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Humans rely on both kin and non-kin social ties for a wide range of support. In patrilocal societies that practice village exogamy, women can face the challenge of building new supportive networks when they move to their husband's village and leave many genetic kin behind. In this paper, we track how women from 10 diverse communities in rural Bangladesh build supportive networks after migrating to their husband's village, comparing their trajectories with women who remained in their childhood village (Bengali: n = 317, Santal: n = 36, Hajong: n = 39, Mandi: n = 36). Women who migrated for marriage started with almost no adult close kin (mean 0.1) compared to women who remained in their childhood village (mean 2.4). However, immigrants compensated for the lack of genetic kin by a combination of close affinal kin and close friends. By their late 20s, immigrants reported substantially more non-kin friends than did non-immigrants (mean 1.4 versus 1.1) and a comparable number of supportive partners in several domains. These findings raise questions about the functions and quality of these different social ties and how different composition of supportive networks may provide different opportunities for women in these settings. This article is part of the theme issue ‘Cooperation among women: evolutionary and cross-cultural perspectives’.

Social scientists have increasingly used asset‐based wealth scores, like the Demographic and Health Survey (DHS) wealth index, to assess economic disparities. However, current indices primarily capture wealth in globalized market economies, thus ignoring other forms of prosperity, such as success in agricultural activities. Using a simple extension to the standard estimation of the DHS wealth index, we describe procedures for estimating an agricultural wealth index (AWI) that complements market‐based wealth indices by capturing household success in agricultural activities. We apply this procedure to household data from 129 DHS surveys from over 40 countries with sufficient land and livestock data to estimate a reliable and consistent AWI. We assess the construct validity of the AWI using benchmarks of growth in both adults and children. This alternative measure of wealth provides new opportunities for understanding the causes and consequences of wealth inequality, and how success along different dimensions of wealth creates different social opportunities and constraints for health and well‐being.

Hamilton's rule predicts that altruism should depend on costs incurred and benefits provided, but these depend on the relative needs of the donor and recipient. Rewriting Hamilton's rule to account for relative need suggests an amplifying effect of need on relatedness, but not necessarily other relationship qualities. In a reanalysis of three studies of social discounting and a new replication, we find that relative need amplifies the effects of relatedness on giving in two samples of U.S. adults recruited online, but not U.S. undergraduates or Indian adults recruited online. Among U.S. online participants, the effect of genetic kinship was greater when the partner was perceived to be in higher need than when in lower need. In the other samples, relatedness and greater partner need were associated with greater giving, but the effect of relatedness on giving was not significantly amplified by need. Need never amplified the effect of social closeness on giving, although it did diminish the effect of closeness in U.S. undergraduates, likely reflecting a ceiling effect. These results confirm predictions from a modification of Hamilton's rule in a sample of U.S. adults, but raise important questions about why they hold in some samples but not others. They also illustrate the importance of understanding how contextual factors, such as relative need, can moderate the importance of common variables used in evolutionary cost-benefit analyses.

OBJECTIVE: We investigate how alcohol use and friendship co-evolve during students’ transition to university. We discern effects of peer influence from friend selection based on alcohol use, whether such effects vary in strength across the school year, and whether alcohol has different effects on friendship formation versus friendship maintenance. METHOD: We gathered data on friendships, alcohol use, and binge drinking from 300 residence hall students (71% female) at a large, public U.S. university. Surveys were conducted at four time points during the 2015–2016 academic year. We used a stochastic actor-oriented model to test whether alcohol use was influenced by one’s friends, while simultaneously testing for friend selection based on alcohol use and related network processes. RESULTS: Students were 7.0 times more likely to drink alcohol weekly if all versus none of their friends drank weekly and 6.8 times more likely to binge drink when all versus none of their friends engaged in binge drinking, after we controlled for friend selection. Alcohol use differentially affected friendship creation and maintenance in a complex manner: (a) weekly drinkers were more likely to form new friendships and dissolve existing friendships than nondrinkers and (b) similarity on drinking fostered new friendships but had no effect on friendship persistence. CONCLUSIONS: Friends influence one another’s weekly drinking and binge drinking, whereas conversely, alcohol use contributes to both friendship formation and friendship instability.

The many tools that social and behavioral scientists use to gather data from their fellow humans have, in most cases, been honed on a rarefied subset of humanity: highly educated participants with unique capacities, experiences, motivations, and social expectations. Through this honing process, researchers have developed protocols that extract information from these participants with great efficiency. However, as researchers reach out to broader populations, it is unclear whether these highly refined protocols are robust to cultural differences in skills, motivations, and expected modes of social interaction. In this paper, we illustrate the kinds of mismatches that can arise when using these highly refined protocols with nontypical populations by describing our experience translating an apparently simple social discounting protocol to work in rural Bangladesh. Multiple rounds of piloting and revision revealed a number of tacit assumptions about how participants should perceive, understand, and respond to key elements of the protocol. These included facility with numbers, letters, abstract number lines, and 2D geometric shapes, and the treatment of decisions as a series of isolated events. Through on-the-ground observation and a collaborative refinement process, we developed a protocol that worked both in Bangladesh and among US college students. More systematic study of the process of adapting common protocols to new contexts will provide valuable information about the range of skills, motivations, and modes of interaction that participants bring to studies as we develop a more diverse and inclusive social and behavioral science.

The increasing availability of large digital corpora of cross-linguistic data is revolutionizing many branches of linguistics. Overall, it has triggered a shift of attention from detailed questions about individual features to more global patterns amenable to rigorous, but statistical, analyses. This engenders an approach based on successive approximations where models with simplified assumptions result in frameworks that can then be systematically refined, always keeping explicit the methodological commitments and the assumed prior knowledge. Therefore, they can resolve disputes between competing frameworks quantitatively by separating the support provided by the data from the underlying assumptions. These methods, though, often appear as a ‘black box’ to traditional practitioners. In fact, the switch to a statistical view complicates comparison of the results from these newer methods with traditional understanding, sometimes leading to misinterpretation and overly broad claims. We describe here this evolving methodological shift, attributed to the advent of big, but often incomplete and poorly curated data, emphasizing the underlying similarity of the newer quantitative to the traditional comparative methods and discussing when and to what extent the former have advantages over the latter. In this review, we cover briefly both randomization tests for detecting patterns in a largely model-independent fashion and phylolinguistic methods for a more model-based analysis of these patterns. We foresee a fruitful division of labor between the ability to computationally process large volumes of data and the trained linguistic insight identifying worthy prior commitments and interesting hypotheses in need of comparison.

