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Mphamba PN, Chirwa GC, Mazalale J. An evolution of inequality of opportunity in the nutritional outcomes of under-five children in Malawi. SSM Popul Health 2024; 25:101606. [PMID: 38292048 PMCID: PMC10825516 DOI: 10.1016/j.ssmph.2024.101606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 02/01/2024] Open
Abstract
Background Malnutrition among children is a significant public health and development issue, especially in low- and middle-income countries, Malawi inclusive, which contributes to preventable diseases and deaths. Significant socioeconomic disparities persist, which affect access to and equal distribution of basic nutrition. This study analyzed the extent and trends of Inequality of Opportunity (IOP) in the nutritional outcomes of children aged 0-59 months. Methods The study used nationally representative data from the 2006, 2013-14, and 2019-20 Malawi Multiple Indicator Cluster Survey. In terms of method, we examined IOP in stunting, wasting, and underweight indicators, using the Human Opportunity Index and the Dissimilarity Index in 55,723 children. The Shapley-value technique decomposed the relative IOP. Results We find the largest share of circumstance-driven inequality in stunting (8.96 percent), followed by underweight (1.91 percent), and then wasting (0.90 percent). The Shapley-value decomposition results indicate the child's age (29.15 percent for stunting, 12.42 percent for underweight, and 52.36 percent for wasting) and gender (8.28 percent, 18.36 percent and 8.87 percent), wealth (6.36 percent, 22.87 percent and 8.54 percent), and mother's education (6.28 percent, 11.29 percent and 5.51 percent) as the dominant contributors to IOP for all three nutritional outcome indicators; stunting, underweight and wasting, respectively. Conclusion The findings suggest that policies aimed at narrowing the wealth and education inequality gap could help equalize nutrition opportunities for children in Malawi.
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Niclou A, Sarma MS. The now and future of human biology at the extremes: An introduction to the special issue. Am J Hum Biol 2024; 36:e24006. [PMID: 37885124 PMCID: PMC10939965 DOI: 10.1002/ajhb.24006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
OBJECTIVES A hallmark of the human species is our adaptability to a wide range of different ecologies and ecosystems, including some of the most extreme settings. Human biologists have long studied how humans have successfully (and sometimes unsuccessfully) adapted to such extremes, particularly ecological extremes like environments at lower limits of temperature and high altitude. In this special issue, we revisit traditional definitions and explore new conceptions of work in extreme environments. We argue that our definitions of extremes should change with our changing world, and account for extremes unique to the Anthropocene, including environments of inequality and precarity, pandemic landscapes, climate-impacted settings, obesogenic environments, and the environments of human spaceflight. We also explore the future of work at the extremes and provide some suggested guidelines on how human biologists can continue to build and expand on foundational work in this area. CONCLUSION While human biologists have done critical work on groups living in extreme environments, our definitions of humans at the limits continue to change as the world around us also changes. Scholars in this area have a responsibility to re-examine the parameters of extremes to stay at the forefront of scientific exploration and collaboration so human biology, as a discipline, can continue to shape our understanding of adaptability, and thus contribute to the continued thriving of all humans as we endure new climatic, environmental, and societal extremes.
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Affiliation(s)
- Alexandra Niclou
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Mallika S. Sarma
- Johns Hopkins Medicine, Baltimore, Maryland, United States of America
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Fox MM, Hahn-Holbrook J, Sandman CA, Marino JA, Glynn LM, Davis EP. Mothers' prenatal distress accelerates adrenal pubertal development in daughters. Psychoneuroendocrinology 2024; 160:106671. [PMID: 38000239 DOI: 10.1016/j.psyneuen.2023.106671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/11/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023]
Abstract
Human life history schedules vary, partly, because of adaptive, plastic responses to early-life conditions. Little is known about how prenatal conditions relate to puberty timing. We hypothesized that fetal exposure to adversity may induce an adaptive response in offspring maturational tempo. In a longitudinal study of 253 mother-child dyads followed for 15 years, we investigated if fetal exposure to maternal psychological distress related to children's adrenarche and gonadarche schedules, assessed by maternal and child report and by dehydroepiandrosterone sulfate (DHEA-S), testosterone, and estradiol levels. We found fetal exposure to elevated maternal prenatal psychological distress predicted earlier adrenarche and higher DHEA-S levels in girls, especially first-born girls, and that associations remained after covarying indices of postnatal adversity. No associations were observed for boys or for gonadarche in girls. Adrenarche orchestrates the social-behavioral transition from juvenility to adulthood; therefore, significant findings for adrenarche, but not gonadarche, suggest that prenatal maternal distress instigates an adaptive strategy in which daughters have earlier social-behavioral maturation. The stronger effect in first-borns suggests that, in adverse conditions, it is in the mother's adaptive interest for her daughter to hasten social maturation, but not necessarily sexual maturation, because it would prolong the duration of the daughter allomothering younger siblings. We postulate a novel evolutionary framework that human mothers may calibrate the timing of first-born daughters' maturation in a way that optimizes their own reproductive success.
