Other Economics Commons^™

Sleep Restriction Alters The Integration Of Multiple Information Sources In Probabilistic Decision-Making, Jeryl Y. L. Lim, Johanna M. Boardman, Clare Anderson, David L. Dickinson, Daniel Bennett, Sean P. A. Drummond

ESI Publications

The detrimental effects of sleep loss on overall decision-making have been well described. Due to the complex nature of decisions, there remains a need for studies to identify specific mechanisms of decision-making vulnerable to sleep loss. Bayesian perspectives of decision-making posit judgement formation during decision-making occurs via a process of integrating knowledge gleaned from past experiences (priors) with new information from current observations (likelihoods). We investigated the effects of sleep loss on the ability to integrate multiple sources of information during decision-making by reporting results from two experiments: the first implementing both sleep restriction (SR) and …

Poor Oral Health Is Associated With Inflammation, Aortic Valve Calcification, And Brain Volume Among Forager-Farmers, Benjamin C. Trumble, Matthew Schwartz, Andrew T. Ozga, Gary T. Schwartz, Christopher M. Stojanowski, Carrie L. Jenkins, Thomas Kraft, Angela R. Garcia, Daniel K. Cummings, Paul L. Hooper, Daniel Eid Rodriguez, Kenneth Buetow, Bret Beheim, Andrei Irimia, Gregory S. Thomas, Randall C. Thompson, Horus Team, Margaret Gatz, Jonathan Stieglitz, Caleb E. Finch, Michael Gurven, Hillard Kaplan

ESI Publications

Poor oral health is associated with cardiovascular disease and dementia. Potential pathways include sepsis from oral bacteria, systemic inflammation, and nutritional deficiencies. However, in post-industrialized populations, links between oral health and chronic disease may be confounded because the lower socioeconomic exposome (poor diet, pollution, low physical activity) often entails insufficient dental care. We assessed tooth loss, caries, and damaged teeth, in relation to cardiovascular and brain aging among the Tsimane, a subsistence population living a relatively traditional forager-horticulturalist lifestyle with poor dental health, but minimal cardiovascular disease and dementia. Dental health was assessed by a physician in 739 participants aged …

Testosterone Is Positively Associated With Coronary Artery Calcium In A Low Cardiovascular Disease Risk Population, Benjamin Trumble, Jacob Negrey, Stephanie V. Koebele, Randall C. Thompson, L. Samuel Wann, Adel H. Allam, Bret Beheim, M. Linda Sutherland, James D. Sutherland, Daniel Eid Rodriguez, David E. Michalik, Chris J. Rowan, Guido P. Lombardi, Angela R. Garcia, Daniel K. Cummings, Edmond Seabright, Sarah Alami, Thomas S. Kraft, Paul L. Hooper, Kenneth Buetow, Andrei Irimia, Margaret Gatz, Jonathan Stieglitz, Michael D. Gurven, Hillard Kaplan, Gregory S. Thomas, Tsimane Health And Life History Project Teams

ESI Publications

Background

In industrialized populations, low male testosterone is associated with higher rates of cardiovascular mortality. However, coronary risk factors like obesity impact both testosterone and cardiovascular outcomes. Here, we assess the role of endogenous testosterone on coronary artery calcium in an active subsistence population with relatively low testosterone levels, low cardiovascular risk and low coronary artery calcium scores.

Methodology

In this cross-sectional community-based study, 719 Tsimane forager-horticulturalists in the Bolivian Amazon aged 40+ years underwent computed tomography (49.8% male, mean age 57.6 years).

Results

Coronary artery calcium levels were low; 84.5% had no coronary artery calcium. Zero-inflated negative binomial models …

The Effect Of Wage Proposals On Efficiency And Income Distribution☆, Lara Ezquerra, Joaquín Gómez-Miñambres, Natalia Jiminez, Praveen Kujal

ESI Publications

Pre-play non-binding communication in organizations is prevalent. We study the implications of pre-play, private and public, wage proposals in labor markets. To that end, we develop a theoretical model from which we derive certain hypothesis that we test through a laboratory experiment. In the baseline, that depicts a typical labor market interaction, the employer makes a wage offer to the worker who may then accept or reject it. In subsequent treatments, workers, moving first, make private, non-binding, wage proposals to the employer. In a following treatment, the proposals are made public. Our findings suggest that both private and public wage …