PurposeIdentify how higher Body Mass Index (BMI) and weight discrimination are associated with romantic relationship formation and termination in young adults, and if the association was consistent for males and females.MethodsFirst-year students (N = 1096) at entry to university (Time 1) provided BMI and self-reports of weight discrimination and romantic relationship status (in a relationship vs single); 550 were successfully resampled four months later (Time 2). Logistic generalized estimating equations (GEEs) examined if Time 1 relationship status was predicted by BMI and weight discrimination. Logistic GEEs were used to determine if Time 1 BMI and weight discrimination predicted Time 2 relationship status for the strata of students in, and out, of a relationship at Time 1.ResultsAt baseline, students were less likely to be in a relationship if they had a higher BMI (OR = 0.94, 95% CI = 0.92, 0.96) or reported weight discrimination (OR = 0.69, 95% CI = 0.53, 0.90). When stratified by gender, the association between higher BMI and weight discrimination with relationship status was only observed for females. Longitudinally, a BMI-based selection effect was observed for romantic relationship formation, but not termination. Of the students who were single at Time 1, each one unit higher baseline BMI decreased the odds of the student transitioning to a relationship by 9% at Time 2 (OR = 0.91, 95% CI = 0.85, 0.96). When stratified by gender the association of higher BMI decreased odds of relationship formation was only significant for females. No weight discrimination differences for selection in or out of a romantic relationship were observed.ConclusionsThese findings suggest a weight-related selection effect for romantic relationship initiation, but not termination, in young female adults with lower BMIs. Weight discrimination was not associated with romantic relationship initiation or termination in this sample.

ObjectiveTo examine if first-year roommates made similar meal plan decisions.MethodsResidence information for 1186 first-year students (N = 593 roommate pairs) and 559 floormates was obtained for the 2015-2016 academic year. Linear generalized estimating equations (GEEs) were used to examine if the number of meals students used over the semester was higher if their roommate used their meal plan more frequently. A logistic GEE examined joint meal plan usage between students and roommates for each month of the semester. To determine if residence, rather than roommate, explained the results, a simulation was conducted by randomly assigning the floormates to a same-sex roommate.ResultsThe number of meals students used in spring was higher if the students' roommate had used more meals in spring, even after controlling for the number of meals students used in fall (Female: β = 0.07, 99% CI = 0.00, 0.13; Male: β = 0.10, 99% CI = 0.02, 0.18). Students were more likely to use a meal with their roommate if they were on the same meal plan (Female: OR = 1.61, 99% CI = 1.27, 2.04; Male: OR = 1.57, 99% CI = 1.09, 2.25), and less likely after the first month of being roommates (Female: OR = 0.57-0.25; Male: OR = 0.50-0.22; p

Studies have shown mixed associations between wealth and fertility, a finding that has posed ongoing puzzles for evolutionary theories of human reproduction. However, measures of wealth do not simply capture economic capacity, which is expected to increase fertility. They can also serve as a proxy for market opportunities available to a household, which may reduce fertility. The multifaceted meaning of many wealth measures obscures our ability to draw inferences about the relationship between wealth and fertility. Here, we disentangle economic capacity and market opportunities using wealth measures that do not carry the same market-oriented biases as commonly used asset-based measures. Using measures of agricultural and market-based wealth for 562,324 women across 111,724 sampling clusters from 151 DHS surveys in 64 countries, we employ a latent variable structural equation model to estimate (a) latent variables capturing economic capacity and market opportunity and (b) their effects on completed fertility. Market opportunities had a consistent negative effect on fertility, while economic capacity had a weaker but generally positive effect on fertility. The results show that the confusion between operational measures of wealth and the concepts of economic capacity can impede our understanding of how material resources and market contexts shape reproduction.

Background Valid measurement of hemoglobin is important for tracking and targeting interventions. This study compares hemoglobin distributions between surveys matched by country and time from The Demographic and Health Survey (DHS) Program and the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project. Methods Four pairs of nationally representative surveys measuring hemoglobin using HemoCue® with capillary (DHS) or venous (BRINDA) blood were matched by country and time. Data included 17,719 children (6–59 months) and 21,594 non-pregnant women (15–49 y). Across paired surveys, we compared distributional statistics and anemia prevalence. Results Surveys from three of the four countries showed substantial differences in anemia estimates (9 to 31 percentage point differences) which were consistently lower in BRINDA compared to DHS (2 to 31 points for children, 1 to 16 points for women). Conclusion We identify substantial differences in anemia estimates from surveys of similar populations. Further work is needed to identify the cause of these differences to improve the robustness of anemia estimates for comparing populations and tracking improvements over time.

OBJECTIVES: Lack of wealth (poverty) impacts almost every aspect of human biology. Accordingly, many such studies include its assessment. In almost all cases, approaches to assessing poverty are based in lack of success within cash economies (e.g., lack of income, employment). But this operationalization deflects attention from alternative forms of poverty that may have the most substantial influence on human wellbeing. We test how a multidimensional measure of poverty that considers agricultural assets expands the explanatory power of the construct of household poverty by associating it with one key aspect of wellbeing: symptoms of mental health. METHODS: We use the case of three highly vulnerable but distinctive communities in Haiti—urban, town with a rural hinterland, and rural. Based on survey responses from adults in 4,055 geographically sampled households, linear regression models were used to predict depression and anxiety symptom levels controlling for a wide range of covariates related to detailed measures of material poverty, including cash-economy and agricultural assets, income, financial stress, and food insecurity. RESULTS: Household assets related to the cash economy were significantly associated with lower (i.e. better) depression scores (-0.3, [95% CI: -0.6 to, -0.0]) but unrelated to anxiety scores (-0.04 [95% CI: -0.39 to 0.30]).). Agricultural wealth was significantly – and more strongly - associated with both reductions in depression symptoms (-0.8 [95% CI: -1.6 to -0.2]) and anxiety symptoms (-0.9 [95% CI: -1.6 to -0.2]). These associations were consistent across the three sites, except in the fully urban site in Port-au-Prince where level of depression symptoms was not significantly associated with household agricultural wealth. CONCLUSIONS: Standard measures of poverty based on success in the cash economy can mask important associations between poverty and wellbeing, in this case related to household-level subsistence capacity and crucial food-producing household assets.

OBJECTIVES Current standards for comparing stunting across human populations assume a universal model of child growth. Such comparisons ignore population differences that are independent of deprivation and health outcomes. This article partitions variation in height-for-age that is specifically associated with deprivation and health outcomes to provide a basis for cross-population comparisons. MATERIALS AND METHODS Using a multilevel model with a sigmoid relationship of resources and growth, we partition variation in height-for-age z-scores (HAZ) from 1.5 million children across 70 countries into two components: (1) "accrued HAZ" shaped by environmental inputs (e.g., undernutrition, infectious disease, inadequate sanitation, poverty) and (2) a country-specific "basal HAZ" independent of such inputs. We validate these components against population-level infant mortality rates and assess how these basal differences may affect cross-population comparisons of stunting. RESULTS Basal HAZ differs reliably across countries (range of approximately 1.5 SD) and is independent of measures of infant mortality. By contrast, accrued HAZ captures stunting as impaired growth due to deprivation and is more closely associated with infant mortality than observed HAZ. Assessing stunting prevalence by accrued HAZ suggest that populations in West Africa and Haiti suffer much greater levels of stunting than indicated by observed HAZ. DISCUSSION Current universal standards may dramatically underestimate stunting in populations with taller basal HAZ. Relying on observed HAZ rather than accrued HAZ may also lead to inappropriate cross-population comparisons, such as concluding that Haitian children enjoy better conditions for growth than do Indian or Guatemalan children.

