Kaplan, Michael D. Gurven

ESI Publications

Modern humans have more fragile skeletons than other hominins, which may result from physical inactivity. Here, we test whether reproductive effort also compromises bone strength, by measuring using computed tomography thoracic vertebral bone mineral density (BMD) and fracture prevalence among physically active Tsimane forager-horticulturalists. Earlier onset of reproduction and shorter interbirth intervals are associated with reduced BMD for women. Tsimane BMD is lower versus Americans, but only for women, contrary to simple predictions relying on inactivity to explain skeletal fragility. Minimal BMD differences exist between Tsimane and American men, suggesting that systemic factors other than fertility (e.g. diet) do not …

The Dynamics Of Men's Cooperation And Social Status In A Small-Scale Society, Christopher Von Rueden, Daniel Redhead, Rick O'Gorman, Hillard Kaplan, Michael Gurven

ESI Publications

We propose that networks of cooperation and allocation of social status co-emerge in human groups. We substantiate this hypothesis with one of the first longitudinal studies of cooperation in a preindustrial society, spanning 8 years. Using longitudinal social network analysis of cooperation among men, we find large effects of kinship, reciprocity and transitivity in the nomination of cooperation partners over time. Independent of these effects, we show that (i) higher-status individuals gain more cooperation partners, and (ii) individuals gain status by cooperating with individuals of higher status than themselves. We posit that human hierarchies are more egalitarian relative to other …

A Fishy Problem: Effects Of Atlantic Salmon Farming In The Pacific Ocean, Madeleine A. Griffith

Student Theses 2015-Present

In this report, I explore the historical, climatological, economic, and ethical issues created by the contemporary industrial salmon farming practices off Pacific coast of the United States and Canada. Chapter 1 utilizes a variety of sources from Stephen Hume’s A Stain upon the Sea to Miller’s Living in the Environment, to examine the integral part salmon plays in both freshwater and marine ecosystems, the ecosystem services salmon contribute in wild and farmed settings, and the trends in salmon consumption around the world. Chapter 2 examines the historically relevant role salmon held among indigenous societies and how that role has changed …

Does Family Income Determine A Children Future Educational Attainment Level?, Diaisha T. Richards

Applied Economics Theses

Family income and education have been a major concern in a variety of researches, and as a topic in society. These two components are a major concern because they are known to be key elements in determining future success for an individual. Various studies investigated the significance, correlations and impacts these two factors have on one another. It is common for the amount of family income obtained to determine how much education one will receive in the future. This study focuses on testing the hypothesis that family income determines how much education a child will receive in the future. By …

The Legalization Of Street Vending In Los Angeles: Exploring The Impact On Vendors And Their Livelihoods, Karen Alpuche Caceres

Pomona Senior Theses

This thesis aims to unpack the impact the legalization of street vending and the subsequent regulation had on sidewalk vendors. Although legalization occurred state-wide through Senate Bill 946 in September of 2017, the rules and regulations for vending were passed at a city-level, and I am focusing on the City of Los Angeles specifically. Through interviews with government officials, non-profit partners and advocates, and vendors from different parts of the City, I analyze information around the policy itself, its history, and the impact it has and is expected to have on vendors and their businesses. While vendors have been central …

Variation Among Populations In The Immune Protein Composition Of Mother's Milk Reflects Subsistence Pattern, Laura D. Klein, Jincui Huang, Elizabeth A. Quinn, Melanie A. Martin, Alicia A. Breakey, Michael Gurven, Hillard Kaplan, Claudia Valeggia, Grazyna Jasienska, Brooke Scelza, Carlito B. Lebrilla, Katie Hinde

ESI Publications

Lay Summary: Adaptive immune proteins in mothers’ milk are more variable than innate immune proteins across populations and subsistence strategies. These results suggest that the immune defenses in milk are shaped by a mother’s environment throughout her life.