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Affiliation(s)
- Molly M Fox
- Department of Anthropology, University of California, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA 90095, USA.
| | | | - Curt A Sandman
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA, 92868, USA
| | - Jessica A Marino
- Department of Psychology, University of California, Merced, CA, 95343, USA
| | - Laura M Glynn
- Department of Psychology, Chapman University, Orange, CA, 92866, USA
| | - Elysia Poggi Davis
- Department of Psychology, University of Denver, Denver, CO, 80208, USA; Department of Pediatrics, University of California, Irvine, CA, 92868, USA
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Vankayalapati A, Wamwere-Njoroge G, Fujita M. Effects of household composition on infant feeding and mother-infant health in northern Kenya. Am J Hum Biol 2024; 36:e23993. [PMID: 37767929 DOI: 10.1002/ajhb.23993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 08/29/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Households with alloparents, individuals other than the mother who care for an infant, can shift members' roles and affect mother-infant health. AIMS To investigate how household composition relates to infant feeding and infectious disease risk in mother-infant dyads, the team utilized data from breastfeeding dyads (n 208) surveyed during a prolonged drought and food scarcity in northern Kenya. METHODS Households were classified by the presence/absence of potential alloparents, distinguishing non-siblings and siblings of the infant. Regression models for breastfeeding frequency, complementary feeding status, and recent infections (n 83) evaluated these outcomes' associations with household type while accounting for food insecurity, adjusted for infant age, infant sex, and maternal age. RESULTS Household type was unassociated with breastfeeding frequency, but the presence of non-sibling alloparents interacted with food insecurity, predicting increasing breastfeeding frequency as food insecurity intensified among dyads living with non-sibling alloparents. Households with non-sibling alloparents were also inversely associated with complementary feeding but had no association with infection. Households with siblings were inversely associated with (protective against) infant and maternal infection. CONCLUSION Further research is needed to understand the interactive influence of household social and food ecologies on mother-infant diet and health under diverse cultural rules and norms for alloparenting.
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Affiliation(s)
- A Vankayalapati
- Lyman Briggs College, Michigan State University, East Lansing, Michigan, USA
- Biomarker Laboratory for Anthropological Research, Michigan State University, East Lansing, Michigan, USA
| | | | - M Fujita
- Biomarker Laboratory for Anthropological Research, Michigan State University, East Lansing, Michigan, USA
- Department of Anthropology, Michigan State University, East Lansing, Michigan, USA
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5
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Helfrecht C, Wang H, Dira SJ, DeAvila D, Meehan CL. DHEAS and nutritional status among Sidama, Ngandu, and Aka children: Effects of cortisol and implications for adrenarche. Am J Hum Biol 2023:e23881. [PMID: 36802115 DOI: 10.1002/ajhb.23881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/28/2023] [Accepted: 02/05/2023] [Indexed: 02/21/2023] Open
Abstract
OBJECTIVE Adrenarche, the biological event marked by rising production of dehydroepiandrosterone and its sulfate (DHEAS), may represent a sensitive period in child development, with important implications for adolescence and beyond. Nutritional status, particularly BMI and/or adiposity, has long been hypothesized as a factor in DHEAS production but findings are inconsistent, and few studies have examined this among non-industrialized societies. In addition, cortisol has not been included in these models. We here evaluate effects of height- (HAZ), weight- (WAZ), and BMI- (BMIZ) for-age on DHEAS concentrations among Sidama agropastoralist, Ngandu horticulturalist, and Aka hunter-gatherer children. METHODS Heights and weights were collected from 206 children aged 2-18 years old. HAZ, WAZ, and BMIZ were calculated using CDC standards. DHEAS and cortisol assays were used to determine biomarker concentrations in hair. Generalized linear modeling was used to examine effects of nutritional status on DHEAS concentrations, as well as cortisol, controlling for age, sex, and population. RESULTS Despite the prevalence of low HAZ and WAZ scores, the majority (77%) of children had BMI z-scores >-2.0 SD. Nutritional status has no significant effect on DHEAS concentrations, controlling for age, sex, and population. Cortisol, however, is a significant predictor of DHEAS concentrations. CONCLUSIONS Our findings do not support a relationship between nutritional status and DHEAS. Instead, results suggest an important role for stress and ecology in DHEAS concentrations across childhood. Specifically, effects of environment via cortisol may be influential to patterning of DHEAS. Future work should investigate local ecological stressors and their relationship to adrenarche.