Asymmetric Shocks In Contests: Theory And Experiment, Jian Song, Daniel Houser

ESI Publications

Under optimal tournament design, equilibrium effort is invariant to the shape of the mean-zero additive stochastic component, often referred to as a “shock” or “noise”. We report data from laboratory experiments providing the first test of this prediction. Consistent with theory, we find that average effort does not significantly differ between a negatively skewed and uniform shock distribution. In addition, we test a second theoretical prediction that, in winner tournaments, when the shock distribution is asymmetric as in our design, one should exert minimum effort whenever one's competitors are exerting above equilibrium effort. With a symmetric shock distribution as in …

What Did Adam Smith Mean? The Semantics Of The Opening Key Principles In The Wealth Of Nations, Bart J. Wilson, Gian Marco Farese

ESI Publications

We present a semantic and textual analysis of the first two chapters of the Wealth of Nations to elucidate the meaning of several of Adam Smith’s key ideas. Using the methodology of the Natural Semantic Metalanguage, we produce semantic explications of some of Adam Smith’s fundamental principles of economics phrased in simple and cross-translatable words. The extracts from the original text function as textual evidence and conceptual reference for the explications we present. We demonstrate that: (i) by reducing the principles as conceived by Smith to their core meanings, it is possible to resolve some interpretive ambiguities for general readers …

Metapopulation Dynamics Of Sars-Cov-2 Transmission In A Small-Scale Amazonian Society, Thomas Kraft, Edmond Seabright, Sarah Alami, Samuel M. Jenness, Paul L. Hooper, Bret Beheim, Helen Davis, Daniel K. Cummings, Daniel Eid Rodriguez, Maguin Gutierrez Cayuba, Emily J. Miner, Xavier De Lamballerie, Lucia Inchauste, Stéphane Priet, Benjamin Trumble, Jonathan Stieglitz, Hillard Kaplan, Michael Gurven

ESI Publications

The severity of infectious disease outbreaks is governed by patterns of human contact, which vary by geography, social organization, mobility, access to technology and healthcare, economic development, and culture. Whereas globalized societies and urban centers exhibit characteristics that can heighten vulnerability to pandemics, small-scale subsistence societies occupying remote, rural areas may be buffered. Accordingly, voluntary collective isolation has been proposed as one strategy to mitigate the impacts of COVID-19 and other pandemics on small-scale Indigenous populations with minimal access to healthcare infrastructure. To assess the vulnerability of such populations and the viability of interventions such as voluntary collective isolation, we …

Apolipoprotein-Ε4 Is Associated With Higher Fecundity In A Natural Fertility Population, Benjamin Trumble, Mia Charifson, Tom Kraft, Angela R. Garcia, Daniel K. Cummings, Paul L. Hooper, Amanda J. Lea, Daniel Eid Rodriguez, Stephanie V. Koebele, Kenneth Buetow, Bret Beheim, Riana Minocher, Maguin Gutierrez, Gregory S. Thomas, Margaret Gatz, Jonathan Stieglitz, Caleb E. Finch, Hillard Kaplan, Michael Gurven

ESI Publications

In many populations, the apolipoprotein-ε4 (APOE-ε4) allele increases the risk for several chronic diseases of aging, including dementia and cardiovascular disease; despite these harmful effects at later ages, the APOE-ε4 allele remains prevalent. We assess the impact of APOE-ε4 on fertility and its proximate determinants (age at first reproduction, interbirth interval) among the Tsimane, a natural fertility population of forager-horticulturalists. Among 795 women aged 13 to 90 (20% APOE-ε4 carriers), those with at least one APOE-ε4 allele had 0.3 to 0.5 more children than (ε3/ε3) …

Energetic Costs Of Testosterone In Two Subsistence Populations, Benjamin C. Trumble, Herman Pontzer, Jonathan Stieglitz, Daniel K. Cummings, Brian Wood, Melissa Emery Thompson, David Raichlen, Bret Beheim, Gandhi Yetish, Hillard Kaplan, Michael Gurven

ESI Publications

Objective

Testosterone plays a role in mediating energetic trade-offs between growth, maintenance, and reproduction. Investments in a high testosterone phenotype trade-off against other functions, particularly survival-enhancing immune function and cellular repair; thus only individuals in good condition can maintain both a high testosterone phenotype and somatic maintenance. While these effects are observed in experimental manipulations, they are difficult to demonstrate in free-living animals, particularly in humans. We hypothesize that individuals with higher testosterone will have higher energetic expenditures than those with lower testosterone.