Contemporary humans occupy the widest range of socioeconomic environments in their evolutionary history, and this has revealed unprecedented environmentally-induced plasticity in physical growth. This plasticity also has limits, and identifying those limits can help researchers: (1) parse when population differences arise from environmental inputs or not and (2) determine when it is possible to infer socioeconomic disparities from disparities in body form. To illustrate potential limits to environmental plasticity, we analyze body mass index (BMI) and height data from 1,768,962 women and 207,341 men (20-49 y) living in households exhibiting 1000-fold variation in household wealth (51 countries, 1985-2017, 164 surveys) across four world regions-sub-Saharan Africa, South Asia, Latin America, and North Africa and the Middle East. We find that relationships of environmental inputs with both mean height and BMI bottom out at roughly 100-700 USD per capita household wealth (2011 international units, PPP), but at different basal BMIs and basal heights for different regions. The relationship with resources tops out for BMI at around 20 K-35 K USD for women, with growth potential due to environmental inputs in the range of 6.2-8.4 kg/m2. By contrast, mean BMI for men and mean height for both sexes remains sensitive to environmental inputs even at levels far above the low- and middle-income samples studied here. This suggest that further work integrating comparable data from low- and high-income samples should provide a better picture of the full range of environmental inputs on human height and BMI. We conclude by discussing how neglecting such population-specific limits to human growth can lead to erroneous inferences about population differences.

Some researchers have proposed the prevalence of food insecurity among college students is high due to students&rsquo, meal plans providing insufficient meals. The association between college students&rsquo, food security status and their meal plans have not yet been examined. In this study, United States (US) first year college students (N = 534) self-reported their food security status in the Fall 2015 and/or Spring 2016 semester(s). Objective measures of students&rsquo, meal plans were obtained from the university. Logistic generalized estimating equations (GEEs) were used to determine if students&rsquo, meal plan, and meal plan use, predicted food insecurity. Linear GEEs were used to examine several potential reasons for lower meal plan use. We found that students did not use all of their available meals. Compared to students on the most expensive (unlimited) meal plan, students on the cheapest (8 meals/week) meal plan were the most likely to report food insecurity (OR = 2.2, 95% CI = 1.2, 4.1). However, in the Fall semester, 26% of students on unlimited meal plans also reported food insecurity. For students on the 180 meals/semester meal plan, food insecurity was associated with using fewer meals (OR = 0.9, 95% CI = 0.8, 1.0). Students who worked tended to use their meal plan less (&beta, = &minus, 1.3, 95% CI = &minus, 2.3, &minus, 0.3). Students are reporting food insecurity while having meals left in their meal plan.

A growing body of research among college students has estimated remarkably high levels of food insecurity when compared to food insecurity estimates from the general population over the past decade, with recent literature reviews reporting average prevalence rates of 33–51% compared to 9.8% among U.S. adults. Given these high rates of food insecurity, policymakers at the state- and federal-levels are considering legislation to better understand and ultimately alleviate food insecurity in the college student population. Further, the National Postsecondary Student Aid Study will soon collect national surveillance data on college student food insecurity. However, emerging research suggests that existing food insecurity measurement tools may not perform as expected when used with college students. Indeed, there is no food insecurity measure that has been validated for use with college students. The purpose of this commentary is to discuss the current state of food insecurity measurement among college students and set a course for more meaningful measurement in the college-student population that produces consistent and comparable estimates of food insecurity.

Each year, hundreds of articles in population health and nutrition, many in high-profile journals, use standard cutoffs based on weight and height as assessments of obesity and undernutrition. These global efforts to monitor overweight and underweight often rest on the assumption that ethnic differences in underlying body form are sufficiently small to permit universal anthropometric cutoffs for comparing excess and insufficient body fat across populations. However, a century of work in human biological variation suggests that human populations can vary dramatically in underlying body form in a way that may require population-sensitive cutoffs for monitoring. Here, we describe recently developed methods that can provide population-sensitive assessments of both excess and insufficient energy reserves in a wide range of countries. We use this approach to illustrate how worldwide variation in human body form is far more widespread than previously thought, and that it can occur at several geographic scales, including the level of world regions, countries and populations within countries. The findings also suggest that using standard cutoffs that ignore this variation can underestimate current obesity levels in adults by more than 400-500 million while also incorrectly prioritizing high-risk areas for undernutrition in children in key regions around the world.

Background There is ongoing debate about whether friends’ greater similarity in Body Mass Index (BMI) than non-friends is due to friend selection, shared environments, or peer influence. Methods First-year college students (n = 104) from a southwestern U.S. university were randomly assigned roommates during the university’s housing process, effectively removing friend selection effects. Participant BMI was measured up to four times (T1-T4) across 2015–2016. The influence of roommate baseline BMI (T1) on change in participant BMI over time (T2-T4) was analyzed using a linear mixed effects model adjusted for individual socio-demographics, linear time trends, baseline BMI, and physical clustering of students. A sensitivity analysis examining floormates was also conducted. Results Consistent with roommate influence, participants randomized to roommates with a higher BMI gained more weight between times T2 and T4 (β = 0.06; 95% CI = 0.02, 0.10). No shared environment effects (shared campus or floor) were found. Conclusions Randomly assigned roommates influenced each other's weight trajectories. This clarifies that BMI convergence can occur outside of friend selection or shared environments mechanisms.

Current scientific reforms focus more on solutions to the problem of reliability (e.g. direct replications) than generalizability. Here, we use a cross-cultural study of social discounting to illustrate the utility of a complementary focus on generalizability across diverse human populations. Social discounting is the tendency to sacrifice more for socially close individuals—a phenomenon replicated across countries and laboratories. Yet, when adapting a typical protocol to low-literacy, resource-scarce settings in Bangladesh and Indonesia, we find no independent effect of social distance on generosity, despite still documenting this effect among US participants. Several reliability and validity checks suggest that methodological issues alone cannot explain this finding. These results illustrate why we must complement replication efforts with investment in strong checks on generalizability. By failing to do so, we risk developing theories of human nature that reliably explain behaviour among only a thin slice of humanity.