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Affiliation(s)
- Courtney Helfrecht
- Department of Anthropology, University of Alabama, Tuscaloosa, Alabama, USA
| | - Hui Wang
- Institute for Rural Health Research, University of Alabama, Tuscaloosa, Alabama, USA
| | - Samuel J Dira
- Department of Anthropology, Hawassa University, Hawassa, Ethiopia
| | - David DeAvila
- Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman, Washington, USA
| | - Courtney L Meehan
- Department of Anthropology, Washington State University, Pullman, Washington, USA
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Syme KL, Hagen EH. Bargaining and interdependence: Common parent‐offspring conflict resolution strategies among Chon Chuuk and their implications for suicidal behavior. AMERICAN ANTHROPOLOGIST 2023. [DOI: 10.1111/aman.13821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Kristen L. Syme
- Department of Anthropology Washington State University, Washington Vancouver USA
- Department of Experimental and Applied Psychology Vrije Universiteit Amsterdam Amsterdam the Netherlands
- Institute of Security and Global Affairs Leiden University The Hague Netherlands
| | - Edward H. Hagen
- Department of Anthropology Washington State University, Washington Vancouver USA
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Islam MM, Khan MN. Early childhood development and its association with maternal parity. Child Care Health Dev 2023; 49:80-89. [PMID: 35384014 PMCID: PMC10084392 DOI: 10.1111/cch.13011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 03/18/2022] [Accepted: 03/23/2022] [Indexed: 12/16/2022]
Abstract
BACKGROUND Maternal parity, which is usually measured as the number of children born to a mother, has a substantial impact on the social and environmental factors around children and their development. This paper estimates the Early Childhood Development Index (ECDI) of 3- and 4-year-old children in Bangladesh and examines the relationship between maternal parity and early childhood development. METHODS The study analysed nationally representative data from the Bangladesh Multiple Indicator Cluster Survey 2019. The dataset had 9453 children aged from 36 to 59 months. The ECDI was computed following the UNICEF's approach involving psychometric computation of four domains of development: physical, literacy-numeracy, learning and social-emotional. Since the dataset has a hierarchical structure, we used multilevel logistic regression. RESULTS A quarter (25%) of the children were not on track in their early childhood development. Seventy-one percent were not developmentally on track in the literacy-numeracy domain, 27% were not in the social-emotional and smaller percentages were not in learning (9%) and physical (1%) domains. There was a significant negative association between maternal parity and ECDI (adjusted odds ratio [AOR] 0.95; 95% CI: 0.91-0.99). Attendance at early childhood education programmes was significantly associated with early childhood development (AOR 1.73; 95% CI: 1.47-2.03). Also, female children, those who were not stunted, located in rural areas, received parental stimulation activities, lived in relatively wealthy households or had mothers who had received secondary or further education were more likely than others to be on track of early childhood development. CONCLUSIONS Early childhood development is negatively correlated with maternal parity. The literacy-numeracy domain constitutes the major developmental delay. Programmes for parental awareness should be widely expanded.
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Affiliation(s)
- M Mofizul Islam
- Department of Public Health, La Trobe University, Melbourne, Victoria
| | - Md Nuruzzaman Khan
- Department of Population Sciences, Jatiya Kabi Kazi Nazrul Islam University, Mymensingh, Bangladesh
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Jang H, Janmaat KRL, Kandza V, Boyette AH. Girls in early childhood increase food returns of nursing women during subsistence activities of the BaYaka in the Republic of Congo. Proc Biol Sci 2022; 289:20221407. [PMID: 36382518 PMCID: PMC9667358 DOI: 10.1098/rspb.2022.1407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Nursing mothers face an energetic trade-off between infant care and work. Under pooled energy budgets, this trade-off can be reduced by assistance in food acquisition and infant care tasks from non-maternal carers. Across cultures, children also often provide infant care. Yet the question of who helps nursing mothers during foraging has been understudied, especially the role of children. Using focal follow data from 140 subsistence expeditions by BaYaka women in the Republic of Congo, we investigated how potential support from carers increased mothers' foraging productivity. We found that the number of girls in early childhood (ages 4–7 years) in subsistence groups increased food returns of nursing women with infants (kcal collected per minute). This effect was stronger than that of other adult women, and older girls in middle childhood (ages 8–13 years) and adolescence (ages 14–19 years). Child helpers were not necessarily genetically related to nursing women. Our results suggest that it is young girls who provide infant care while nursing mothers are acquiring food—by holding, monitoring and playing with infants—and, thus, that they also contribute to the energy pool of the community during women's subsistence activities. Our study highlights the critical role of children as carers from early childhood.
