1
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Smith BH. Mammalian Life History: Weaning and Tooth Emergence in a Seasonal World. BIOLOGY 2024; 13:612. [PMID: 39194550 DOI: 10.3390/biology13080612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 08/06/2024] [Accepted: 08/08/2024] [Indexed: 08/29/2024]
Abstract
The young of toothed mammals must have teeth to reach feeding independence. How tooth eruption integrates with gestation, birth and weaning is examined in a life-history perspective for 71 species of placental mammals. Questions developed from high-quality primate data are then addressed in the total sample. Rather than correlation, comparisons focus on equivalence, sequence, the relation to absolutes (six months, one year), the distribution of error and adaptive extremes. These mammals differ widely at birth, from no teeth to all deciduous teeth emerging, but commonalities appear when infants transit to independent feeding. Weaning follows completion of the deciduous dentition, closest in time to emergence of the first permanent molars and well before second molars emerge. Another layer of meaning appears when developmental age is counted from conception because the total time to produce young feeding independently comes up against seasonal boundaries that are costly to cross for reproductive fitness. Mammals of a vast range of sizes and taxa, from squirrel monkey to moose, hold conception-to-first molars in just under one year. Integrating tooth emergence into life history gives insight into living mammals and builds a framework for interpreting the fossil record.
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Affiliation(s)
- B Holly Smith
- Museum of Anthropological Archaeology, University of Michigan, Ann Arbor, MI 48109, USA
- Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC 20052, USA
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2
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King AG, Rissling T, Cote S, Sicotte P. All together now: Assessing variation in maternal and nonmaternal handling of wild Colobus vellerosus infants. Am J Primatol 2024:e23629. [PMID: 38654439 DOI: 10.1002/ajp.23629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 04/02/2024] [Accepted: 04/14/2024] [Indexed: 04/26/2024]
Abstract
Primatologists have a long-standing interest in the study of maternal care and nonmaternal handling (NH) of infants stemming from recognition that early social relationships can have enduring consequences. Though maternal care and NH often include expression of similar behaviors, they are regularly studied in isolation from each other with nonoverlapping terminology, thereby overlooking possible interplay between them and obfuscating potential developmental ramifications that ensue from trade-offs made between maternal (MH) and NH during infancy. To that end, identifying how MH and NH patterns interact and contribute to the total handling (TH) infants receive is a critical first step. We present durational handling data collected from 25 wild Colobus vellerosus infants from 2016 to 2017 and assess the relationships between TH, MH, and NH. Patterns of social affiliation are shaped in part by surrounding context, and therefore, we also assess whether NH and TH differ in their responsivity to various infant and social group characteristics. Ninety-four percent of observed handling was MH, while just 5.5% was NH. Young infants who received more MH (excluding nursing) also received more NH; there was no relationship between the two in older infants. Infants in larger groups participated in more handling of all types. Additionally, NH time was associated with infant sex and group stability. Non-nursing TH time was associated with group stability and infant cohort size. Though NH variation likely confers social-networking advantage, in this population NH is not a major contributor to TH and would not effectively replace reduced MH. The positive association between MH and NH during early infancy suggests that colobus mothers may play a mediating role in shaping infant socialization. This is a first step in elucidating how different forms of handling relate to one another in wild primates and in identifying the impact of handling on infant socialization.
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Affiliation(s)
- Allyson G King
- Department of Anthropology & Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Tianna Rissling
- Department of Anthropology & Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Susanne Cote
- Department of Anthropology & Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Pascale Sicotte
- Department of Anthropology & Archaeology, University of Calgary, Calgary, Alberta, Canada
- Department of Biology, Concordia University, Montreal, Quebec, Canada
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3
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Pretelli I, Crittenden AN, Dounias E, Friant S, Koster J, Kramer KL, Mangola SM, Saez AM, Lew-Levy S. Child and adolescent foraging: New directions in evolutionary research. Evol Anthropol 2024; 33:e22020. [PMID: 38214699 DOI: 10.1002/evan.22020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 12/01/2023] [Accepted: 12/27/2023] [Indexed: 01/13/2024]
Abstract
Young children and adolescents in subsistence societies forage for a wide range of resources. They often target child-specific foods, they can be very successful foragers, and they share their produce widely within and outside of their nuclear family. At the same time, while foraging, they face risky situations and are exposed to diseases that can influence their immune development. However, children's foraging has largely been explained in light of their future (adult) behavior. Here, we reinterpret findings from human behavioral ecology, evolutionary medicine and cultural evolution to center foraging children's contributions to life history evolution, community resilience and immune development. We highlight the need to foreground immediate alongside delayed benefits and costs of foraging, including inclusive fitness benefits, when discussing children's food production from an evolutionary perspective. We conclude by recommending that researchers carefully consider children's social and ecological context, develop cross-cultural perspectives, and incorporate children's foraging into Indigenous sovereignty discourse.
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Affiliation(s)
- Ilaria Pretelli
- Institute for Advanced Study in Toulouse, Toulouse School of Economics, and University of Toulouse Capitole, Toulouse, France
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Edmond Dounias
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Sagan Friant
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Jeremy Koster
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Karen L Kramer
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Shani M Mangola
- The Law School of Tanzania, Dar es Salaam, Tanzania
- Olanakwe Community Fund, Mang'ola, Tanzania
| | - Almudena Mari Saez
- TransVHIMI Unit, French National Institute for Sustainable Development, IRD, Montpellier, France
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4
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Waynforth D. Alloparental Support and Infant Psychomotor Developmental Delay. HUMAN NATURE (HAWTHORNE, N.Y.) 2024; 35:43-62. [PMID: 38353866 PMCID: PMC11052766 DOI: 10.1007/s12110-024-09468-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/22/2024] [Indexed: 04/29/2024]
Abstract
Receiving social support from community and extended family has been typical for mothers with infants in human societies past and present. In non-industrialised contexts, infants of mothers with extended family support often have better health and higher survival through the vulnerable infant period, and hence shared infant care has a clear fitness benefit. However, there is scant evidence that these benefits continue in industrialised contexts. Better infant health and development with allocare support would indicate continued evolutionary selection for allocare. The research reported here used multiple logistic regression analysis to test whether a lack of family and other social support for mothers was associated with an increased risk of developmental delay in 9-month-old infants in the UK Millennium Cohort (analysis sample size, 15,696 infants). Extended family-based childcare during work hours and more maternal time spent with friends were the most influential kin and social support variables: infants of mothers with kin-based childcare versus all other childcare arrangements had a lower risk of developmental delay (OR = 0.61, 95% CIs: 0.46-0.82). Infants of mothers who spent no time with friends when compared with those who saw friends every day had double the odds of delay. Greater paternal involvement in infant care was associated with a lower odds of developmental delay. In conclusion, shared care of infants and social support for mothers may influence fitness-related traits in industrialised societies rather than being factors that influenced selection only in the past and in societies which retain close kin networks and a strong local community focus.
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Affiliation(s)
- David Waynforth
- School of Medicine, Faculty of Health Sciences, Bond University, Gold Coast, QLD, 4229, Australia.