Extreme biased sampling of research participants and the neglect of their cultural context are increasingly recognized as threats to the generalizability of much of what we know about human thought and behavior (1, 2). In addition to reinforcing narrow views of what it means to be human, these parochial research practices have also shaped the methodological core of the human sciences by favoring tasks that are tailored to the skills, motivations, and social expectations of a very rarefied set of humanity (3). Despite decades of calls for reform, there is little evidence that increasing awareness of this threat has led to changes in practice or publishing (2, 4). This special issue stems from the Sackler Colloquium on “Pressing Questions in the Study of Psychological and Behavioral Diversity” (September 7–9, 2017) designed to address these issues. Building on discussions emerging from two National Science Foundation-funded workshops held in 2016 and 2017, the colloquium convened scholars from a wide range of disciplines who have conducted important research with diverse populations. The colloquium participants identified barriers that discourage researchers from harnessing the full breadth of human diversity for understanding human thought and behavior. These included concerns about current peer review practices, methodological narrowness, lack of researcher diversity, and the need for theoretical frameworks that are sensitive to cultural, social, and ecological variation. Participants also shared innovations and insights from their own research that can foster and inform future investigations of human diversity. In this introduction, we highlight three threads that weave together the 10 papers in this special issue. The first thread documents the theoretical and practical payoffs of engaging with a broader range of participants (and the pitfalls of failing to do so). The second thread identifies barriers to pursuing such work and proposes potential solutions to overcome them. … [↵][1]1To whom correspondence should be addressed. Email: dhruschk{at}asu.edu. [1]: #xref-corresp-1-1

To estimate the absolute wealth of households using data from demographic and health surveys.We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures.The median absolute wealth estimates of 1,403,186 households were 2056 international dollars per capita (interquartile range: 723-6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R(2) = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes.Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality.Estimer la richesse absolue des ménages à l'aide de données provenant d'enquêtes démographiques et sanitaires.Nous avons développé un nouvel indicateur, l'estimation de la richesse absolue, à partir du classement de chaque ménage interrogé en fonction de ses biens matériels et du mode supposé de répartition des richesses entre les différents ménages interrogés. À l'aide de données provenant de 156 enquêtes démographiques et sanitaires menées dans 66 pays, nous avons produit des estimations de la richesse absolue des ménages. Nous avons validé la méthode en comparant la proportion des ménages définis comme pauvres dans nos estimations aux taux de pauvreté publiés par la Banque mondiale. Nous avons également comparé l'exactitude des estimations de la richesse absolue par rapport aux estimations de la richesse relative en vue de la prévision de mesures anthropométriques.Les estimations moyennes de la richesse absolue de 1.403.186 ménages indiquaient 2056 dollars internationaux par personne (intervalle interquartile: 723–6103). Une forte corrélation a été établie entre la proportion des ménages pauvres d'après les estimations de la richesse absolue et l'estimation du nombre de personnes vivant avec moins de 2,00 dollars des États-Unis par personne et par jour (R2 = 0,84) fournie par la Banque mondiale. Les estimations de la richesse absolue se sont révélées de meilleurs indicateurs des mesures anthropométriques que les indices de richesse relative.Les estimations de la richesse absolue offrent de nouvelles possibilités de recherche comparative pour évaluer les effets des ressources économiques sur le capital santé et humain, ainsi que les conséquences à long terme des changements et inégalités économiques sur la santé.Estimar la riqueza absoluta de los hogares utilizando los datos de encuestas demográficas y de salud.Se ha elaborado un nuevo sistema métrico, la estimación de la riqueza absoluta, basado en el rango de cada hogar encuestado en función de sus bienes materiales y la supuesta forma de distribución de la riqueza entre los hogares encuestados. Con los datos de 156 encuestas demográficas y de salud de 66 países, se ha hecho un cálculo de las estimaciones de la riqueza absoluta de los hogares. Se ha validado la metodología comparando la proporción de hogares definidos como pobres según nuestras estimaciones con los informes sobre pobreza publicados por el Banco Mundial. También se ha comparado la precisión de las estimaciones de riqueza absoluta frente a la riqueza relativa para las predicciones de medidas antropométricas.Las estimaciones medias de la riqueza absoluta de 1.403.186 hogares eran 2.056 dólares internacionales per cápita (rango intercuartílico: 723–6.103). La proporción de hogares pobres según las estimaciones de la riqueza absoluta estaba estrechamente relacionada con las estimaciones del Banco Mundial de la población que vive con menos de 2,00 dólares estadounidenses per cápita al día (Las estimaciones de la riqueza absoluta proporcionan nuevas oportunidades a la investigación comparativa para evaluar los efectos de los recursos económicos en la salud y el capital humano, así como las consecuencias para la salud a largo plazo del cambio económico y la desigualdad.تقدير حجم الثروة المطلق للأسرّ باستخدام بيانات مأخوذة من مسوح ديموغرافية وصحية.لقد قمنا بتطوير مقياس جديد، وهو تقدير حجم الثروة المطلق، استنادًا إلى ترتيب كل أسرة شملها المسح وفقًا لممتلكاتها المادية والشكل المفترض لتوزيع الثروة بين الأسر التي شملها المسح. باستخدام بيانات ناتجة عن 156 مسحًا من المسوح الديموغرافية والصحية في 66 بلدًا، قمنا بحساب تقديرات حجم الثورة المطلق للأسرّ. وقمنا بتوثيق مصداقية الطريقة من خلال مقارنة نسبة الأسرّ التي تم تحديدها كأسرّ فقيرة من خلال تقديراتنا وباستخدام المؤشرات العددية للفقر المنشورة من البنك الدولي. وقمنا أيضًا بمقارنة تقديرات دقة حجم الثروة المطلق في مقابل حجم الثروة النسبي للتنبؤ بالمقاييس الأنثروبومترية.بلغت تقديرات متوسط حجم الثروة المطلق لـ 1,403,186 أسرة هو 2,056 دولارًا دولية للفرد الواحد (المدى الربيعي: 723–6103). ارتبطت نسبة الأسر الفقيرة استنادًا إلى تقديرات حجم الثروة المطلق ارتباطًا قويًا بتقديرات البنك الدولي للسكان الذين يعيشون بأقل من دولارين أمريكيين للفرد الواحد يوميًا (توفر تقديرات حجم الثروة المطلق فرصًا جديدة ليقوم البحث المقارن بتقييم تأثيرات الموارد الاقتصادية على الصحة ورأس المال البشري، بالإضافة إلى العواقب الصحية طويلة الأمد للتغيير وعدم المساواة من الناحية الاقتصادية.旨在通过来自人口与健康调查中的数据估算家庭的绝对财富。.我们依据调查家庭的有形资产和假定的财富分配形态对各个调查家庭进行排名，并据此制定出一项新的指标，即绝对财富估值。通过从 66 个国家中开展的 156 项人口与健康调查中采集数据，我们计算出家庭的绝对财富估值。通过对比界定为贫困的家庭的比例，我们验证了该方法，在使用我们的估值时结合了已公布的世界银行贫困员工人数。我们还针对人体测量的预测对比了绝对和相对财富估值的精确性。.1 403 186 个家庭的绝对财富估算中值为人均 2056 国际元（四分位差：723–6103）。依据绝对财富估值确定的贫困家庭比例与世界银行针对每天人均生活费用低于 2.00 美元 (绝对财富估值为对比性研究创造了新机遇，便于我们评估经济资源对健康和人力资本的影响，以及经济变化和不平等问题产生的长期健康后果。.Оценить абсолютное благосостояние семей с использованием данных демографических опросов и опросов о состоянии здоровья.Нами была разработана новая система показателей — оценка абсолютного благосостояния — на основе категории каждой из опрашиваемых семей в соответствии с их материальными ресурсами и предполагаемым характером распределения благосостояния среди опрашиваемых семей. Оценка абсолютного благосостояния семей была рассчитана на основе данных 156 демографических опросов и опросов о состоянии здоровья в 66 странах. Валидация метода проводилась путем сравнения доли семей, охарактеризованных как бедные с использованием нашей оценки, с данными опубликованных отчетов Всемирного банка о численности бедного населения. Кроме того, сравнивалась точность оценок абсолютного и относительного благосостояния для прогнозирования антропометрических показателей.Медианная абсолютная оценка благосостояния в результате исследования 1 403 186 семей составила 2056 международных долларов на человека (межквартильный диапазон: 723–6103). Доля бедных семей, по данным оценки абсолютного благосостояния, сильно коррелировала с оценками Всемирного банка относительно количества населения, живущего менее чем на 2,00 доллара США в день на человека (Абсолютные оценки благосостояния открывают новые возможности для сравнительных исследований, оценивающих воздействие экономических ресурсов на здоровье и человеческий капитал, а также воздействие, которое экономические перемены и неравенство оказывают на здоровье населения в долгосрочной перспективе.