Methods

Total energetic expenditure (TEE) was quantified using doubly labeled water in n = 40 Tsimane forager-horticulturalists …

Reproductive Inequality In Humans And Other Mammals, Cody T. Ross, Paul L. Hooper, Jennifer E. Smith, Adrian V. Jaeggi, Eric Alden Smith, Sergey Gavrilets, Fatema Tuz Zohora, John Ziker, Dimitris Xygalatas, Emily E. Wroblewski, Brian Wood, Bruce Winterhalder, Kai P. Willführ, Aiyana K. Willard, Kara Walker, Christopher Von Rueden, Eckart Voland, Claudia Valeggia, Bapu Vaitla, Samuel Urlacher, Mary Towner, Chun-Yi Sum, Lawrence S. Sugiyama, Karen B. Strier, Kathrine Starkweather, Daniel Major-Smith, Mary Shenk, Rebecca Sear, Edmond Seabright, Ryan Schacht, Brooke Scelza, Shane Scaggs, Jonathan Salerno, Caissa Revilla-Minaya, Daniel Redhead, Anne Pusey, Benjamin Grant Purzycki, Eleanor A. Power, Anne Pisor, Jenni Pettay, Susan Perry, Abigail E. Page, Luis Pacheco-Cobos, Kathryn Oths, Seung-Yun Oh, David Nolin, Daniel Nettle, Cristina Moya, Andrea Bamberg Migliano, Karl J. Mertens, Rita A. Mcnamara, Richard Mcelreath, Siobhan Mattison, Eric Massengill, Frank Marlowe, Felicia Madimenos, Shane Macfarlan, Virpi Lummaa, Roberto Lizarralde, Ruizhe Liu, Melissa A. Liebert, Sheina Lew-Levy, Paul Leslie, Joseph Lanning, Karen Kramer, Jeremy Koster, Hillard S. Kaplan, Bayarsaikhan Jamsranjav, A. Magdalena Hurttado, Kim Hill, Barry Hewlett, Samili Helle, Thomas Headland, Janet Headland, Michael Gurven, Gianluca Grimalda, Russell Greaves, Christopher D. Golden, Irene Godoy, Mhairi Gibson, Claire El Mouden, Mark Dyble, Patricia Draper, Sean Downey, Angelina L. Demarco, Helen Elizabeth Davis, Stefani Crabtree, Carmen Cortez, Heidi Colleran, Emma Cohen, Gregory Clark, Julia Clark, Mark A. Caudell, Chelsea E. Carminito, John Bunce, Adam Boyette, Samuel Bowles, Tami Blumenfield, Bret Beheim, Stephen Beckerman, Quentin Atkinson, Coren Apicella, Nurul Alam, Monique Borgerhoff Mulder

ESI Publications

To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited …

Atherosclerosis In Indigenous Tsimane: A Contemporary Perspective, Randall C. Thompson, Gregory S. Thomas, Angela D. Neuneubel, Ashna Mahadev, Benjamin Trumble, Edmond Seabright, Daniel K. Cummings, Jonathan Stieglitz, Michael Gurven, Hillard Kaplan

ESI Publications

The Horus and other research teams have found that atherosclerosis is not uncommon in ancient people through the study of their mummified remains (Murphy et al., 2003; Allam et al., 2009, 2011; Thompson et al., 2013, 2014). However, some have postulated that traditional hunter-gatherers are in some ways healthier than modern people and that they had very little atherosclerotic disease (O’Keefe et al., 2010). The aim of this study was to evaluate the burden of atherosclerosis in a population alive today but living a traditional lifestyle similar to that experienced by past populations. This led to the Tsimane Health and …

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 …

Introducing New Forms Of Digital Money: Evidence From The Laboratory, Gabriele Camera

ESI Publications

Central banks may soon issue currencies that are entirely digital (CBDCs) and possibly interest bearing. A strategic analytical framework is used to investigate this innovation in the laboratory, contrasting a traditional “plain” tokens baseline to treatments with “sophisticated” interest-bearing tokens. In the experiment, this theoretically beneficial innovation precluded the emergence of a stable monetary system, reducing trade and welfare. Similar problems emerged when sophisticated tokens complemented or replaced plain tokens. This evidence underscores the advantages of combining theoretical with experimental investigation to provide insights for payments systems innovation and policy design.