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5
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Jang H, Ross CT, Boyette AH, Janmaat KR, Kandza V, Redhead D. Women's subsistence networks scaffold cultural transmission among BaYaka foragers in the Congo Basin. SCIENCE ADVANCES 2024; 10:eadj2543. [PMID: 38198536 PMCID: PMC10780863 DOI: 10.1126/sciadv.adj2543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/11/2023] [Indexed: 01/12/2024]
Abstract
In hunter-gatherer societies, women's subsistence activities are crucial for food provisioning and children's social learning but are understudied relative to men's activities. To understand the structure of women's foraging networks, we present 230 days of focal-follow data in a BaYaka community. To analyze these data, we develop a stochastic blockmodel for repeat observations with uneven sampling. We find that women's subsistence networks are characterized by cooperation between kin, gender homophily, and mixed age-group composition. During early childhood, individuals preferentially coforage with adult kin, but those in middle childhood and adolescence are likely to coforage with nonkin peers, providing opportunities for horizontal learning. By quantifying the probability of coforaging ties across age classes and relatedness levels, our findings provide insights into the scope for social learning during women's subsistence activities in a real-world foraging population and provide ground-truth values for key parameters used in formal models of cumulative culture.
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Affiliation(s)
- Haneul Jang
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
- Institute for Advanced Study in Toulouse, Toulouse School of Economics, 1 Esplanade de l'Université, 31080 Toulouse cedex 06, France
| | - Cody T. Ross
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Adam H. Boyette
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Karline R.L. Janmaat
- Department of Evolutionary and Population Biology, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands
- Department of Cognitive Psychology, Faculty of Social and Behavioural Sciences, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, Netherlands
| | - Vidrige Kandza
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Daniel Redhead
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
- Department of Sociology, University of Groningen, Grote Rozenstraat 31, 9712 TG Groningen, Netherlands
- Inter-University Center for Social Science Theory and Methodology, University of Groningen, Groningen, Netherlands
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6
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Obsuth I, Murray AL, Knoll M, Ribeaud D, Eisner M. Teacher-Student Relationships in Childhood as a Protective Factor against Adolescent Delinquency up to Age 17: A Propensity Score Matching Approach. CRIME AND DELINQUENCY 2023; 69:727-755. [PMID: 36960348 PMCID: PMC10026349 DOI: 10.1177/00111287211014153] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this paper we examined the impact of the quality of teacher-student relationships at age 10 on young people's delinquency at ages 13, 15, and 17 utilizing propensity-score matching. The young people were matched based on 105 characteristics, measured at ages 7 to 10. The sample comprised 1483 (49.4% female) adolescents representing around 80 different countries of origin, residing in Zurich, Switzerland. We found that young people who reported a better relationship with their teacher at age 10, engaged in fewer delinquent acts at ages 13, 15, and 17. These findings suggest that when young people perceive a better relationship with their teachers this serves as a protective factor against their engagement in delinquency up to 7 years later.
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Affiliation(s)
- Ingrid Obsuth
- University of Edinburgh, Scotland,
UK
- University of Cambridge, UK
| | | | | | | | - Manuel Eisner
- University of Cambridge, UK
- University of Zurich, Switzerland
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7
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Du J, Huang Y, Bai PP, Zhou L, Myers S, Page AE, Mace R. Post-marital residence patterns and the timing of reproduction: evidence from a matrilineal society. Proc Biol Sci 2023; 290:20230159. [PMID: 36946117 PMCID: PMC10031416 DOI: 10.1098/rspb.2023.0159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/22/2023] [Indexed: 03/23/2023] Open
Abstract
Humans exhibit a broad range of post-marital residence patterns and there is growing recognition that post-marital residence predicts women's reproductive success; however, the nature of the relationship is probably dependent on whether co-resident kin are cooperators or competitors. Here, we explore this relationship in a Tibetan population, where couples practice a mixture of post-marital residence patterns, co-residing in the same village with the wife's parents, the husband's parents or endogamously with both sets of parents. Using detailed demographic data from 17 villages we find that women who live with only their own parents have an earlier age at first birth (AFB) and age at last birth (ALB) than women who live with only their parents-in-law. Women who co-reside with both sets of parents have the earliest AFB and ALB. However, those with co-resident older siblings postponed reproduction, suggestive of competition-related delay. Shifts to earlier reproductive timing were also observed in relation to the imposition of family planning policies, in line with Fisherian expectations. Our study provides evidence of the costs and benefits to women's direct fitness of co-residing with different kin, against a backdrop of adaptive responses to cultural constraints on completed fertility.
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Affiliation(s)
- Juan Du
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, People's Republic of China
| | - Yaming Huang
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, People's Republic of China
| | - Peng-Peng Bai
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, People's Republic of China
| | - Liqiong Zhou
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, People's Republic of China
| | - Sarah Myers
- Department of Anthropology, University College London, London, UK
- BirthRites Independent Max Planck Research Group, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Abigail E. Page
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Ruth Mace
- Department of Anthropology, University College London, London, UK
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8
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Tsutaya T, Mizushima N. Evolutionary biological perspectives on current social issues of breastfeeding and weaning. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023. [PMID: 36815441 DOI: 10.1002/ajpa.24710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 02/24/2023]
Abstract
Breastfeeding and weaning are actively studied from evolutionary, medical, and social research perspectives because of their close association with infant mortality, lifetime health, and human population dynamics. Each discipline benefits from an interdisciplinary exchange of knowledge regarding the bases, processes, and consequences of these phenomena. However, current social issues related to breastfeeding and weaning have received little attention from an evolutionary biology perspective. We address this gap by reviewing current social issues related to human breastfeeding and weaning in an evolutionary framework. This approach helps build a conceptual framework with the goal of better understanding ultimate causes of or influences on these current social issues. The six social issues reviewed here fall into three categories: the spatiotemporal constraints of breastfeeding, abuse of breast milk as valuable material, and mismatch in breastfeeding practices. Some of these issues have an evolutionary basis. We analyze the structure of these social issues and discuss their possible solutions in terms of extension of the trade-off theory in evolutionary biology. Our discussion on the current social issues in breastfeeding and weaning highlights the effectiveness of an approach rooted in evolutionary theory and biological anthropology.