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Affiliation(s)
- Haneul Jang
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Karline R. L. Janmaat
- Department of Evolutionary and Population Biology, Institute of Biodiversity and Ecosystem Dynamics, Faculty of Science, University of Amsterdam, 94248 Amsterdam, The Netherlands
- Department of Cognitive Psychology, Faculty of Social and Behavioral Sciences, Leiden University, 2333 Leiden, The Netherlands
| | - Vidrige Kandza
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Adam H. Boyette
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
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9
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Gall B, Wang H, Dira SJ, Helfrecht C. Effects of Family Demographics and Household Economics on Sidama Children's Nutritional Status. HUMAN NATURE (HAWTHORNE, N.Y.) 2022; 33:304-328. [PMID: 36370328 DOI: 10.1007/s12110-022-09432-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/15/2022] [Indexed: 11/14/2022]
Abstract
Weight- (WAZ), height- (HAZ), and BMI-for-age (BMIZ) are frequently used to assess malnutrition among children. These measures represent different categories of risk and are usually hypothesized to be affected by distinct factors, despite their inherent relatedness. Life history theory suggests weight should be sacrificed before height, indicating a demonstrable relationship among them. Here we evaluate impact of family composition and household economics on these measures of nutritional status and explore the role of WAZ as a factor in HAZ. Anthropometrics, family demographics, and measures of household economy were collected from Sidama agropastoralist children in a peri-urban village in southwestern Ethiopia (n = 157; 79 girls). Just over half of the sample (50.9%) had z-scores of - 2SD or below on at least one measure, indicating an elevated risk of morbidity/mortality; 30% were at or below - 2SD on two or more measures. We used hierarchical linear regression with random intercept analysis to model WAZ and HAZ. Siblings and crop sales significantly decrease WAZ while electricity, agriculture, and polygyny improve z-scores; however, an interaction between polygyny and siblings indicates negative effects of siblings in polygynous families and positive effects in nonpolygynous ones (adj. R2 = 66.5%). For HAZ, agriculture and electricity are positively associated with z-scores whereas siblings have a negative effect; the interaction term again indicates that effects of siblings vary in polygynous and nonpolygynous families (adj. R2 = 74.2%). A mediation model exploring the role of weight in height outcomes suggests not only that WAZ has direct effects on HAZ but also that effects of electricity and agriculture on HAZ are partially mediated by WAZ. Our findings indicate that WAZ and HAZ are primarily affected by shared variables, but effects of siblings vary by polygyny status. Long-term outcomes (HAZ) among Sidama children would likely benefit from interventions focused on stabilizing WAZ across family members.
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Affiliation(s)
- Baili Gall
- Department of Anthropology, University of Alabama, Tuscaloosa, AL, USA
| | - Hui Wang
- University of Alabama, Institute for Rural Health Research, Tuscaloosa, AL, USA
| | - Samuel J Dira
- Department of Anthropology, Hawassa University, Hawassa, Ethiopia
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10
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Fox M, Wiley KS. How a pregnant woman's relationships with her siblings relate to her mental health: a prenatal allocare perspective. Evol Med Public Health 2021; 10:1-20. [PMID: 35154777 PMCID: PMC8830312 DOI: 10.1093/emph/eoab044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In cooperatively breeding species, individuals may promote their inclusive fitness through allomothering. Humans exhibit some features of cooperative breeding, and previous studies have focused on allomothering by grandparents and juvenile siblings in the postnatal period. We hypothesize that a pregnant woman's relationships with her siblings (offspring's maternal aunts and uncles) are beneficial for maternal affect in ways that can enhance the siblings' inclusive fitness. Maternal affect during pregnancy is a salient target of allocare given the detrimental effects of antepartum mood disorders on birth and infant outcomes. METHODOLOGY We test our hypotheses in a cohort of pregnant Latina women in Southern California (N = 201). Predictor variables of interest include number of siblings a participant has, if she has sisters, frequency of seeing siblings, and frequency of communication with siblings. Outcome variables measuring maternal affect include depression, state anxiety, pregnancy-related anxiety and perceived stress. RESULTS Having at least one sister and greater frequency of communication with siblings were associated with fewer depressive symptoms during pregnancy. No significant associations were found between sibling variables and other measures of affect. CONCLUSION AND IMPLICATIONS Results suggest that how frequently you communicate with, and not how often you see, siblings could be protective against risk of antepartum depression. Sibling allomothering could impart effects through social-emotional support rather than instrumental support, as a strategy to benefit the prenatal environment in which future nieces and nephews develop. Allomothering may be particularly important in cultural contexts that value family relationships. Future studies should investigate other communities.