Background and objectives: Mother’s milk contains immune proteins that play critical roles in protecting the infant from infection and priming the infant’s developing immune system during early life. The composition of these molecules in milk, particularly the acquired immune proteins, is thought to reflect a mother’s immunological exposures throughout her life. In this study, we examine the composition of innate …

Marital Violence And Fertility In A Relatively Egalitarian High-Fertility Population, Jonathan Stieglitz, Benjamin C. Trumble, Hillard Kaplan, Michael Gurven

ESI Publications

Ultimate and proximate explanations of men’s physical intimate partner violence (IPV) against women have been proposed. An ultimate explanation posits that IPV is used to achieve a selfish fitness-relevant outcome, and predicts that IPV is associated with greater marital fertility. Proximate IPV explanations contain either complementary strategic components (for example, men’s desire for partner control), non-strategic components (for example, men’s self-regulatory failure), or both strategic and non-strategic components involving social learning. Consistent with an expectation from an ultimate IPV explanation, we find that IPV predicts greater marital fertility among Tsimané forager-horticulturalists of Bolivia (n = 133 marriages, 105 women). This …

Correction To: 'Greater Wealth Inequality, Less Polygyny: Rethinking The Polygyny Threshold Model', Cody T. Ross, Monique Borgerhoff Mulder, Seung-Yun Oh, Samuel Bowles, Bret Beheim, John Bunce, Mark Caudell, Gregory Clark, Heidi Colleran, Carmen Cortez, Patricia Draper, Russell D. Greaves, Michael Gurven, Thomas Headland, Janet Headland, Kim Hill, Barry Hewlett, Hillard Kaplan, Jeremy Koster, Karen Kramer, Frank Marlowe, Richard Mcelereath, David Nolin, Marsha Quinlan, Robert Quinlan, Caissa Revilla-Minaya, Brooke Scelza, Ryan Schacht, Mary Shenk, Ray Uehara, Eckart Voland, Kai Willführ, Bruce Winterhalder, John Ziker, Christopher Von Rueden

ESI Publications

No abstract provided.

Greater Wealth Inequality, Less Polygyny: Rethinking The Polygyny Threshold Model, Cody T. Ross, Monique Borgerhoff Mulder, Seung-Yun Oh, Samuel Bowles, Bret Beheim, John Bunce, Mark Caudell, Gregory Clark, Heidi Colleran, Carmen Cortez, Patricia Draper, Russell D. Greaves, Michael Gurven, Thomas Headland, Janet Headland, Kim Hill, Barry Hewlett, Hillard Kaplan, Jeremy Koster, Karen Kramer, Frank Marlowe, Richard Mcelreath, David Nolin, Marsha Quinlan, Robert Quinlan, Caissa Revilla-Minaya, Brooke Scelza, Ryan Schacht, Mary Shenk, Ray Uehara, Eckart Voland, Kai Willführ, Bruce Winterhalder, John Ziker, Christopher Von Rueden

ESI Publications

Monogamy appears to have become the predominant human mating system with the emergence of highly unequal agricultural populations that replaced relatively egalitarian horticultural populations, challenging the conventional idea—based on the polygyny threshold model—that polygyny should be positively associated with wealth inequality. To address this polygyny paradox, we generalize the standard polygyny threshold model to a mutual mate choice model predicting the fraction of women married polygynously. We then demonstrate two conditions that are jointly sufficient to make monogamy the predominant marriage form, even in highly unequal societies. We assess if these conditions are satisfied using individual-level data from 29 human …

A Martin Luther King Jr. Amendment To The U.S. Constitution: Toward The Abolition Of Poverty, Theodore Walker

Perkins Faculty Research and Special Events

Rev. Dr. Martin Luther King Jr. prescribed that we add an economic bill of rights to the U.S. Constitution. A King-Inspired bill of rights should include a constitutional amendment that enumerates a natural human right to be free from economic poverty, and appropriate enforcement legislation.

For the sake of abolishing slavery, the Thirteenth Amendment says:

(Section 1) Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.