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Affiliation(s)
- Takumi Tsutaya
- Department of Evolutionary Studies of Biosystems, Research Center for Integrative Evolutionary Science, The Graduate University for Advanced Studies, Hayama, Kanagawa, Japan.,Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nozomi Mizushima
- Department of Social System Design, Eikei University of Hiroshima, Naka-ku, Hiroshima, Japan
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9
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Fox SA, Scelza B, Silk J, Kramer KL. New perspectives on the evolution of women's cooperation. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210424. [PMID: 36440567 PMCID: PMC9703265 DOI: 10.1098/rstb.2021.0424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 09/28/2022] [Indexed: 11/29/2022] Open
Abstract
A holistic, evolutionary framework about human cooperation must incorporate information about women's cooperative behaviour. Yet, most empirical research on human cooperation has centered on men's behaviour or been derived from experimental studies conducted in western, industrialized populations. These bodies of data are unlikely to accurately represent human behavioural diversity. To address this gap and provide a more balanced view of human cooperation, this issue presents substantial new data and multi-disciplinary perspectives to document the complexity of women's cooperative behaviour. Research in this issue 1) challenges narratives about universal gender differences in cooperation, 2) reconsiders patrilocality and access to kin as constraints on women's cooperation, 3) reviews evidence for a connection between social support and women's health and 4) examines the phylogenetic roots of female cooperation. Here, we discuss the steps taken in this issue toward a more complete and evidence-based understanding of the role that cooperation plays in women's and girls' lives and in building human sociality. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Stephanie A. Fox
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Brooke Scelza
- Department of Anthropology, UCLA, Los Angeles, CA 90095, USA
| | - Joan Silk
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85281, USA
| | - Karen L. Kramer
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
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10
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Kramer KL. Female cooperation: evolutionary, cross-cultural and ethnographic evidence. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210425. [PMID: 36440565 PMCID: PMC9703230 DOI: 10.1098/rstb.2021.0425] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 08/11/2022] [Indexed: 11/29/2022] Open
Abstract
Women and girls cooperate with each other across many domains and at many scales. However, much of this information is buried in the ethnographic record and has been overlooked in theoretic constructions of the evolution of human sociality and cooperation. The assumed primacy of male bonding, hunting, patrilocality and philopatry has dominated the discussion of cooperation without balanced consideration. A closer look at the ethnographic record reveals that in addition to cooperative childcare and food production, women and girls collectively form coalitions, have their own cooperative political, ceremonial, economic and social institutions, and develop female-based exchange and support networks. The numerous ethnographic examples of female cooperation urge reconsideration of gender stereotypes and the limits of female cooperation. This review brings together theoretic, cross-cultural and cross-lifespan research on female cooperation to present a more even and empirically supported view of female sociality. Following the lead from trends in evolutionary biology and sexual selection theory, the hope going forward is that the focus shifts from rote characterizations of sex differences to highlighting sources of variation and conditions that enhance or constrain female cooperative engagement. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Karen L. Kramer
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
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11
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Seabright E, Alami S, Kraft TS, Davis H, Caldwell AE, Hooper P, McAllister L, Mulville S, Veile A, von Rueden C, Trumble B, Stieglitz J, Gurven M, Kaplan H. Repercussions of patrilocal residence on mothers' social support networks among Tsimane forager-farmers. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210442. [PMID: 36440570 PMCID: PMC9703270 DOI: 10.1098/rstb.2021.0442] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 09/06/2022] [Indexed: 11/29/2022] Open
Abstract
While it is commonly thought that patrilocality is associated with worse outcomes for women and their children due to lower social support, few studies have examined whether the structure of female social networks covaries with post-marital residence. Here, we analyse scan sample data collected among Tsimane forager-farmers. We compare the social groups and activity partners of 181 women residing in the same community as their parents, their husband's parents, both or neither. Relative to women living closer to their in-laws, women living closer to their parents are less likely to be alone or solely in the company of their nuclear family (odds ratio (OR): 0.6, 95% CI: 0.3-0.9), and more likely to be observed with others when engaging in food processing and manufacturing of market or household goods, but not other activities. Women are slightly more likely to receive childcare support from outside the nuclear family when they live closer to their parents (OR = 1.8, 95% CI 0.8-3.9). Their social group size and their children's probability of receiving allocare decrease significantly with distance from their parents, but not their in-laws. Our findings highlight the importance of women's proximity to kin, but also indicate that patrilocality per se is not costly to Tsimane women. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Edmond Seabright
- School of Collective Intelligence, Mohammed 6 Polytechnic University, Ben Guerir 43150, Morocco
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87106, USA
| | - Sarah Alami
- School of Collective Intelligence, Mohammed 6 Polytechnic University, Ben Guerir 43150, Morocco
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Thomas S. Kraft
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
| | - Helen Davis
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 01451, USA
| | - Ann E. Caldwell
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80217, USA
| | - Paul Hooper
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87106, USA
- Economic Science Institute, Chapman University, Orange, CA 92866, USA
| | - Lisa McAllister
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
| | - Sarah Mulville
- Institute of Agriculture, University of Tennessee, Knoxville, TN 37996, USA
| | - Amanda Veile
- Department of Anthropology, Purdue University, West Lafayette, IN, USA
| | | | - Benjamin Trumble
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85287-1701, USA
| | - Jonathan Stieglitz
- Institute for Advanced Study in Toulouse, Toulouse 1 Capitol University, Toulouse 31080, France
| | - Michael Gurven
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Hillard Kaplan
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87106, USA
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12
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Starkweather KE, Reynolds AZ, Zohora F, Alam N. Shodagor women cooperate across domains of work and childcare to solve an adaptive problem. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210433. [PMID: 36440563 PMCID: PMC9703234 DOI: 10.1098/rstb.2021.0433] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/03/2022] [Indexed: 11/29/2022] Open
Abstract
Across human societies, women's economic production and their contributions to childcare are critical in supporting reproductive fitness for themselves, their spouses and children. Yet, the necessity of performing both work and childcare tasks presents women with an adaptive problem in which they must determine how best to allocate their time and energy between these tasks. Women often use cooperative relationships with alloparents to solve this problem, but whether or not women cooperate across different domains (e.g. work and childcare) to access alloparents remains relatively under-explored. Using social network data collected with Shodagor households in Bangladesh, we show that women who need childcare help in order to work draw on cooperative work partners as potential alloparents, and that all women rely heavily on kin, but not reciprocal cooperation for childcare help. These results indicate that Shodagor women strategize to create work and childcare relationships in ways that help solve the adaptive problem they face. We discuss the implications of our results and the example provided by Shodagor women for a broader understanding of women's cooperative relationships, including the importance of socio-ecological circumstances and gendered divisions of labour in shaping women's cooperative strategies. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- K. E. Starkweather
- Department of Anthropology, University of Illinois Chicago, Chicago, IL 60607, USA
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - A. Z. Reynolds
- Department of Anthropology, University of New Mexico, Albuquerque, NM 8731, USA
| | - F. Zohora
- Health Systems and Population Studies Division, ICDDR,B, Dhaka 1212, Bangladesh
| | - N. Alam
- Health Systems and Population Studies Division, ICDDR,B, Dhaka 1212, Bangladesh
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13
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Hackman J, Kramer KL. Kin networks and opportunities for reproductive cooperation and conflict among hunter-gatherers. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210434. [PMID: 36440562 PMCID: PMC9703223 DOI: 10.1098/rstb.2021.0434] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 10/03/2022] [Indexed: 11/29/2022] Open
Abstract
Little is known about the potential for reproductive conflict among hunter-gatherer populations, who are characterized by bilateral kinship ties, flexible residential mobility, and high offspring mortality. To assess the potential for reproductive conflict, we use longitudinal residence and reproductive history data for two bands of South American foragers. Using multilevel logistic regressions (N = 44 women, N = 712 person years), we examine how yearly measures of (i) camp composition, (ii) distribution of female kin and (iii) a woman's position in a female kinship network impact the likelihood of giving birth or experiencing a child's death. We compare conflict models to a demographic model that accounts for the proportion of women giving birth in a given year. Contrary to conflict models, results show that the odds of giving birth increase with the presence of highly related women. However, the odds of experiencing an offspring death are insensitive to the presence of coresident women. Network measures of closeness and centrality in the female kin network also show no significant effect on reproductive outcomes. Furthermore, chances of both births and deaths increase in years when proportionally more women are giving birth. We argue that demographic stochasticity relating to ecological conditions best predicts reproductive outcomes for women. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Joseph Hackman