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 …

Unfair Commercial Practices In A Pit Market: Evidence From An Artefactual Field Experiment, Francesco Bogliacino, Rafael Charris, Cristiano Codagnone, Frans Folkvord, Felipe Montealegre, Francisco Lupiáñez-Villanueva

ESI Publications

Commercial practices such as drip pricing, reference pricing and best-price guarantee can be used to set higher prices and mislead consumers, but protective measures can restore efficiency. In a placebo-controlled market experiment, we examined a treatment allowing for the use and misuse of commercial practices. Three additional treatments tested the effects of formal sanctions, informal sanctions and a regret nudge. We found that commercial practices led to higher prices, cheating was systematic and regret nudging was ineffective. Furthermore, formal and informal sanctions reduced both the likelihood of using commercial practices and the likelihood of cheating, leading to welfare increases.

Cultural Transmission Vectors Of Essential Knowledge And Skills Among Tsimane Forager-Farmers, Eric Schniter, Hillard Kaplan, Michael Gurven

ESI Publications

Humans transmit cultural information to others in a variety of ways that can affect productivity, cultural success, and ultimately fitness. Not all potential transmitters are expected to be equally preferred by learners or equally willing to influence their culture acquisition. Across socioeconomic opportunities and ages in the human life course, costs and benefits to both learners and potential transmitters are expected to vary, affecting rates of culture transmission from different vectors. Here we examine reported patterns of culture transmission contributing to 92 essential skills among a sample of 421 Tsimane forager-farmers native to Bolivia. Consistent with the expectation that the …

The Primacy Of Property; Or, The Subordination Of Property Rights, Bart J. Wilson

ESI Publications

A property right, the standard view maintains, is a proper subset of the most complete and comprehensive set of incidents for full ownership of a thing. The subsidiary assumption is that the pieces that are property rights compose the whole that is ownership or property, i.e., that property rights explain property. In reversing the standard view I argue that (1) a custom of intelligent and meaningful human action explains property and that (2) as a custom, property is a historical process of selecting actions conditional on the context. My task is to explain how a physical world of human bodies …

When Do Security Markets Aggregate Dispersed Information?, Brice Corgnet, Cary Deck, Mark Desantis, Kyle Hampton, Erik O. Kimbrough

ESI Publications

We attempt to replicate a seminal paper that offered support for the rational expectations hypothesis and reported evidence that markets with certain features aggregate dispersed information. The original results are based on only a few observations, and our attempt to replicate the key findings with an appropriately powered experiment largely fails. The resulting poststudy probability that market performance is better described by rational expectations than the prior information (Walrasian) model under the conditions specified in the original paper is very low. As a result of our failure to replicate, we investigate an alternate set of market features that combines aspects …

Social Norms And Dishonesty Across Societies, Diego Aycinena, Lucas Rentschler, Benjamin Beranek, Jonathan F. Schulz

ESI Publications

Social norms have long been recognized as an important factor in curtailing antisocial behavior, and stricter prosocial norms are commonly associated with increased prosocial behavior. In this study, we provide evidence that very strict prosocial norms can have a perverse negative relationship with prosocial behavior. In laboratory experiments conducted in 10 countries across 5 continents, we measured the level of honest behavior and elicited injunctive norms of honesty. We find that individuals who hold very strict norms (i.e., those who perceive a small lie to be as socially unacceptable as a large lie) are more likely to lie to the …

A Universally Translatable Explication Of Adam Smith's Famous Proposition On "The Extent Of The Market", Bart J. Wilson, Gian Marco Farese