(Section 2) Congress shall have power to enforce this article by …

Sex Differences In Political Leadership In An Egalitarian Society, Christopher Von Rueden, Sarah Alami, Hillard Kaplan, Michael Gurven

ESI Publications

We test the contribution of sex differences in physical formidability, education, and cooperation to the acquisition of political leadership in a small-scale society. Among forager-farmers from the Bolivian Amazon, we find that men are more likely to exercise different forms of political leadership, including verbal influence during community meetings, coordination of community projects, and dispute resolution. We show that these differences in leadership are not due to gender per se but are associated with men’s greater number of cooperation partners, greater access to schooling, and greater body size and physical strength. Men’s advantage in cooperation partner number is tied to …

Low Perceived Control Over Health Is Associated With Lower Treatment Uptake In A High Mortality Population Of Bolivian Forager-Farmers, Sarah Alami, Jonathan Stieglitz, Hillard Kaplan, Michael Gurven

ESI Publications

Indigenous people worldwide suffer from higher rates of morbidity and mortality than neighboring populations. In addition to having limited access to public health infrastructure, indigenous people may also have priorities and health perceptions that deter them from seeking adequate modern healthcare. Here we propose that living in a harsh and unpredictable environment reduces motivation to pursue deliberate, costly action to improve health outcomes. We assess whether variation in Health Locus of Control (HLC), a psychological construct designed to capture self-efficacy with respect to health, explains variation in treatment uptake behavior among Tsimane Amerindians (N=690; age range: 40–89 years; 55.8% female; …

Coronary Atherosclerosis In Indigenous South American Tsimane: A Cross-Sectional Cohort Study, Hillard Kaplan, Randall C. Thompson, Benjamin C. Trumble, L. Samuel Wann, Adel H. Allam, Bret Beheim, Bruno Frohlich, M. Linda Sutherland, James D. Sutherland, Jonathan Stieglitz, Daniel Eid Rodriguez, David E. Michalik, Chris J. Rowan, Guido P. Lombardi, Ram Bedi, Angela R. Garcia, James K. Min, Jagat Narula, Caleb E. Finch, Michael Gurven, Gregory S. Thomas

ESI Publications

Background—Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden.

Methods—We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with …

The Tsimane Health And Life History Project: Integrating Anthropology And Biomedicine, Michael Gurven, Jonathan Stieglitz, Benjamin C. Trumble, Aaron D. Blackwell, Bret Beheim, Helen Davis, Hillard Kaplan, Paul L. Hooper

ESI Publications

The Tsimane Health and Life History Project, an integrated bio-behavioral study of the human life course, is designed to test competing hypotheses of human life-history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a highfertility, kin-based context lacking amenities of modern urban life (e.g. sanitation, banks, electricity). Another aim is to understand how a high pathogen burden influences health and well-being during development and adulthood. A third aim addresses how modernization shapes human life histories and sociality. Here we outline the project’s goals, history, and main findings since its inception in 2002. …

Horticultural Activity Predicts Later Localized Limb Status In A Contemporary Pre-Industrial Population, Jonathan Stieglitz, Benjamin C. Trumble, Hillard Kaplan, Michael Gurven

ESI Publications

Objectives—Modern humans may have gracile skeletons due to low physical activity levels and mechanical loading. Tests using prehistoric skeletons are limited by the inability to assess behaviour directly, while modern industrialized societies possess few socio-ecological features typical of human evolutionary history. Among Tsimane forager-horticulturalists, we test whether greater activity levels and, thus, increased loading earlier in life are associated with greater later-life bone status and diminished age-related bone loss.

Materials and Methods—We used quantitative ultrasonography to assess radial and tibial status among adults aged 20+ years (mean±SD age=49±15; 52% female). We conducted systematic behavioural observations to assess earlier-life …

Master's Tools And The Master's House: A Historical Analysis Exploring The Myth Of Educating For Democracy In The United States, Timothy Scott

Doctoral Dissertations

Over the past forty-years, neoliberal education reform policies in the U.S. have spurred significant resistance, often galvanized by claims that such policies undermine public education as a vital institution of U.S. democracy. Within this narrative, many activists call to “save our schools” and return them to a time when public schools served the common good. With these narratives in mind, I explore the foundational and persistent power structures that characterize the U.S. as a means to reveal the fundamental purpose of its public education system. The questions that guide my research include: (1) With an understanding that capitalism, white supremacy, …

Human Grooming In Comparative Perspective: People In Six Small-Scale Societies Groom Less But Socialize Just As Much As Expected For A Typical Primate, Adrian V. Jaeggi, Karen Kramer, Raymond Hames, Evan J. Kiely, Cristina Gomes, Hillard Kaplan, Michael Gurven

ESI Publications

Objectives—Grooming has important utilitarian and social functions in primates but little is known about grooming and its functional analogues in traditional human societies. We compare human grooming to typical primate patterns to test its hygienic and social functions.