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
| | - Karen L. Kramer
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
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Page AE, Migliano AB, Dyble M, Major-Smith D, Viguier S, Hassan A. Sedentarization and maternal childcare networks: role of risk, gender and demography. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210435. [PMID: 36440566 PMCID: PMC9703224 DOI: 10.1098/rstb.2021.0435] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 05/26/2022] [Indexed: 11/29/2022] Open
Abstract
Women cooperate over multiple domains and while research from western contexts portrays women's networks as limited in size and breadth, women receive help, particularly with childcare, from a diverse range of individuals (allomothers). Nonetheless, little exploration has occurred into why we see such diversity. Wide maternal childcare networks may be a consequence of a lack of resource accumulation in mobile hunter-gatherers-where instead households rely on risk-pooling in informal insurance networks. By contrast, when households settle and accumulate resources, they are able to retain risk by absorbing losses. Thus, the size and composition of mothers' childcare networks may depend on risk-buffering, as captured by mobile and settled households in the Agta, a Philippine foraging population with diverse lifestyles. Across 78 children, we find that childcare from grandmothers and sisters was higher in settled camps, while childcare from male kin was lower, offering little support for risk-buffering. Nonetheless, girls' workloads were increased in settled camps while grandmothers had fewer dependent children, increasing their availability. These results point to gender-specific changes associated with shifting demographics as camps become larger and more settled. Evidently, women's social networks, rather than being constrained by biology, are responsive to the changing socioecological context. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Abigail E. Page
- Department of Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Andrea B. Migliano
- Department of Anthropology, University of Zürich, Zurich 8006, Switzerland
| | - Mark Dyble
- Department of Anthropology, University College London, London WC1E 6BT, UK
| | - Daniel Major-Smith
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 1TH, UK
| | - Sylvain Viguier
- Department of Anthropology, University College London, London WC1E 6BT, UK
- Graphcore, Lynton House, 7–12 Tavistock Square, London WC1H 9LT, UK
| | - Anushé Hassan
- Department of Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
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15
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Dropout from Mental Health Treatment Among Asylum-Seekers in Israel: A Retrospective Chart Study. J Immigr Minor Health 2022; 25:539-547. [DOI: 10.1007/s10903-022-01427-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2022] [Indexed: 12/12/2022]
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16
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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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17
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(Super-)cultural clustering explains gender differences too. Behav Brain Sci 2022; 45:e156. [PMID: 36098408 DOI: 10.1017/s0140525x21001539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The target paper shows how cultural adaptations to ecological problems can underpin "paradoxical" patterns of phenotypic variation. We argue: (1) Gendered social learning is a cultural adaptation to an ecological problem. (2) In evolutionarily novel environments, this adaptation generates arbitrary-gendered outcomes, leading to the paradoxical case of larger sex differences in more gender equal societies.
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18
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Behringer V, Berghänel A, Deschner T, Lee SM, Fruth B, Hohmann G. Transition to siblinghood causes a substantial and long-lasting increase in urinary cortisol levels in wild bonobos. eLife 2022; 11:77227. [PMID: 36040310 PMCID: PMC9489214 DOI: 10.7554/elife.77227] [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: 01/20/2022] [Accepted: 08/29/2022] [Indexed: 11/26/2022] Open
Abstract
In animals with slow ontogeny and long-term maternal investment, immatures are likely to experience the birth of a younger sibling before reaching maturity. In these species, the birth of a sibling marks a major event in an offspring’s early life as the older siblings experience a decrease in maternal support. The transition to siblinghood (TTS) is often considered to be stressful for the older offspring, but physiological evidence is lacking. To explore the TTS in wild bonobos, we investigated physiological changes in urinary cortisol (stress response), neopterin (cell-mediated immunity), and total triiodothyronine (T3, metabolic rate), as well as changes in behaviors that reflect the mother–offspring relationship. Following a sibling’s birth, urinary cortisol levels of the older offspring increased fivefold, independent of their age, and remained elevated for 7 months. The cortisol level increase was associated with declining neopterin levels; however, T3 levels and behavioral measures did not change. Our results indicate that the TTS is accompanied by elevated cortisol levels and that this change does not coincide with nutritional weaning and attainment of physical independence. Our results suggest that bonobos and humans experience TTS in similar ways and that this developmental event may have emerged in the last common ancestor.
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Affiliation(s)
- Verena Behringer
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Andreas Berghänel
- Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Germany
| | - Tobias Deschner
- Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
| | - Sean M Lee
- Department of Anthropology, George Washington University, Washington, United States
| | - Barbara Fruth
- Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Gottfried Hohmann
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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19
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Mateos A, Zorrilla-Revilla G, Rodríguez J. Let's Play at Digging : How Vigorous Is This Energetic Task for a Young Forager? HUMAN NATURE (HAWTHORNE, N.Y.) 2022; 33:172-195. [PMID: 35666462 PMCID: PMC9250475 DOI: 10.1007/s12110-022-09428-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/22/2022] [Indexed: 11/28/2022]
Abstract
Extractive foraging tasks, such as digging, are broadly practiced among hunter-gatherer populations in different ecological conditions. Despite tuber-gathering tasks being widely practiced by children and adolescents, little research has focused on the physical traits associated with digging ability. Here, we assess how age and energetic expenditure affect the performance of this extractive task. Using an experimental approach, the energetic cost of digging to extract simulated tubers is evaluated in a sample of 40 urban children and adolescents of both sexes to measure the intensity of the physical effort and the influence of several anatomical variables. Digging is a moderately vigorous activity for inexperienced girls and boys from 8 to 14 years old, and it requires significant physical effort depending on strength and body size. However, extracting subterranean resources is a task that may be performed effectively without previous training. Sex-specific and age-specific differences in the net energy expenditure of digging were detected, even though both sexes exhibited similar proficiency levels when performing the task. Our results highlight that both boys and girls spend considerable energy while digging, with differences largely driven by body size and age. Other factors beyond ability and experience, such as strength and body size, may influence the proficiency of juveniles in performing certain physically intensive foraging tasks, such as gathering tubers.
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Affiliation(s)
- Ana Mateos
- National Research Center On Human Evolution (CENIEH), 09002, Burgos, Spain.
| | | | - Jesús Rodríguez
- National Research Center On Human Evolution (CENIEH), 09002, Burgos, Spain
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20
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Veile A, Christopher L, Azcorra H, Dickinson F, Kramer K, Varela‐Silva I. Differences in nutritional status between rural and urban Yucatec Maya children: The importance of early life conditions. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022. [PMCID: PMC9314705 DOI: 10.1002/ajpa.24510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Early‐life conditions shape childhood growth and are affected by urbanization and the nutritional transition. To investigate how early‐life conditions (across the “first” and “second” 1000 days) are associated with rural and urban children's nutritional status, we analyzed anthropometric data from Maya children in Yucatan, Mexico. We collected weight, height and triceps skinfold measures, then computed body mass and fat mass indices (BMI/FMI), in a cross‐sectional sample of 6‐year‐olds (urban n = 72, rural n = 66). Demographic, socioeconomic and early‐life variables (birthweight/mode, rural/urban residence, household crowding) were collected by maternal interview. We statistically analyzed rural‐urban differences in demographic, socioeconomic, early‐life, and anthropometric variables, then created linear mixed models to evaluate associations between early‐life variables and child anthropometric outcomes. Two‐way interactions were tested between early‐life variables and child sex, and between early‐life variables and rural‐urban residence. Results showed that rural children were shorter‐statured, with lower overweight/obesity and cesarean delivery rates, compared to urban children. Household crowding was a negative predictor of anthropometric outcomes; the strongest effect was in boys and in urban children. Birthweight positively predicted anthropometric outcomes, especially weight/BMI. Birth mode was positively (not statistically) associated with any anthropometric outcome. Cesarean delivery was more common in boys than in girls, and predicted increased height in urban boys. In conclusion, urbanization and household crowding were the most powerful predictors of Maya 6‐year‐old anthropometry. The negative effects of crowding may disproportionately affect Maya boys versus girls and urban versus rural children. Early‐life conditions shape Maya children's nutritional status both in the “first” and “second” 1000 days.