ESI Publications

Following Adam Smith’s line of argument, we examine the semantics of four economic principles in Chapter III of the Wealth of Nations that compose his famous proposition “that the division of labour is limited by the extent of the market.” We apply the Natural Semantic Metalanguage framework in linguistics to produce a series of explications that are clear and plain, cross-translatable into any language, intelligible to twenty-first-century readers, and faithfully close to the original text. Our paper explicates Smith’s logical argument in Chapter III and demonstrates how his ideas can be shared among speakers with different linguacultural backgrounds in line …

Preventing (Panic) Bank Runs, Hubert János Kiss, Ismael Rodriguez-Lara, Alfonso Rosa-Garcia

ESI Publications

We study experimentally an instrument to prevent bank runs in healthy banks. In particular, we extend the basic bank-run game, where depositors choose between withdrawing or keeping their money deposited, with a third option, the possibility to relocate funds to a priority account that is less profitable, but which guarantees a payoff even in a bank run. Theoretically, the use of this instrument dominates withdrawals for depositors without liquidity needs, and given this fact, depositors should optimally keep their deposits in the bank, so no bank run shall happen. In our experiment, we find evidence that the mechanism reduces not …

Review Of Religion And The Rise Of Capitalism, Jared Rubin

ESI Publications

A review of Religion and the Rise of Capitalism by Benjamin M. Friedman

Prevalence Of Dementia And Mild Cognitive Impairment In Indigenous Bolivian Forager-Horticulturalists, Margaret Gatz, Wendy J. Mack, Helena C. Chui, E. Meng Law, Giuseppe Barisano, M. Linda Sutherland, James D. Sutherland, Daniel Eid Rodriguez, Raul Quispe Gutierrez, Juan Copajira Adrian, Jesus Bani Cuata, Amy R. Borenstein, Ellen E. Waters, Andrei Irimia, Christopher J. Rowan, L. Samuel Wann, Adel H. Allam, Randall C. Thompson, Michael I. Miyamoto, David E. Michalik, Daniel K. Cummings, Edmond Seabright, Angela R. Garcia, Paul L. Hooper, Thomas S. Kraft, Caleb E. Finch, Gregory S. Thomas, Jonathan Stieglitz, Benjamin C. Trumble, Michael D. Gurven, Hillard Kaplan

ESI Publications

Introduction

We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle.

Methods

Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans.

Results

Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. …

Laboratory Experiments Of Land Assembly Without Eminent Domain, Mark Desantis, Matthew W. Mccarter, Abel Winn

ESI Publications

The authors use laboratory experiments to test two self-assessment tax mechanisms for facilitating land assembly. One mechanism is incentive compatible with a complex tax function, while the other uses a flat tax rate to mitigate implementation concerns. Sellers publicly declare a price for their land. Overstating its true value is penalized by using the declared price to assess a property tax; understating its value is penalized by allowing developers to buy the property at the declared price. The authors find that both mechanisms increase the rate of land assembly and gains from trade relative to a control in which sellers’ …

Human Milk Oligosaccharide Compositions Illustrate Global Variations In Early Nutrition, Anita Vinjamuri, Jasmine C. C. Davis, Sarah M. Totten, Lauren D. Wu, Laura D. Klein, Melanie Martin, Ea Quinn, Brooke Scelza, Alicia Breakey, Michael Gurven, Grazyna Jasienska, Hillard Kaplan, Claudia Valeggia, Katie Hinde, Jennifer T. Smilowitz, Robin M. Bernstein, Angela M. Zivkovic, Michael J. Barratt, Jeffrey I. Gordon, Mark A. Underwood, David A. Mills, J. Bruce German, Carlito B. Lebrilla

ESI Publications

Background

Human milk oligosaccharides (HMOs) are an abundant class of compounds found in human milk and have been linked to the development of the infant, and specifically the brain, immune system, and gut microbiome.

Objectives

Advanced analytical methods were used to obtain relative quantitation of many structures in approximately 2000 samples from over 1000 mothers in urban, semirural, and rural sites across geographically diverse countries.