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Affiliation(s)
- Molly Fox
- Department of Anthropology, University of California Los Angeles, Los Angeles, CA, USA,Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, USA,Corresponding author. Department of Anthropology, University of California Los Angeles, 341 Haines Hall, 375 Portola Plaza, Los Angeles, CA, USA. Tel: +1 (310) 206-4589; E-mail:
| | - Kyle S Wiley
- Department of Anthropology, University of California Los Angeles, Los Angeles, CA, USA,Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, USA
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11
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Helfrecht C, Roulette JW, Lane A, Sintayehu B, Meehan CL. Life history and socioecology of infancy. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:619-629. [PMID: 32955732 DOI: 10.1002/ajpa.24145] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/06/2020] [Accepted: 08/18/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Evolution of human maternal investment strategies is hypothesized to be tied to biological constraints and environmental cues. It is likely, however, that the socioecological context in which mothers' decisions are made is equally important. Yet, a lack of studies examining maternal investment from a cross-cultural, holistic approach has hindered our ability to investigate the evolution of maternal investment strategies. Here, we take a systems-level approach to study how human life history characteristics, environments, and socioecology influence maternal investment in their children. MATERIALS AND METHODS We test how infant age and sex, maternal age, parity, and child loss, and the composition of a child's cooperative breeding network are associated with maternal investment across three small-scale (hunter-gatherer, horticultural, and agropastoral), sub-Saharan populations (N = 212). Naturalistic behavioral observations also enable us to illustrate the breadth and depth of the human cooperative breeding system. RESULTS Results indicate that infant age, maternal age and parity, and an infant's cooperative childcare network are significantly associated with maternal investment, controlling for population. We also find that human allomaternal care is conducted by a range of caregivers, occupying different relational, sex, and age categories. Moreover, investment by allomothers is widely distributed. DISCUSSION Our findings illustrate the social context in which children are reared in contemporary small-scale populations, and in which they were likely reared throughout our evolutionary history. The diversity of the caregiving network, coupled with life history characteristics, is predictive of maternal investment strategies, demonstrating the importance of cooperation in the evolution of human ontogeny.
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Affiliation(s)
- Courtney Helfrecht
- Department of Anthropology, University of Alabama, Tuscaloosa, Alabama, USA
| | - Jennifer W Roulette
- Department of Anthropology, San Diego State University, San Diego, California, USA
| | - Avery Lane
- Department of Anthropology, Washington State University, Pullman, Washington, USA
| | - Birhanu Sintayehu
- Department of Educational Planning and Management, College of Education and Behavioral Sciences, Haramaya University, Dire Dawa, Ethiopia
| | - Courtney L Meehan
- Department of Anthropology, Washington State University, Pullman, Washington, USA
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12
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Page AE, Thomas MG, Smith D, Dyble M, Viguier S, Chaudhary N, Salali GD, Thompson J, Mace R, Migliano AB. Testing adaptive hypotheses of alloparenting in Agta foragers. Nat Hum Behav 2019; 3:1154-1163. [PMID: 31406338 PMCID: PMC6858278 DOI: 10.1038/s41562-019-0679-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 07/05/2019] [Indexed: 11/29/2022]
Abstract
Human children are frequently cared for by non-parental caregivers (alloparents), yet few studies have conducted systematic alternative hypothesis tests of why alloparents help. Here we explore whether predictions from kin selection, reciprocity, learning-to-mother and costly signalling hypotheses explain non-parental childcare among Agta hunter-gatherers from the Philippines. To test these hypotheses, we used high-resolution proximity data from 1,701 child-alloparent dyads. Our results indicated that reciprocity and relatedness were positively associated with the number of interactions with a child (our proxy for childcare). Need appeared more influential in close kin, suggesting indirect benefits, while reciprocity proved to be a stronger influence in non-kin, pointing to direct benefits. However, despite shared genes, close and distant kin interactions were also contingent on reciprocity. Compared with other apes, humans are unique in rapidly producing energetically demanding offspring. Our results suggest that the support that mothers require is met through support based on kinship and reciprocity.
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Affiliation(s)
- Abigail E Page
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK.