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Affiliation(s)
- Amanda Veile
- Department of Anthropology Purdue University West Lafayette Indiana USA
| | | | - Hugo Azcorra
- Centro de Investigaciones Silvio Zavala Universidad Modelo Mérida Mexico
| | - Federico Dickinson
- Departamento de Ecología Humana Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Mérida Mexico
| | - Karen Kramer
- Department of Anthropology University of Utah Salt Lake City Utah USA
| | - Inês Varela‐Silva
- Departamento de Ecología Humana Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Mérida Mexico
- School of Sport, Exercise and Health Sciences Loughborough University Loughborough UK
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21
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Lew-Levy S, Reckin R, Kissler SM, Pretelli I, Boyette AH, Crittenden AN, Hagen RV, Haas R, Kramer KL, Koster J, O'Brien MJ, Sonoda K, Surovell TA, Stieglitz J, Tucker B, Lavi N, Ellis-Davies K, Davis HE. Socioecology shapes child and adolescent time allocation in twelve hunter-gatherer and mixed-subsistence forager societies. Sci Rep 2022; 12:8054. [PMID: 35577896 PMCID: PMC9110336 DOI: 10.1038/s41598-022-12217-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 05/06/2022] [Indexed: 11/09/2022] Open
Abstract
A key issue distinguishing prominent evolutionary models of human life history is whether prolonged childhood evolved to facilitate learning in a skill- and strength-intensive foraging niche requiring high levels of cooperation. Considering the diversity of environments humans inhabit, children's activities should also reflect local social and ecological opportunities and constraints. To better understand our species' developmental plasticity, the present paper compiled a time allocation dataset for children and adolescents from twelve hunter-gatherer and mixed-subsistence forager societies (n = 690; 3-18 years; 52% girls). We investigated how environmental factors, local ecological risk, and men and women's relative energetic contributions were associated with cross-cultural variation in child and adolescent time allocation to childcare, food production, domestic work, and play. Annual precipitation, annual mean temperature, and net primary productivity were not strongly associated with child and adolescent activity budgets. Increased risk of encounters with dangerous animals and dehydration negatively predicted time allocation to childcare and domestic work, but not food production. Gender differences in child and adolescent activity budgets were stronger in societies where men made greater direct contributions to food production than women. We interpret these findings as suggesting that children and their caregivers adjust their activities to facilitate the early acquisition of knowledge which helps children safely cooperate with adults in a range of social and ecological environments. These findings compel us to consider how childhood may have also evolved to facilitate flexible participation in productive activities in early life.
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Affiliation(s)
- Sheina Lew-Levy
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Pl. 6, 04103, Leipzig, Germany.
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Pl. 6, 04103, Leipzig, Germany.
| | - Rachel Reckin
- Department of Archaeology, University of Cambridge, Downing Street, Cambridge, CV2 3DZ, UK
| | - Stephen M Kissler
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA, 02115, USA
| | - Ilaria Pretelli
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Pl. 6, 04103, Leipzig, Germany
| | - Adam H Boyette
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Pl. 6, 04103, Leipzig, Germany
| | - Alyssa N Crittenden
- Department of Anthropology, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy., Las Vegas, NV, 89154, USA
| | - Renée V Hagen
- Department of Anthropology, University of California, Los Angeles, 375 Portola Plaza, Los Angeles, CA, 90095, USA
| | - Randall Haas
- Department of Anthropology, Wayne State University, 656 W. Kirby St., 3037 FAB, Detroit, MI, 48202, USA
| | - Karen L Kramer
- Department of Anthropology, University of Utah, 260 Central Campus Drive, Suite 4553, Salt Lake City, UT, 84112, USA
| | - Jeremy Koster
- Department of Anthropology, University of Cincinnati, 481 Braunstein Hall, PO Box 210380, Cincinnati, OH, 45221-0380, USA
| | - Matthew J O'Brien
- Department of Anthropology, California State University, Chico, 400 W. First St., Chico, CA, 95929-0400, USA
| | - Koji Sonoda
- Faculty of Humanities and Social Sciences, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181, Japan
| | - Todd A Surovell
- Department of Anthropology, University of Wyoming, 12th and Lewis Streets, Laramie, WY, 8207, USA
| | - Jonathan Stieglitz
- Institute for Advanced Study in Toulouse, Université Toulouse 1 Capitole, 1 Esplanade de l'Université, 31080, Toulouse Cedex 06, France
| | - Bram Tucker
- Department of Anthropology, University of Georgia, 250 Baldwin Hall, Athens, GA, 30602, USA
| | - Noa Lavi
- Department of Anthropology, University of Haifa, Abba Khoushy Ave 199, Mount Carmel, 3498838, Haifa, Israel
- Department of Anthropology, University College London, 14 Taviton Street, London, WC1H 0BW, UK
| | - Kate Ellis-Davies
- Department of Psychology, Swansea University, Singleton Park, Sketty, Swansea, SA2 8PP, UK
| | - Helen E Davis
- Department of Human Evolutionary Biology, Harvard, 11 Divinity Avenue, Cambridge, MA, 02138, USA.
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22
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Abstract
Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal, and health implications, as it challenges the predominant view in Western, educated, industrialized, rich, and democratic (WEIRD) societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions.