Materials and Methods—Bayesian phylogenetic analyses were used to derive expected human grooming time given the potential associations between grooming, group size, body size, terrestriality, and several climatic variables across 69 primate species. This was compared against observed times dedicated to grooming, other hygienic behavior and conversation among the Maya, Pumé, Sanöma, Tsimane’, Yanomamö, and Ye’kwana (mean number of behavioral scans …

Cognitive Performance Across The Life Course Of Bolivian Forager-Farmers With Limited Schooling, Michael Gurven, Eric Fuerstenberg, Benjamin C. Trumble, Jonathan Stieglitz, Bret Beheim, Helen Davis, Hillard Kaplan

ESI Publications

Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g. “effortful processing” abilities including fluid reasoning, and processing speed) improve throughout early adolescence and start declining in early adulthood, while other abilities (e.g. “crystallized” abilities like vocabulary breadth) improve throughout adult life, remaining robust even at late ages. Although schooling may impact performance and cognitive “reserve”, it has been argued that these age patterns of cognitive performance are human universals. Here we examine age patterns of cognitive performance among Tsimane forager-horticulturalists of Bolivia, and test whether schooling is related to differences in cognitive performance …

Growth References For Tsimane Forager-Horticulturalists Of The Bolivian Amazon, Aaron D. Blackwell, Samuel S. Urlacher, Bret Beheim, Christopher Von Rueden, Adrian V. Jaeggi, Jonathan Stieglitz, Benjamin C. Trumble, Michael Gurven, Hillard Kaplan

ESI Publications

Objectives—Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists.

Methods—Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0–29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for …

Salivary Microbiomes Of Indigenous Tsimane Mothers And Infants Are Distinct Despite Frequent Premastication, Cliff S. Han, Melanie Ann Martin, Armand E.K. Dichosa, Ashlynn R. Daughton, Seth Frietze, Hillard Kaplan, Michael D. Gurven, Joe Alcock

ESI Publications

Background. Premastication, the transfer of pre-chewed food, is a common infant and young child feeding practice among the Tsimane, forager-horticulturalists living in the Bolivian Amazon. Research conducted primarily with Western populations has shown that infants harbor distinct oral microbiota from their mothers. Premastication, which is less common in these populations, may influence the colonization and maturation of infant oral microbiota, including via transmission of oral pathogens. We collected premasticated food and saliva samples from Tsimane mothers and infants (9-24 months of age) to test for evidence of bacterial transmission in premasticated foods and overlap in maternal and infant salivary …

Conflict Or Congruence? Maternal And Infant-Centric Factors Associated With Shorter Exclusive Breastfeeding Durations Among The Tsimane, Melanie A. Martin, Geni Garcia, Hillard Kaplan, Michael Gurven

ESI Publications

No abstract provided.

Cardiovascular Disease And Type 2 Diabetes In Evolutionary Perspective: A Critical Role For Helminths?, Michael D. Gurven, Benjamin C. Trumble, Jonathan Stieglitz, Aaron D. Blackwell, David E. Michalik, Caleb E. Finch, Hillard Kaplan

ESI Publications

Heart disease and type 2 diabetes are commonly believed to be rare among contemporary subsistencelevel human populations, and by extension prehistoric populations. Although some caveats remain, evidence shows these diseases to be unusual among well-studied hunter-gatherers and other subsistence populations with minimal access to healthcare. Here we expand on a relatively new proposal for why these and other populations may not show major signs of these diseases. Chronic infections, especially helminths, may offer protection against heart disease and diabetes through direct and indirect pathways. As part of a strategy to insure their own survival and reproduction, helminths exert multiple cardio-protective …