Summary Background Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group., Graphical Abstract, Highlights • Linguistic evolution is dominated by events of concerted evolutionary change • Modeling concerted evolution improves phylogenetic inference and dating • Events of concerted change conform closely to a Poisson process • Our model can be applied to genes, languages, cultures, and technological change, Concerted evolution refers to the same evolutionary change occurring at different sites in a genome. It also occurs in languages when the same sound change occurs in different words. Hruschka et al. report a statistical model that can detect concerted changes and show how it substantially improves our understanding of how languages evolve.

Here, we test Neutral models against the evolution of English word frequency and vocabulary at the corpus scale, as recorded in annual word frequencies from three centuries of English language books. Against these data, we test both static and dynamic predictions of two neutral models, including the relation between corpus size and vocabulary size, frequency distributions, and turnover within those frequency distributions. Although a commonly used Neutral model fails to replicate all these emergent properties at once, we find that modified two-stage Neutral model does replicate the static and dynamic properties of the corpus data. This two-stage model is meant to represent a relatively small corpus of English books, analogous to a ‘canon’, sampled by an exponentially increasing corpus of books among the wider population of authors. More broadly, this model — a smaller neutral model within a larger neutral model — could represent more broadly those situations where mass attention is focused on a small subset of the cultural variants.

Although wealth is consistently found to be an important predictor of health and well-being, there remains debate as to the best way to conceptualize and operationalize wealth. In this article, we focus on the measurement of economic resources, which is one among many forms of wealth. We provide an overview of the process of measuring material wealth, including theoretical and conceptual considerations, a how-to guide based on the most common approach to measurement, and a review of important theoretical and empirical questions that remain to be resolved. Throughout, we emphasize considerations particular to the settings in which anthropologists work, and we include variations on common approaches to measuring material wealth that might be better suited to anthropologists' theoretical questions, methodological approaches, and fieldwork settings.

Background The transition from the home to college is a phase in which emerging adults shift toward more unhealthy eating and physical activity patterns, higher body mass indices, thus increasing risk of overweight/obesity. Currently, little is understood about how changing friendship networks shape weight gain behaviors. This paper describes the recruitment, data collection, and data analytic protocols for the SPARC (Social impact of Physical Activity and nutRition in College) study, a longitudinal examination of the mechanisms by which friends and friendship networks influence nutrition and physical activity behaviors and weight gain in the transition to college life. Methods The SPARC study aims to follow 1450 university freshmen from a large university over an academic year, collecting data on multiple aspects of friends and friendship networks. Integrating multiple types of data related to student lives, ecological momentary assessments (EMAs) are administered via a cell phone application, devilSPARC. EMAs collected in four 1-week periods (a total of 4 EMA waves) are integrated with linked data from web-based surveys and anthropometric measurements conducted at four times points (for a total of eight data collection periods including EMAs, separated by ~1 month). University databases will provide student card data, allowing integration of both time-dated data on food purchasing, use of physical activity venues, and geographical information system (GIS) locations of these activities relative to other students in their social networks. Discussion Findings are intended to guide the development of more effective interventions to enhance behaviors among college students that protect against weight gain during college.

In a recent paper, Beall, Hofer, and Schaller (2016) use observational time series data to test the hypothesis that the 2014 Ebola outbreak influenced the 2014 U.S. Federal Elections. They find substantial associations between online search volume for Ebola and people’s tendency to vote Republican, an effect observed primarily in states with norms favoring Republican candidates. However, the analyses do not deal with the well-known problem of temporal autocorrelation in time series. We show that all variables analyzed exhibit extremely high levels of temporal autocorrelation (i.e. similarity in data-point values across time). After appropriately removing first-order autocorrelation, the observed relationships are attenuated and non-significant. This suggests that either no real associations exist, or that existing data are insufficiently powered to test the proposed hypotheses. We conclude by highlighting other pitfalls of observational data analysis, and draw attention to analytical strategies developed in related disciplines for avoiding these errors.