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Affiliation(s)
- Tobias Grossmann
- Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA
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23
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Fang X, Wang Y, Huang Z. Oxytocin Neurons Are Essential in the Social Transmission of Maternal Behavior. Front Behav Neurosci 2022; 16:847396. [PMID: 35368302 PMCID: PMC8971709 DOI: 10.3389/fnbeh.2022.847396] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 02/08/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Xin Fang
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yongjie Wang
- School of Pharmacy and Department of Neurosurgery, The Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Hangzhou Normal University, Hangzhou, China
- Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Hangzhou Normal University, Hangzhou, China
- Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou, China
| | - Zhihui Huang
- School of Pharmacy and Department of Neurosurgery, The Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Hangzhou Normal University, Hangzhou, China
- Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Hangzhou Normal University, Hangzhou, China
- Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou, China
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24
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Ivey Henry P, Morelli GA. Niche Construction in Hunter-Gatherer Infancy: Growth and Health Trade-Offs Inform Social Agency. EVOLUTIONARY PSYCHOLOGY 2022. [DOI: 10.1007/978-3-030-76000-7_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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25
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KONISHI TATSUKI, YAMAUCHI TARO. The impact of oral contact and alloparenting on infant diarrhea in a hunter-gatherer society in Cameroon. ANTHROPOL SCI 2022. [DOI: 10.1537/ase.210926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- TATSUKI KONISHI
- Graduate School of Health Sciences, Hokkaido University, Sapporo
| | - TARO YAMAUCHI
- Graduate School of Health Sciences, Hokkaido University, Sapporo
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26
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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] [Grants] [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
| | - 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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27
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Padilla-Iglesias C, Kramer KL. The Role of Language in Structuring Social Networks Following Market Integration in a Yucatec Maya Population. Front Psychol 2021; 12:656963. [PMID: 34975603 PMCID: PMC8716436 DOI: 10.3389/fpsyg.2021.656963] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Language is the human universal mode of communication, and is dynamic and constantly in flux accommodating user needs as individuals interface with a changing world. However, we know surprisingly little about how language responds to market integration, a pressing force affecting indigenous communities worldwide today. While models of culture change often emphasize the replacement of one language, trait, or phenomenon with another following socioeconomic transitions, we present a more nuanced framework. We use demographic, economic, linguistic, and social network data from a rural Maya community that spans a 27-year period and the transition to market integration. By adopting this multivariate approach for the acquisition and use of languages, we find that while the number of bilingual speakers has significantly increased over time, bilingualism appears stable rather than transitionary. We provide evidence that when indigenous and majority languages provide complementary social and economic payoffs, both can be maintained. Our results predict the circumstances under which indigenous language use may be sustained or at risk. More broadly, the results point to the evolutionary dynamics that shaped the current distribution of the world's linguistic diversity.
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Affiliation(s)
- Cecilia Padilla-Iglesias
- Department of Anthropology, University of Zurich, Zurich, Switzerland
- Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, University of Cambridge, Cambridge, United Kingdom
| | - Karen L. Kramer
- Anthropology Department, University of Utah, Salt Lake City, UT, United States
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28
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Sear R. The male breadwinner nuclear family is not the 'traditional' human family, and promotion of this myth may have adverse health consequences. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200020. [PMID: 33938277 PMCID: PMC8090810 DOI: 10.1098/rstb.2020.0020] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 11/12/2022] Open
Abstract
The importance of social support for parental and child health and wellbeing is not yet sufficiently widely recognized. The widespread myth in Western contexts that the male breadwinner-female homemaker nuclear family is the 'traditional' family structure leads to a focus on mothers alone as the individuals with responsibility for child wellbeing. Inaccurate perceptions about the family have the potential to distort academic research and public perceptions, and hamper attempts to improve parental and child health. These perceptions may have arisen partly from academic research in disciplines that focus on the Western middle classes, where this particular family form was idealized in the mid-twentieth century, when many of these disciplines were developing their foundational research. By contrast, evidence from disciplines that take a cross-cultural or historical perspective shows that in most human societies, multiple individuals beyond the mother are typically involved in raising children: in evolutionary anthropology, it is now widely accepted that we have evolved a strategy of cooperative reproduction. Expecting mothers to care for children with little support, while expecting fathers to provide for their families with little support, is, therefore, likely to lead to adverse health consequences for mothers, fathers and children. Incorporating evidence-based evolutionary, and anthropological, perspectives into research on health is vital if we are to ensure the wellbeing of individuals across a wide range of contexts. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.
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Affiliation(s)
- Rebecca Sear
- London School of Hygiene and Tropical Medicine, London, UK
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29
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Page AE, Emmott EH, Dyble M, Smith D, Chaudhary N, Viguier S, Migliano AB. Children are important too: juvenile playgroups and maternal childcare in a foraging population, the Agta. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200026. [PMID: 33938270 PMCID: PMC8090817 DOI: 10.1098/rstb.2020.0026] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2020] [Indexed: 12/19/2022] Open
Abstract
Non-maternal carers (allomothers) are hypothesized to lighten the mother's workload, allowing for the specialized human life history including relatively short interbirth intervals and multiple dependent offspring. Here, using in-depth observational data on childcare provided to 78 Agta children (a foraging population in the northern Philippines; aged 0-6 years), we explore whether allomaternal childcare substitutes and decreases maternal childcare. We found that allomother caregiving was associated with reduced maternal childcare, but the substitutive effect varied depending on the source and type of care. Children-only playgroups consistently predicted a decrease in maternal childcare. While grandmothers were rarely available, their presence was negatively associated with maternal presence and childcare, and grandmothers performed similar childcare activities to mothers. These results underscore the importance of allomothering in reducing maternal childcare in the Agta. Our findings suggest that flexibility in childcare sources, including children-only playgroups, may have been the key to human life-history evolution. Overall, our results reinforce the necessity of a broad conceptualization of social support in human childcare. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.
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Affiliation(s)
- Abigail E. Page
- Department of Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Emily H. Emmott
- Department of Anthropology, University College London, London, UK
| | - Mark Dyble
- Department of Anthropology, University College London, London, UK
| | - Dan Smith
- Bristol Medical School (PHS), University of Bristol, Bristol, UK
| | - Nikhil Chaudhary
- Department of Archaeology, University of Cambridge, Cambridge, UK
| | - Sylvain Viguier
- Department of Anthropology, University College London, London, UK
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Padilla-Iglesias C, Woodward AL, Goldin-Meadow S, Shneidman LA. Changing language input following market integration in a Yucatec Mayan community. PLoS One 2021; 16:e0252926. [PMID: 34153044 PMCID: PMC8216532 DOI: 10.1371/journal.pone.0252926] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/25/2021] [Indexed: 11/18/2022] Open
Abstract
Like many indigenous populations worldwide, Yucatec Maya communities are rapidly undergoing change as they become more connected with urban centers and access to formal education, wage labour, and market goods became more accessible to their inhabitants. However, little is known about how these changes affect children's language input. Here, we provide the first systematic assessment of the quantity, type, source, and language of the input received by 29 Yucatec Maya infants born six years apart in communities where increased contact with urban centres has resulted in a greater exposure to the dominant surrounding language, Spanish. Results show that infants from the second cohort received less directed input than infants in the first and, when directly addressed, most of their input was in Spanish. To investigate the mechanisms driving the observed patterns, we interviewed 126 adults from the communities. Against common assumptions, we showed that reductions in Mayan input did not simply result from speakers devaluing the Maya language. Instead, changes in input could be attributed to changes in childcare practices, as well as caregiver ethnotheories regarding the relative acquisition difficulty of each of the languages. Our study highlights the need for understanding the drivers of individual behaviour in the face of socio-demographic and economic changes as it is key for determining the fate of linguistic diversity.