Methods

LC-MS−based analytical methods were used to profile the compounds with broad structural coverage and quantitative information. The profiles revealed their structural heterogeneity and their potential biological roles. Comparisons of HMO compositions were made between …

Economics Of Markets: Neoclassical Theory, Experiments, And Theory Of Classical Price Discovery, Sabiou M. Inoua, Vernon L. Smith

ESI Publications

This book establishes that neoclassical economics based on the marginal utility calculus failed to derive a theory of consumer market price discovery consistent with the experimental market evidence. Such markets involve inherently discrete final-demand items bought for consumption and not subject to resale. Classical economists following Adam Smith articulated a rich narrative of price discovery theory consistent with experimental evidence based on operational concepts of discrete demand values (maximum willingness-to-pay), and symmetrically, supply costs (minimum willingness-to-accept). We develop and extend a mathematical model of classical market price formation. Chapter 1 & 2 describes this theme and chapter 3 connects it …

Prosocial Option Increases Women’S Entry Into Competition, Alessandra Cassar, Mary L. Rigdon

ESI Publications

We provide evidence that women enter competitions at the same rate as men when the incentive for winning includes the option to share part of the rewards with the losers (i.e., when the incentive system is socially oriented). Using an experiment (with N = 238 subjects from three laboratories), we find that about 16% more men than women choose to compete in the standard tournament; this gender gap is eliminated in the socially oriented incentive treatment. While men’s choice to compete remains unchanged, at around 52% in both conditions, women increase their entry rate from 35% in the standard tournament …

Helminth Infection Is Associated With Dampened Cytokine Responses To Viral And Bacterial Stimulations In Tsimane Forager-Horticulturalists, India A. Schneider-Crease, Aaron D. Blackwell, Thomas S. Kraft, Melissa Emery Thompson, Ivan Maldonado Suarez, Daniel K. Cummings, Jonathan Stieglitz, Noah Snyder-Mackler, Michael Gurven, Hillard Kaplan, Benjamin C. Trumble

ESI Publications

Background

Soil-transmitted helminths (STHs) and humans share long co-evolutionary histories over which STHs have evolved strategies to permit their persistence by downregulating host immunity. Understanding the interactions between STHs and other pathogens can inform our understanding of human evolution and contemporary disease patterns. Methodology

We worked with Tsimane forager-horticulturalists in the Bolivian Amazon, where STHs are prevalent. We tested whether STHs and eosinophil levels—likely indicative of infection in this population—are associated with dampened immune responses to in vitro stimulation with H1N1 and lipopolysaccharide (LPS) antigens. Whole blood samples (n = 179) were treated with H1N1 vaccine and LPS and …

Anything For A Cheerio: Brown Capuchins (Sapajus [Cebus] Apella) Consistently Coordinate In An Assurance Game For Unequal Payoffs, Lauren M. Robinson, Mayte Martínez, Kelly L. Leverett, Mattea S. Rossettie, Bart J. Wilson, Sarah F. Brosnan

ESI Publications

Unequal outcomes disrupt cooperation in some situations, but this has not been tested in the context of coordination in economic games. To explore this, we tested brown capuchins (Sapajus [Cebus] apella) on a manual version of the Stag Hunt (or Assurance) Game, in which individuals sequentially chose between two options, Stag or Hare, and were rewarded according to their choices and that of their partner. Typically, coordination on Stag results in an equal highest payout, whereas coordinating on Hare results in a guaranteed equal but lower payoff and uncoordinated play results in the lowest payoff when playing …

Do Wealth And Inequality Associate With Health In A Small-Scale Subsistence Society?, Adrian V. Jaeggi, Aaron D. Blackwell, Christopher Von Rueden, Benjamin C. Trumble, Jonathan Stieglitz, Angela R. Garcia, Thomas S. Kraft, Bret A. Beheim, Paul L. Hooper, Hillard Kaplan, Michael Gurven

ESI Publications

In high-income countries, one’s relative socio-economic position and economic inequality may affect health and well-being, arguably via psychosocial stress. We tested this in a small-scale subsistence society, the Tsimane, by associating relative household wealth (n = 871) and community-level wealth inequality (n = 40, Gini = 0.15–0.53) with a range of psychological variables, stressors, and health outcomes (depressive symptoms [n = 670], social conflicts [n = 401], non-social problems [n = 398], social support [n = 399], cortisol [n = 811], body mass index [n = 9,926], blood pressure [n = 3,195], self-rated health [n = 2523], morbidities [n = …