Background Prior studies have shown that using uterotonics to augment or induce labor before arrival at comprehensive Emergency Obstetric and Neonatal Care (CEmONC) settings (henceforth, “outside uterotonics”) may contribute to perinatal mortality in low- and middle-income countries. We estimate its effect on perinatal mortality in rural Bangladesh. Methods Using hospital records (23986 singleton term births, Jan 1, 2009-Dec 31, 2015) from rural Bangladesh, we use a logistic regression model to estimate the increased risk of perinatal death from uterotonics administered outside a CEmONC facility. Results Among term births (≥37 weeks gestation), the risk of perinatal death adjusted for key confounders is significantly increased among women reporting uterotonic use outside of CEmONC (OR = 3 · 0, 95 % CI = 2 · 4,3 · 7). This increased risk is particularly high for fresh stillbirths (OR = 4 · 0, 95 % CI = 3 · 0,5 · 3) and intrapartum-related causes of early neonatal deaths (birth asphyxia) (OR = 3 · 1, 95 % CI = 2 · 2,4 · 5). Conclusions In this sample, outside uterotonic use was associated with substantially increased risk of fresh stillbirths, deaths due to birth asphyxia, and all perinatal deaths. In settings of high uterotonic use outside of controlled settings, substantial improvement in both stillbirth and early neonatal mortality may be made by reducing such use. Electronic supplementary material The online version of this article (doi:10.1186/s12978-016-0241-x) contains supplementary material, which is available to authorized users.

BackgroundPost-conflict mental health studies in low-income countries have lacked pre-conflict data to evaluate changes in psychiatric morbidity resulting from political violence.AimsThis prospective study compares mental health before and after exposure to direct political violence during the People's War in Nepal.MethodAn adult cohort completed the Beck Depression Inventory and Beck Anxiety Inventory in 2000 prior to conflict violence in their community and in 2007 after the war.ResultsOf the original 316 participants, 298 (94%) participated in the post-conflict assessment. Depression increased from 30.9 to 40.6%. Anxiety increased from 26.2 to 47.7%. Post-conflict post-traumatic stress disorder (PTSD) was 14.1%. Controlling for ageing, the depression increase was not significant. The anxiety increase showed a dose–response association with conflict exposure when controlling for ageing and daily stressors. No demographic group displayed unique vulnerability or resilience to the effects of conflict exposure.ConclusionsConflict exposure should be considered in the context of other types of psychiatric risk factors. Conflict exposure predicted increases in anxiety whereas socioeconomic factors and non-conflict stressful life events were the major predictors of depression. Research and interventions in postconflict settings therefore should consider differential trajectories for depression v. anxiety and the importance of addressing chronic social problems ranging from poverty to gender and ethnic/caste discrimination.

Background Social relationships have been proposed as a significant factor shaping obesity risk. The first year of college, a period of major social, behavioral, and weight changes, provides a context well-suited to tracking longitudinally the impact of shifting friendships on weight outcomes. This study sought to identify social mechanisms impacting BMI change among emerging adults. Methods An analytic sample of 276 college students (71.0% female, 52.2% non-White) provided repeated reports of relationships and BMI was measured up to four times during 2015–2016. Stochastic actor-oriented models were used to examine change in BMI through social influence and change in friendships over time, controlling for sex and race/ethnicity. Results At baseline, mean BMI was 24.2±4.5 kg/m2. Overall, mean BMI increased over time; individual decreases in BMI were uncommon. There was a selection effect of BMI: participants with BMIs between 22 and 26 kg/m2 were most likely to be nominated as a friend. While participants did not select friends based on BMI similarity, participants who were reported as friends were more likely to experience convergence in BMI over time relative to the BMIs of non-friends (p = 0.015). An increase in BMI (versus stability or a decrease) was more likely for those whose friends had a higher BMI on average compared to participants whose friends had the same or lower BMI (OR = 2.85, 95% CI = 1.22, 6.71). Conclusion Analyses indicated BMI affected friend selection, not through students selecting friends with similar BMI, but rather, by students avoiding friends with more extreme BMI levels.

Cultural competence is often defined as the ability to adhere to a core set of beliefs and practices. In this article, I argue that in many cases competence also involves the creative and occasionally idiosyncratic use of conventional knowledge to meet both personal goals and the specific requirements of local relationships and settings. I illustrate this tension between adopting broadly shared cultural norms and adapting them to local circumstances by examining how U.S. high school students prioritize their expectations of “good friends.” Drawing from cultural consensus approaches in cognitive anthropology, I analyze patterns of agreement among students to show that despite some population-wide sharing, friends share more similar priorities than do nonfriends, and individuals also maintain stable differences in their personal priorities. These patterns of agreement and disagreement support the view that individuals strike a balance between fitting their personal models of friendship to broad cultural norms and accommodating the goals and needs of particular partners. More generally, I argue that competence in a cultural domain (in this case appropriate friendship behaviors) must be examined in relation to the specific contexts of use and the scale of social interaction for that domain. [competence, cultural consensus, friendship, quadratic assignment procedure, adolescence]

Most work on the human fertility transition has focused on declines in mean fertility. However, understanding changes in the variance of reproductive outcomes can be equally important for evolutionary questions about the heritability of fertility, individual determinants of fertility and changing patterns of reproductive skew. Here, we document how variance in completed fertility among women (45–49 years) differs across 200 surveys in 72 low- to middle-income countries where fertility transitions are currently in progress at various stages. Nearly all (91%) of samples exhibit variance consistent with a Poisson process of fertility, which places systematic, and often severe, theoretical upper bounds on the proportion of variance that can be attributed to individual differences. In contrast to the pattern of total variance, these upper bounds increase from high- to mid-fertility samples, then decline again as samples move from mid to low fertility. Notably, the lowest fertility samples often deviate from a Poisson process. This suggests that as populations move to low fertility their reproduction shifts from a rate-based process to a focus on an ideal number of children. We discuss the implications of these findings for predicting completed fertility from individual-level variables.

Contemporary human populations conform to ecogeographic predictions that animals will become more compact in cooler climates and less compact in warmer ones. However, it remains unclear to what extent this pattern reflects plastic responses to current environments or genetic differences among populations. Analyzing anthropometric surveys of 232,684 children and adults from across 80 ethnolinguistic groups in sub-Saharan Africa, Asia and the Americas, we confirm that body surface-to-volume correlates with contemporary temperature at magnitudes found in more latitudinally diverse samples (Adj. R2 = 0.14-0.28). However, far more variation in body surface-to-volume is attributable to genetic population structure (Adj. R2 = 0.50-0.74). Moreover, genetic population structure accounts for nearly all of the observed relationship between contemporary temperature and body surface-to-volume among children and adults. Indeed, after controlling for population structure, contemporary temperature accounts for no more than 4% of the variance in body form in these groups. This effect of genetic affinity on body form is also independent of other ecological variables, such as dominant mode of subsistence and household wealth per capita. These findings suggest that the observed fit of human body surface-to-volume with current climate in this sample reflects relatively large effects of existing genetic population structure of contemporary humans compared to plastic response to current environments.