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Affiliation(s)
- Cecilia Padilla-Iglesias
- Department of Archaeology, Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Cambridge, United Kingdom
- Institute of Anthropology, University of Zurich, Zurich, Switzerland
| | - Amanda L. Woodward
- Department of Psychology, University of Chicago, Chicago, IL, United States of America
| | - Susan Goldin-Meadow
- Department of Psychology, University of Chicago, Chicago, IL, United States of America
| | - Laura A. Shneidman
- Department of Psychology, Pacific Lutheran University, Tacoma, WA, United States of America
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Childhood Teaching and Learning among Savanna Pumé Hunter-Gatherers. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2021; 32:87-114. [DOI: 10.1007/s12110-021-09392-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/25/2021] [Indexed: 12/25/2022]
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32
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Starkweather KE, Keith MH, Prall SP, Alam N, Zohora F, Emery Thompson M. Are fathers a good substitute for mothers? Paternal care and growth rates in Shodagor children. Dev Psychobiol 2021; 63:e22148. [PMID: 34087947 DOI: 10.1002/dev.22148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 12/21/2022]
Abstract
Biparental care is a hallmark of human social organization, though paternal investment varies between and within societies. The facultative nature of paternal care in humans suggests males should invest when their care improves child survival and/or quality, though testing this prediction can be challenging because of the difficulties of empirically isolating paternal effects from those of other caregivers. Additionally, the broader context in which care is provided, vis-à-vis care from mothers and others, may lead to different child outcomes. Here, we examine the effects of paternal care on child growth among Shodagor fisher-traders, where fathers provide high levels of both additive and substitutive care, relative to mothers. We modeled seasonal z-scores and velocities for height, weight, and body mass index (BMI) outcomes using linear mixed models. Our evidence indicates that, as predicted, the context of paternal care is an important predictor of child outcomes. Results show that environmental seasonality and alloparental help contribute to a nuanced understanding of the impact of Shodagor paternal care on child physiology.
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Affiliation(s)
- K E Starkweather
- Department of Anthropology, University of Illinois Chicago, Chicago, Illinois.,Department of Anthropology, University of New Mexico, Albuquerque, New Mexico.,Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - M H Keith
- Department of Anthropology, University of Washington, Seattle, Washington
| | - S P Prall
- Department of Anthropology, University of Missouri, Columbia, Missouri
| | - N Alam
- Health Systems and Population Studies Division, ICDDR,B, Dhaka, Bangladesh
| | - F Zohora
- Health Systems and Population Studies Division, ICDDR,B, Dhaka, Bangladesh
| | - M Emery Thompson
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico
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Azcorra H, Bogin B, Dickinson F, Varela-Silva MI. Maternal Grandmothers' Household Residency, Children's Growth, and Body Composition Are Not Related in Urban Maya Families from Yucatan. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2021; 32:434-449. [PMID: 34061322 DOI: 10.1007/s12110-021-09402-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/07/2021] [Indexed: 10/21/2022]
Abstract
This study analyzes the influence of grandmothers' household residency on the presence of low height-for-age and excessive fat (FMI = fat mass [kg]/height [m2]), waist circumference, and sum of triceps and subscapular skinfolds in a sample of 247 6- to 8-year-old urban Maya children from Yucatan, Mexico. Between September 2011 and January 2014, we obtained anthropometric and body composition data from children and mothers, as well as socioeconomic characteristics of participants and households. Grandmothers' place of residence was categorized as either in the same household as their grandchildren (n = 71) or in separate households (n = 176). Multiple logistic regression models were used to analyze the association between grandmothers' residency and outcome variables. Models were adjusted for maternal anthropometric characteristics and the following socioeconomic variables: family size, location, maternal education, monthly family income, and household crowding. Models showed that the presence of grandmothers in their grandchildren's households was not associated with any of the outcome variables. In contrast, larger family size, overcrowding in the household, and lower family income predicted low height-for-age in children. Larger family size decreased the risk for being overweight based on the three parameters of body composition. Overcrowding in the household increased the risk for greater skinfolds thickness, while low family income increased the risk for higher fat mass index. The residency of grandmothers in their adult daughters' households is not significantly associated with the outcome variables in this sample of urban Maya families. Instead, maternal anthropometric characteristics and socioeconomic conditions of the family have a greater influence on the overall growth of children.
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Affiliation(s)
- Hugo Azcorra
- Centro de Investigaciones Silvio Zavala, Universidad Modelo, Carretera a Cholul 200 metros periférico norte, Yucatán, C.P. 97310, Mérida, México.
| | - Barry Bogin
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Federico Dickinson
- Departamento de Ecología Humana, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Yucatán, Mérida, México
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Page AE, Emmott EH, Myers S. Testing the buffering hypothesis: Breastfeeding problems, cessation, and social support in the UK. Am J Hum Biol 2021; 34:e23621. [PMID: 34056792 DOI: 10.1002/ajhb.23621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES Physical breastfeeding problems can lead women to terminate breastfeeding earlier than planned. In high-income countries such as the UK, breastfeeding problems have been attributed to the cultural and individual "inexperience" of breastfeeding, ultimately leading to lower breastfeeding rates. Yet, cross-cultural evidence suggests breastfeeding problems still occur in contexts where breastfeeding is common, prolonged, and seen publicly. This suggests breastfeeding problems are not unusual and do not necessarily lead to breastfeeding cessation. As humans evolved to raise children cooperatively, what matters for breastfeeding continuation may be the availability of social support during the postnatal period. Here, we test the hypothesis that social support buffers mothers from the negative impact breastfeeding problems have on duration. METHODS We run Cox models on a sample of 565 UK mothers who completed a retrospective online survey about infant feeding and social support in 2017-2018. RESULTS Breastfeeding problems were important predictors of cessation; however, the direction of the effect was dependent on the problem type and type of support from a range of supporters. Helpful support for discomfort issues (blocked ducts, too much milk) was significantly associated with reduced hazards of cessation, as predicted. However, helpful support for reported milk insufficiency was assoicated with an increased hazard of cessation. CONCLUSIONS Experiencing breastfeeding problems is the norm, but its impact may be mitigated via social support. Working from an interdisciplinary approach, our results highlight that a wide range of supporters who provide different types of support have potential to influence maternal breastfeeding experience.
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Affiliation(s)
- Abigail E Page
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Emily H Emmott
- UCL Anthropology, University College London, London, United Kingdom
| | - Sarah Myers
- UCL Anthropology, University College London, London, United Kingdom.,BirthRites Independent Max Planck Research Group, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Abstract
The family defines many aspects of our daily lives, and expresses a wide array of forms across individuals, cultures, ecologies and time. While the nuclear family is the norm today in developed economies, it is the exception in most other historic and cultural contexts. Yet, many aspects of how humans form the economic and reproductive groups that we recognize as families are distinct to our species. This review pursues three goals: to overview the evolutionary context in which the human family developed, to expand the conventional view of the nuclear family as the ‘traditional family’, and to provide an alternative to patrifocal explanations for family formation. To do so, first those traits that distinguish the human family are reviewed with an emphasis on the key contributions that behavioral ecology has made toward understanding dynamics within and between families, including life history, kin selection, reciprocity and conflict theoretical frameworks. An overview is then given of several seminal debates about how the family took shape, with an eye toward a more nuanced view of male parental care as the basis for family formation, and what cooperative breeding has to offer as an alternative perspective.