- Department of Anthropology, University College London, London, UK.
| | - Matthew G Thomas
- Department of Anthropology, University College London, London, UK
| | - Daniel Smith
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Mark Dyble
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Sylvain Viguier
- Department of Anthropology, University College London, London, UK
| | - Nikhil Chaudhary
- Department of Archaeology, University of Cambridge, Cambridge, UK
| | - Gul Deniz Salali
- Department of Anthropology, University College London, London, UK
| | - James Thompson
- Department of Anthropology, University College London, London, UK
| | - Ruth Mace
- Department of Anthropology, University College London, London, UK
| | - Andrea B Migliano
- Department of Anthropology, University of Zurich, Zurich, Switzerland
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Rosenbaum S, Gettler LT. With a little help from her friends (and family) part I: the ecology and evolution of non-maternal care in mammals. Physiol Behav 2019; 193:1-11. [PMID: 29933836 DOI: 10.1016/j.physbeh.2017.12.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 11/27/2017] [Accepted: 12/20/2017] [Indexed: 10/28/2022]
Abstract
In the class Mammalia, most young are cared for exclusively by their mothers. In species where mothers receive help, however, non-maternal caregivers may play a crucial role in development and life history trajectories. In turn, recipients of such care may have important impacts on caregivers of all types. In Part I of this overview, we briefly review the evolutionary barriers to widespread non-maternal care in mammals, and explain why the exceptions are of particular theoretical importance. We also summarize the current understanding of the selective forces leading to non-maternal care, and the taxa and types of caretakers amongst which it occurs. Finally, we argue for a fresh look at the categorization schemes that have traditionally been used to separate various types of mammalian non-maternal caregivers. This two-part introduction is aimed at scientists from multiple disciplines who study diverse organismal systems. It draws from the social and biological sciences literatures to provide an overview of this special issue of Physiology and Behavior's suite of methodological offerings and theoretical underpinnings.
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Affiliation(s)
- Stacy Rosenbaum
- Department of Anthropology, Northwestern University, Evanston, IL, United States; Davee Center for Epidemiology and Endocrinology, Lincoln Park Zoo, Chicago, IL, United States.
| | - Lee T Gettler
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, United States; The Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
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Kracht CL, Sisson SB. Sibling influence on children's objectively measured physical activity: a meta-analysis and systematic review. BMJ Open Sport Exerc Med 2018; 4:e000405. [PMID: 30364499 PMCID: PMC6196974 DOI: 10.1136/bmjsem-2018-000405] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2018] [Indexed: 12/26/2022] Open
Abstract
Abstract Children without siblings (only children) have higher rates of obesity than children with siblings. Childhood obesity may be prevented by minimising sedentary behaviour and accumulating sufficient physical activity in young children. A growing number of articles have examined the influence of siblings on physical activity and sedentary behaviour, yet these articles have not been synthesised. Objective To synthesise literature and describe the influence of siblings on objectively measured physical activity and sedentary behaviour of children (ages 2–18 years). Design Outcomes were analysed in a systematic review and meta-analysis. Data sources PubMed, EMBASE, Web of Science and Medline OVID were searched for articles related to siblings, physical activity, sedentary behaviour and obesity outcomes from 1947 to March 2018. Eligibility criteria Articles that evaluated sibling status on physical activity objectively measured by accelerometer or pedometer were included. Results Nineteen articles, representing 17 independent datasets, were included in the review. Nine were included in the quantitative analysis. Pooled data from nine articles indicated children with siblings had higher moderate-to-vigorous physical activity (MVPA) relative to only children, with a potential dose response for higher number of children in household and higher MVPA (Mean Difference=3.13, 95% CI 1.90 to 4.35, p=0.001). Findings were mixed for the influence of siblings on sedentary behaviour and light physical activity. Summary/Conclusion Children with siblings had healthier physical activity patterns, as measured by accelerometer or pedometer, than did only children. Suggested mechanisms include peer modelling, encouraging active transport and sports participation, opportunity for playmate and serving as additional caregivers. Trial registration number CRD42017055463.
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Affiliation(s)
- Chelsea L Kracht
- Department of Nutritional Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Susan B Sisson
- Department of Nutritional Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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15
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Cooper CG, Burns JL, Koster JM, Perri AR, Richards MP. Economic and demographic predictors of dietary variation and nutritional indicators in Nicaragua. Am J Hum Biol 2018; 30:e23125. [PMID: 29637643 DOI: 10.1002/ajhb.23125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 08/11/2017] [Accepted: 03/12/2018] [Indexed: 10/17/2022] Open
Abstract
OBJECTIVES We measured carbon and nitrogen isotopic ratios in a contemporary population, and tested how the isotopic variability relates to measures of socioeconomic status (e.g., household wealth) and anthropometric measures (e.g., standardized height-for-age and weight-for-age z-scores). METHODS Hair samples from individuals living in the Bosawas Biosphere Reserve in Nicaragua were analyzed for δ13 C and δ15 N, and these data were examined in relation to individual (e.g., age, sex, anthropometrics) and household (e.g., household size, wealth) variables. RESULTS We found through mixed-effects modeling that δ13 C and δ15 N varied predictably with individual age and household wealth. δ13 C and δ15 N did not, however, improve models predicting variation in individual anthropometric measures. CONCLUSION These results indicate that, although there is a relationship between diet (δ13 C and δ15 N) and socioeconomic variables, these dietary differences are not the main cause of health differences in this population.