The evolution of cooperation is a central problem in biology and the social sciences. While theoretical work using the iterated prisoner's dilemma (IPD) has shown that cooperation among non-kin can be sustained among reciprocal strategies (i.e. tit-for-tat), these results are sensitive to errors in strategy execution, cyclical invasions by free riders, and the specific ecology of strategies. Moreover, the IPD assumes that a strategy's probability of playing the PD game with other individuals is independent of the decisions made by others. Here, we remove the assumption of independent pairing by studying a more plausible cooperative dilemma in which players can preferentially interact with a limited set of known partners and also deploy longer-term accounting strategies that can counteract the effects of random errors. We show that cooperative strategies readily emerge and persist in a range of noisy environments, with successful cooperative strategies (henceforth, cliquers) maintaining medium-term memories for partners and low thresholds for acceptable cooperation (i.e. forgiveness). The success of these strategies relies on their cliquishness-a propensity to defect with strangers if they already have an adequate number of partners. Notably, this combination of medium-term accounting, forgiveness, and cliquishness fits with empirical studies of friendship and other long-term relationships among humans.

Psychological anthropology has a long history of integrative, crossdisciplinary research within the social sciences. This holistic tradition has substantially contributed to understanding the relationships between individuals and their cultural environment and to developing more sophisticated models of human variation within and between cultures. Whereas these contributions have generally arisen from conversations between psychology and anthropology, research integrating biological and cultural anthropology has become an increasingly established part of other anthropological subfields, such as medical (Armelagos et al. 1992; Brown et al. 1998; Leatherman 1996; Oths 1998) and biological anthropology (Bogin 1997; Goodman and Leatherman 1998a). This special issue continues psychological anthropology's commitment to holistic inquiry by examining how dialogues between biological and cultural perspectives can generate new insights when applied to key questions in psychological anthropology. The articles in this volume tackle various issues including the effect of cultural consonance on well-being in Brazil, the biocultural roots of addiction among Colombian youth, the social and psychological factors implicated in becoming a Candomble medium, the process of coping with political-ecological inequality in Peru, and the biocultural pathways to somatization and suffering in Nepal. Not surprisingly, the research presented here has direct links to the biocultural

Material wealth is a key factor shaping human development and well-being. Every year, hundreds of studies in social science and policy fields assess material wealth in low- and middle-income countries assuming that there is a single dimension by which households can move from poverty to prosperity. However, a one-dimensional model may miss important kinds of prosperity, particularly in countries where traditional subsistence-based livelihoods coexist with modern cash economies. Using multiple correspondence analysis to analyze representative household data from six countries—Nepal, Bangladesh, Ethiopia, Kenya, Tanzania and Guatemala—across three world regions, we identify a number of independent dimension of wealth, each with a clear link to locally relevant pathways to success in cash and agricultural economies. In all cases, the first dimension identified by this approach replicates standard one-dimensional estimates and captures success in cash economies. The novel dimensions we identify reflect success in different agricultural sectors and are independently associated with key benchmarks of food security and human growth, such as adult body mass index and child height. The multidimensional models of wealth we describe here provide new opportunities for examining the causes and consequences of wealth inequality that go beyond success in cash economies, for tracing the emergence of hybrid pathways to prosperity, and for assessing how these different pathways to economic success carry different health risks and social opportunities.

Much research has established reliable cross-population differences in motivations to invest in one’s in-group. We compare two current historical-evolutionary hypotheses for this variation based on (1) effective large-scale institutions and (2) pathogen threats by analyzing cross-national differences (N = 122) in in-group preferences measured in three ways. We find that the effectiveness of government institutions correlates with favoring in-group members, even when controlling for pathogen stress and world region, assessing reverse causality, and providing a check on endogeneity with an instrumental variable analysis. Conversely, pathogen stress shows inconsistent associations with in-group favoritism when controlling for government effectiveness. Moreover, pathogen stress shows little to no association with in-group favoritism within major world regions whereas government effectiveness does. These results suggest that variation in in-group preferences across contemporary nation-states is more consistent with a generalized response to institutions that meet basic needs rather than an evolved response dedicated to pathogens.

Human populations differ reliably in the degree to which people favor family, friends and community members over strangers and outsiders. In the last decade, researchers have begun to propose several economic and evolutionary hypotheses for these cross-population differences in parochialism. In this paper, we outline major current theories and review recent attempts to test them. We also discuss the key methodological challenges in assessing these diverse economic and evolutionary theories for cross-population differences in parochialism.

Background Antenatal Care (ANC) during pregnancy can play an important role in the uptake of evidence-based services vital to the health of women and their infants. Studies report positive effects of ANC on use of facility-based delivery and perinatal mortality. However, most existing studies are limited to cross-sectional surveys with long recall periods, and generally do not include population-based samples. Methods This study was conducted within the Health and Demographic Surveillance System (HDSS) of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) in Matlab, Bangladesh. The HDSS area is divided into an icddr,b service area (SA) where women and children receive care from icddr,b health facilities, and a government SA where people receive care from government facilities. In 2007, a new Maternal, Neonatal, and Child Health (MNCH) program was initiated in the icddr,b SA that strengthened the ongoing maternal and child health services including ANC. We estimated the association of ANC with facility delivery and perinatal mortality using prospectively collected data from 2005 to 2009. Using a before-after study design, we also determined the role of ANC services on reduction of perinatal mortality between the periods before (2005 – 2006) and after (2008–2009) implementation of the MNCH program. Results Antenatal care visits were associated with increased facility-based delivery in the icddr,b and government SAs. In the icddr,b SA, the adjusted odds of perinatal mortality was about 2-times higher (odds ratio (OR) 1.91; 95% confidence intervals (CI): 1.50, 2.42) among women who received ≤1 ANC compared to women who received ≥3 ANC visits. No such association was observed in the government SA. Controlling for ANC visits substantially reduced the observed effect of the intervention on perinatal mortality (OR 0.64; 95% CI: 0.52, 0.78) to non-significance (OR 0.81; 95% CI: 0.65, 1.01), when comparing cohorts before and after the MNCH program initiation (Sobel test of mediation P < 0.001). Conclusions ANC visits are associated with increased uptake of facility-based delivery and improved perinatal survival in the icddr,b SA. Further testing of the icddr,b approach to simultaneously improving quality of ANC and facility delivery care is needed in the existing health system in Bangladesh and in other low-income countries to maximize health benefits to mothers and newborns.