An Epigenetic Clock Analysis Of Race/Ethnicity, Sex, And Coronary Heart Disease, Steve Horvath, Michael Gurven, Morgan E. Levine, Benjamin C. Trumble, Hillard Kaplan, Hooman Allayee, Beate R. Ritz, Brian Chen, Ake T. Lu, Tammy M. Rickabaugh, Beth D. Jamieson, Dianjianyi Sun, Shengxu Li, Wei Chen, Lluis Quintana-Murci, Maud Fagny, Michael S. Kobor, Philip S. Tsao, Alexander P. Reiner, Kerstin L. Edlefsen, Devin Absher, Themistocles L. Assimes

ESI Publications

Background: Epigenetic biomarkers of aging (the “epigenetic clock”) have the potential to address puzzling findings surrounding mortality rates and incidence of cardio-metabolic disease such as: (1) women consistently exhibiting lower mortality than men despite having higher levels of morbidity; (2) racial/ethnic groups having different mortality rates even after adjusting for socioeconomic differences; (3) the black/white mortality cross-over effect in late adulthood; and (4) Hispanics in the United States having a longer life expectancy than Caucasians despite having a higher burden of traditional cardio-metabolic risk factors.

Results: We analyzed blood, saliva, and brain samples from seven different racial/ethnic groups. …

Associations Between Male Testosterone And Immune Function In A Pathogenically Stressed Forager-Horticultural Population, Benjamin C. Trumble, Aaron D. Blackwell, Jonathan Stieglitz, Melissa Emery Thompson, Ivan Maldonado Suarez, Hillard Kaplan, Michael Gurven

ESI Publications

Objectives—Despite well-known fitness advantages to males who produce and maintain high endogenous testosterone levels, such phenotypes may be costly if testosterone-mediated investment in reproductive effort trade-off against investment in somatic maintenance. Previous studies of androgen-mediated trade-offs in human immune function find mixed results, in part because most studies either focus on a few indicators of immunity, are confounded by phenotypic correlation, or are observational. Here the association between male endogenous testosterone and 13 circulating cytokines are examined before and after ex vivo antigen stimulation with phytohaemagglutinin (PHA) and lipopolysaccharides (LPS) in a high pathogen population of Bolivian forager-horticulturalists.

Materials …

Health Costs Of Reproduction Are Minimal Despite High Fertility, Mortality And Subsistence Lifestyle, Michael Gurven, Megan Costa, Ben Trumble, Jonathan Stieglitz, Bret Beheim, Daniel Eid Rodriguez, Paul L. Hooper, Hillard Kaplan

ESI Publications

Women exhibit greater morbidity than men despite higher life expectancy. An evolutionary life history framework predicts that energy invested in reproduction trades-off against investments in maintenance and survival. Direct costs of reproduction may therefore contribute to higher morbidity, especially for women given their greater direct energetic contributions to reproduction. We explore multiple indicators of somatic condition among Tsimane forager-horticulturalist women (Total Fertility Rate = 9.1; n = 592 aged 15–44 years, n = 277 aged 45+). We test whether cumulative live births and the pace of reproduction are associated with nutritional status and immune function using longitudinal data spanning 10 …

High Resting Metabolic Rate Among Amazonian Forager-Horticulturalists Experiencing High Pathogen Burden, Michael Gurven, Benjamin C. Trumble, Jonathan Stieglitz, Gandhi Yetish, Daniel Cummings, Aaron D. Blackwell, Bret Beheim, Hillard Kaplan, Herman Pontzer

ESI Publications

Objectives—Resting metabolic rate (RMR) reflects energetic costs of homeostasis and accounts for 60-75% of total energy expenditure (TEE). Lean mass and physical activity account for much RMR variability, but the impact of prolonged immune activation from infection on human RMR is unclear in naturalistic settings. We evaluate the effects of infection on mass-corrected RMR among Bolivian forager-horticulturalists, and assess whether RMR declines more slowly with age than in hygienic sedentary populations, as might be expected if older adults experience high pathogen burden.

Materials and Methods—RMR was measured by indirect calorimetry (Fitmate MED, Cosmed) in 1,300 adults aged 20-90 …