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Affiliation(s)
| | - Jessica L Burns
- The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Jeremy M Koster
- The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Angela R Perri
- The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
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16
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Willführ KP, Johow J, Voland E. When the mother-in-law is just as good-Differential mortality of reproductive females by family network composition. PLoS One 2018; 13:e0193252. [PMID: 29494690 PMCID: PMC5832229 DOI: 10.1371/journal.pone.0193252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 02/07/2018] [Indexed: 11/19/2022] Open
Abstract
Motivated by the cooperative breeding hypothesis, we investigate the effect of having kin on the mortality of reproductive women based on family reconstitutions for the Krummhörn region (East Frisia, Germany, 1720-1874). We rely on a combination of Cox clustered hazard models and hazard models stratified at the family level. In order to study behavior-related effects, we run a series of models in which only kin who lived in the same parish are considered. To investigate structural, non-behavior-related effects, we run a different model series that include all living kin, regardless their spatial proximity. We find that women of reproductive age who had a living mother had a reduced mortality risk. It appears that having living sisters had an ambivalent impact on women's mortality: i.e., depending on the socioeconomic status of the family, the effect of having living sisters ranged between representing a source of competition and representing a source of support. Models which are clustered at the family level suggest that the presence of a living mother-in-law was associated with reduced mortality among her daughters-in-law especially among larger-scale farm families. We interpret this finding as a consequence of augmented consanguineous marriages among individuals of higher social strata. For instance, in first cousin marriages, the mother-in-law could also be a biological aunt. Thus, it appears that among the wealthy elite, the genetic in-law conflict was neutralized to some extent by family solidarity. This result further suggests that the tipping point of the female trade-off between staying with the natal family and leaving the natal family to join an economically well-established in-law family might have been reached very quickly among women living under the socioeconomic conditions of the Krummhörn region.
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Affiliation(s)
- Kai Pierre Willführ
- Max-Planck-Institute for Demographic Research, Rostock, Germany
- Carl von Ossietzky University, Oldenburg, Germany
- * E-mail:
| | | | - Eckart Voland
- Institute for Philosophy, University of Gießen, Germany
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17
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Helfrecht C, Hagen EH, DeAvila D, Bernstein RM, Dira SJ, Meehan CL. DHEAS patterning across childhood in three sub-Saharan populations: Associations with age, sex, ethnicity, and cortisol. Am J Hum Biol 2017; 30. [PMID: 29226590 DOI: 10.1002/ajhb.23090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/05/2017] [Accepted: 11/22/2017] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES Hormones have many roles in human ontogeny, including the timing of life history 'switch points' across development. Limited hormonal data exist from non-Western children, leaving a significant gap in our understanding of the diversity of life history patterning. This cross-sectional study examines dehydroepiandrosterone sulfate (DHEAS) production in relation to age, sex, ethnicity, and cortisol concentrations, as well as average age of adrenarche, among Aka and Ngandu children of the Central African Republic and Sidama children of Ethiopia. METHODS Hair was collected from 480 children (160 per population) aged 3-18 years old. These samples were analyzed for DHEAS and cortisol concentrations using ELISAs. A generalized additive model was used to examine DHEAS patterning in relation to age, sex, cortisol, and ethnicity. The derivative of DHEAS as a function of age was used to identify average age of adrenarche in each population. RESULTS DHEAS patterning in these three populations is distinct from Euro-American patterns of production. In all three groups, the population-level age at adrenarche onset occurs slightly later than Euro-American averages, with both Central African populations experiencing a later onset than the Ethiopian population. CONCLUSIONS DHEAS patterns and age at adrenarche vary across cultures, perhaps indicating adaptive life history responses in diverse eco-cultural environments. Delayed involution of the fetal zone and DHEAS patterning may offer both cognitive protection and immune defense in high-risk, nutritionally-poor environments. Additional research in the majority world is essential to improving our understanding of the diversity of hormonal development and timing of 'switch points' in life history trajectories.