Background Improving perinatal health is the key to achieving the Millennium Development Goal for child survival. Recently, several reviews suggest that scaling up available effective perinatal interventions in an integrated approach can substantially reduce the stillbirth and neonatal death rates worldwide. We evaluated the effect of packaged interventions given in pregnancy, delivery and post-partum periods through integration of community- and facility-based services on perinatal mortality. Methods This study took advantage of an ongoing health and demographic surveillance system (HDSS) and a new Maternal, Neonatal and Child Health (MNCH) Project initiated in 2007 in Matlab, Bangladesh in half (intervention area) of the HDSS area. In the other half, women received usual care through the government health system (comparison area). The MNCH Project strengthened ongoing maternal and child health services as well as added new services. The intervention followed a continuum of care model for pregnancy, intrapartum, and post-natal periods by improving established links between community- and facility-based services. With a separate pre-post samples design, we compared the perinatal mortality rates between two periods--before (2005-2006) and after (2008-2009) implementation of MNCH interventions. We also evaluated the difference-of-differences in perinatal mortality between intervention and comparison areas. Results Antenatal coverage, facility delivery and cesarean section rates were significantly higher in the post- intervention period in comparison with the period before intervention. In the intervention area, the odds of perinatal mortality decreased by 36% between the pre-intervention and post-intervention periods (odds ratio: 0.64; 95% confidence intervals: 0.52-0.78). The reduction in the intervention area was also significant relative to the reduction in the comparison area (OR 0.73, 95% CI: 0.56-0.95; P = 0.018). Conclusion The continuum of care approach provided through the integration of service delivery modes decreased the perinatal mortality rate within a short period of time. Further testing of this model is warranted within the government health system in Bangladesh and other low-income countries.

This paper examines the association of women’s social networks with the use of skilled birth attendants in uncomplicated pregnancy and childbirth in Matlab, Bangladesh. The Network-Episode Model was applied to determine if network structure variables (density/kinship homogeneity/strength of ties) together with network content (endorsement for or against a particular type of birth attendant) explain the type of birth attendant used by women above and beyond the variance explained by women’s individual attributes. Data were collected by interviewing a representative sample of 246 women, 18–45 years of age, using survey and social network methods between October and December 2008. Logistic regression models were used to examine the associations. Results suggest that the structural properties of networks did not add to explanatory value but instead network content or the perceived advice of network members add significantly to the explanation of variation in service use. Testing aggregate network variables at the individual level extends the ability of the individual profile matrix to explain outcomes. Community health education and mobilization interventions attempting to increase demand for skilled attendants need to reflect the centrality of kinship networks to women in Bangladesh and the likelihood of women to heed the advice of their network of advisors with regard to place of birth.

Objectives. We aimed to test the hypothesized role of shared body size norms in the social contagion of body size and obesity. Methods. Using data collected in 2009 from 101 women and 812 of their social ties in Phoenix, Arizona, we assessed the indirect effect of social norms on shared body mass index (BMI) measured in 3 different ways. Results. We confirmed Christakis and Fowler's basic finding that BMI and obesity do indeed cluster socially, but we found that body size norms accounted for only a small portion of this effect (at most 20%) and only via 1 of the 3 pathways. Conclusions. If shared social norms play only a minor role in the social contagion of obesity, interventions targeted at changing ideas about appropriate BMIs or body sizes may be less useful than those working more directly with behaviors, for example, by changing eating habits or transforming opportunities for and constraints on dietary intake.

Postpartum hemorrhage (PPH) is the leading cause of maternal death and disability worldwide. Recognition depends on subjective visual quantification. This study sought to assess and compare the thresholds for excessive postpartum blood loss reported by skilled birth attendants (SBA), traditional birth attendants (TBA), and laywomen in Matlab, Bangladesh.Data from six questions asking about excessive blood loss in the postpartum period were analyzed using analysis of variance (ANOVA), Hochberg test, Kruskal-Wallis and standard descriptive statistics.Thresholds for excessive blood loss estimated by laywomen and TBAs exceed biomedical standards for PPH. Skilled birth attendant reports are consistent with the definition of severe acute PPH.Further research on locally validated blood collection devices, in birth kits, for diagnostic aid or referral indication is needed. Areas where coverage and uptake of skilled birth attendance are low should be targeted due to the number of home births attended by TBAs and laywomen in such settings.A comparison of excessive postpartum blood loss estimates among skilled birth attendants, traditional birth attendants and laywomen in Matlab, Bangladesh.

In the aftermath of a decade-long Maoist civil war in Nepal and the recent relocation of thousands of Bhutanese refugees from Nepal to Western countries, there has been rapid growth of mental health and psychosocial support programs, including posttraumatic stress disorder (PTSD) treatment, for Nepalis and ethnic Nepali Bhutanese. This medical anthropology study describes the process of identifying Nepali idioms of distress and local ethnopsychology and ethnophysiology models that promote effective communication about psychological trauma in a manner that minimizes stigma for service users. Psychological trauma is shown to be a multi-faceted concept that has no single linguistic corollary in the Nepali study population. Respondents articulated different categories of psychological trauma idioms in relation to impact upon the heart-mind, brain-mind, body, spirit, and social status, with differences in perceived types of traumatic events, symptom sets, emotion clusters, and vulnerability. Trauma survivors felt blamed for experiencing negative events, which were seen as karma transmitting past life sins or family member sins into personal loss. Some families were reluctant to seek care for psychological trauma because of the stigma of revealing this bad karma. In addition, idioms related to brain-mind dysfunction contributed to stigma while heart-mind distress was a socially acceptable reason for seeking treatment. Different categories of trauma idioms support the need for multidisciplinary treatment with multiple points of service entry.

Much anthropological research and theory concerns how group differences in behavior, subjective experience, and ways of seeing the world (i.e., cultural differences) are created and maintained. Both within and outside the United States, there are dramatic group differences in fertility. In the United States, American Indian groups exhibit some of the highest and earliest fertility. We used ethnographic data as well as structured card-sort and questionnaire data to compare cultural models of childbearing among Cherokee and white youth in Appalachia. The critical difference between Cherokee and white youth was not a modal difference in ideal ages for first childbirth but, rather, the degree of latitude for the timing of having children vis-` a-vis other major life events. Group differences in modal norms are often posited as the critical axis of group distinction. In many cases, group differences in the intrapopulation variability among multiple norms may play a more critical role. (Keywords: American Indian, cross-cultural comparison, cultural models, life course, fertility)

Early recognition can reduce maternal disability and deaths due to postpartum haemorrhage. This study identified cultural theories of postpartum bleeding that may lead to inappropriate recognition and delayed care-seeking. Qualitative and quantitative data obtained through structured interviews with 149 participants living in Matlab, Bangladesh, including women aged 18-49 years, women aged 50+ years, traditional birth attendants (TBAs), and skilled birth attendants (SBAs), were subjected to cultural domain. General consensus existed among the TBAs and lay women regarding signs, causes, and treatments of postpartum bleeding (eigenvalue ratio 5.9, mean competence 0.59, and standard deviation 0.15). Excessive bleeding appeared to be distinguished by flow characteristics, not colour or quantity. Yet, the TBAs and lay women differed significantly from the SBAs in beliefs about normalcy of blood loss, causal role of the retained placenta and malevolent spirits, and care practices critical to survival. Cultural domain analysis captures variation in theories with specificity and representativeness necessary to inform community health intervention.