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Affiliation(s)
- Courtney Helfrecht
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
| | - Edward H Hagen
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
| | - David DeAvila
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
| | - Robin M Bernstein
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
| | - Samuel J Dira
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
| | - Courtney L Meehan
- Department of Anthropology, Washington State University, Pullman, Washington P.O. Box 4910 99164-4910
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18
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Lawson DW, Borgerhoff Mulder M. The offspring quantity-quality trade-off and human fertility variation. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150145. [PMID: 27022072 PMCID: PMC4822425 DOI: 10.1098/rstb.2015.0145] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2016] [Indexed: 11/12/2022] Open
Abstract
The idea that trade-offs between offspring quantity and quality shape reproductive behaviour has long been central to economic perspectives on fertility. It also has a parallel and richer theoretical foundation in evolutionary ecology. We review the application of the quantity–quality trade-off concept to human reproduction, emphasizing distinctions between clutch size and lifetime fertility, and the wider set of forces contributing to fertility variation in iteroparous and sexually reproducing species like our own. We then argue that in settings approximating human evolutionary history, several factors limit costly sibling competition. Consequently, while the optimization of quantity–quality trade-offs undoubtedly shaped the evolution of human physiology setting the upper limits of reproduction, we argue it plays a modest role in accounting for socio-ecological and individual variation in fertility. Only upon entering the demographic transition can fertility limitation be clearly interpreted as strategically orientated to advancing offspring quality via increased parental investment per child, with low fertility increasing descendant socio-economic success, although not reproductive success. We conclude that existing economic and evolutionary literature has often overemphasized the centrality of quantity–quality trade-offs to human fertility variation and advocate for the development of more holistic frameworks encompassing alternative life-history trade-offs and the evolved mechanisms guiding their resolution.
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Affiliation(s)
- David W Lawson
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK
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19
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Kramer KL, Veile A, Otárola-Castillo E. Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance. PLoS One 2016; 11:e0150126. [PMID: 26938742 PMCID: PMC4777386 DOI: 10.1371/journal.pone.0150126] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 02/09/2016] [Indexed: 11/18/2022] Open
Abstract
Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children's growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children's monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1) as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2) competition from young siblings will negatively impact child growth during the post weaning period; 3) however because of their economic value, older siblings will have a negligible effect on young children's growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children's growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children's growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance.
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Affiliation(s)
- Karen L. Kramer
- Department of Anthropology, University of Utah, Salt Lake City, Utah 84112, United States of America
| | - Amanda Veile
- Department of Anthropology, Purdue University, West Lafayette, Indiana, United States of America
| | - Erik Otárola-Castillo
- Department of Anthropology, Purdue University, West Lafayette, Indiana, United States of America
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20
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Dawson-Hahn EE, Pak-Gorstein S, Hoopes AJ, Matheson J. Comparison of the Nutritional Status of Overseas Refugee Children with Low Income Children in Washington State. PLoS One 2016; 11:e0147854. [PMID: 26808275 PMCID: PMC4725764 DOI: 10.1371/journal.pone.0147854] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/08/2016] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION The extent that the dual burden of undernutrition and overnutrition affects refugee children before resettlement in the US is not well described. OBJECTIVE To describe the prevalence of wasting, stunting, overweight, and obesity among refugee children ages 0-10 years at their overseas medical screening examination prior to resettlement in Washington State (WA), and to compare the nutritional status of refugee children with that of low-income children in WA. METHODS We analyzed anthropometric measurements of 1047 refugee children ages 0-10 years old to assess their nutritional status at the overseas medical screening examination prior to resettlement in WA from July 2012--June 2014. The prevalence estimates of the nutritional status categories were compared by country of origin. In addition, the nutritional status of refugee children age 0-5 years old were compared to that of low-income children in WA from the Center for Disease Control and Prevention's Pediatric Nutrition Surveillance System. RESULTS A total of 982 children were eligible for the study, with the majority (65%) from Somalia, Iraq and Burma. Overall, nearly one-half of all refugee children had at least one form of malnutrition (44.9%). Refugee children ages 0-10 years were affected by wasting (17.3%), stunting (20.1%), overweight (7.6%) and obesity (5.9%). Among children 0-5 years old, refugee children had a significantly higher prevalence of wasting (14.3% versus 1.9%, p<0.001) and stunting (21.3% versus 5.5%, p<0.001), and a lower prevalence of obesity (6.2% versus 12.9%, p<0.001) than low-income children in WA. CONCLUSION The dual burden of under- and over-nutrition among incoming refugee children as well as their overall difference in prevalence of nutritional status categories compared to low-income children in WA provides evidence for the importance of tailored interventions to address the nutritional needs of refugee children.
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Affiliation(s)
- Elizabeth E. Dawson-Hahn
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Center for Child Health, Behavior and Development, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Suzinne Pak-Gorstein
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Andrea J. Hoopes
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Jasmine Matheson
- Refugee Health Program, Office of Communicable Disease Epidemiology, Washington State Department of Health, Shoreline, Washington, United States of America
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