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Mother’s Partnership Status and Allomothering Networks in the United Kingdom and United States. SOCIAL SCIENCES-BASEL 2021. [DOI: 10.3390/socsci10050182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In high-income, low-fertility (HILF) settings, the mother’s partner is a key provider of childcare. However, it is not clear how mothers without partners draw on other sources of support to raise children. This paper reports the findings from a survey of 1532 women in the United Kingdom and the United States, in which women described who provided childcare for a focal child and how frequently they did so. We use multivariate Bayesian regression models to explore the drivers of support from partners, maternal kin, and other allomothers, as well as the potential impact of allomothering on women’s fertility. Relative to mothers who are in a stable first marriage or cohabitation, mothers who are unpartnered rely more heavily on fewer maternal kin, use more paid help, and have networks which include more non-kin helpers. Repartnered mothers received less help from their partners in the UK and less help from maternal kin in both countries, which US mothers compensated for by relying on other helpers. While repartnered mothers had higher age-adjusted fertility than women in a first partnership, allomaternal support was not clearly related to the mother’s fertility. These findings demonstrate the importance of partners but also of allomothering more broadly in HILF settings.
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37
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Fuentes A. Searching for the “Roots” of Masculinity in Primates and the Human Evolutionary Past. CURRENT ANTHROPOLOGY 2021. [DOI: 10.1086/711582] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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38
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Jasienska G. Costs of reproduction and ageing in the human female. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190615. [PMID: 32951546 PMCID: PMC7540952 DOI: 10.1098/rstb.2019.0615] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2020] [Indexed: 12/27/2022] Open
Abstract
Evolutionary theories of ageing point to reproduction as a significant factor to consider when asking why ageing occurs and why there is inter-individual variation in its progression. Reproduction in human females is costly, in terms of energy, nutrients and metabolic adjustments. Thus, it is expected that women who experienced high reproductive effort resulting from multiple reproductive events will age faster. However, the evidence for long-term negative effects of reproduction is not conclusive. The lack of understanding of whether there are trade-offs between reproduction and ageing in women is partly due to methodological challenges. The costs of reproduction are often calculated based only on parity, while other elements contributing to these costs (e.g. breastfeeding, timing of reproduction) are neglected, which may significantly underestimate the total costs and obscure the all-important inter-individual variation in such costs. Costs must be evaluated in relation to individual characteristics, including developmental conditions, nutritional status and social support that a mother receives during reproduction. Furthermore, ageing and health must be assessed based on comprehensive markers rather than arbitrarily assembled variables. Finally, longitudinal rather than cross-sectional studies and new statistical approaches are needed to reveal how much of a decline in health and progressing ageing can actually be attributed to past reproductive processes. This article is part of the theme issue 'Evolution of the primate ageing process'.
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Affiliation(s)
- Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
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39
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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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Martin JS, Ringen EJ, Duda P, Jaeggi AV. Harsh environments promote alloparental care across human societies. Proc Biol Sci 2020; 287:20200758. [PMID: 32811302 DOI: 10.1098/rspb.2020.0758] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Alloparental care is central to human life history, which integrates exceptionally short interbirth intervals and large birth size with an extended period of juvenile dependency and increased longevity. Formal models, previous comparative research, and palaeoanthropological evidence suggest that humans evolved higher levels of cooperative childcare in response to increasingly harsh environments. Although this hypothesis remains difficult to test directly, the relative importance of alloparental care varies across human societies, providing an opportunity to assess how local social and ecological factors influence the expression of this behaviour. We therefore, investigated associations between alloparental infant care and socioecology across 141 non-industrialized societies. We predicted increased alloparental care in harsher environments, due to the fitness benefits of cooperation in response to shared ecological challenges. We also predicted that starvation would decrease alloparental care, due to prohibitive energetic costs. Using Bayesian phylogenetic multilevel models, we tested these predictions while accounting for potential confounds as well as for population history. Consistent with our hypotheses, we found increased alloparental infant care in regions characterized by both reduced climate predictability and relatively lower average temperatures and precipitation. We also observed reduced alloparental care under conditions of high starvation. These results provide evidence of plasticity in human alloparenting in response to ecological contexts, comparable to previously observed patterns across avian and mammalian cooperative breeders. This suggests convergent social evolutionary processes may underlie both inter- and intraspecific variation in alloparental care.
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Affiliation(s)
- J S Martin
- Human Ecology Group, Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland.,Department of Anthropology, Emory University, Atlanta, GA, USA
| | - E J Ringen
- Department of Anthropology, Emory University, Atlanta, GA, USA
| | - P Duda
- Department of Zoology, University of South Bohemia, Ceske Budejovice, Jihočeský, Czechia
| | - A V Jaeggi
- Human Ecology Group, Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland.,Department of Anthropology, Emory University, Atlanta, GA, USA
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Padilla-Iglesias C, Foley RA, Shneidman LA. Language as a marker of ethnic identity among the Yucatec Maya. EVOLUTIONARY HUMAN SCIENCES 2020; 2:e38. [PMID: 37588346 PMCID: PMC10427450 DOI: 10.1017/ehs.2020.39] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Most human variation is structured around symbolically marked cultural ('ethnic') groups that require common codes of communication. Consequently, many have hypothesised that using others' linguistic competences as markers of their descent is part of an evolved human psychology. However, there is also evidence that the use of language as ethnic markers is not universally applied, but context specific. We explore the tension between these views by studying responses to bilingualism among 121 adults living in Mayan communities undergoing rapid socioeconomic changes involving increased contact with Spanish-speaking towns. We show that, although competences in Mayan were strongly tied to perceiving others as having a Mayan ethnic identity, ethnolinguistic category membership was not seen as stable through life, vertically transmitted, nor regarded as incompatible with competences in Spanish. Moreover, we find variation in how people reasoned about ethnolinguistic identities depending on their own linguistic repertoires. Our work suggests that, while there may be an evolved predisposition to use language as a signal of group identity, our developmental plasticity allows us to respond adaptively to social information around us, leading to psychological and behavioural variation within and across populations. How people reason about others based on their linguistic profiles will affect the payoffs of acquiring different languages and ultimately the long-term sustainability of linguistic diversity.
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Affiliation(s)
- Cecilia Padilla-Iglesias
- Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, University of Cambridge, Cambridge, UK
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Robert A. Foley
- Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, University of Cambridge, Cambridge, UK
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Waynforth D. Kin-based alloparenting and infant hospital admissions in the UK Millennium cohort. Evol Med Public Health 2020. [DOI: 10.1093/emph/eoaa014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background and objectives
Kin-selected altruism is an evolutionary explanation for why biological kin other than parents are willing childcare providers or alloparents. Kin alloparents may increase lineage fitness by reducing maternal energy depletion and improving child survival through childcare activities. The aim of this research was to apply the hypothesis that kin-based alloparental care has benefits for child health in a western, educated, industrialized, rich, democratic context.
Methodology
The hypothesis was tested using the first sweep of the UK Millennium Cohort Study (n = 18 552 infants). The outcome was number of hospitalizations by age 9 months, and the main predictors were kin-based alloparental care during work hours, socioeconomic position and infant health-related variables and their interactions with kin-based alloparenting. Analysis of hospitalizations was carried out using negative binomial regression.
Results
Kin alloparents were primary day carers in 17% of households. Infants whose main care arrangement during work hours was with kin allocarers had statistically significantly fewer hospitalizations than infants in all other care arrangements combined (Incidence rate ratio = 0.86, P < 0.03), and when contrasted with maternal day care (Incidence rate ratio = 0.79, P < 0.02).
Conclusions and implications
Kin-based allocare was associated with about a 15% reduction in the risk of infant hospitalization in the first 9 months. The difference appeared to be due in part to a difference in the risk of hospitalization for infectious diseases. Sensitivity analyses indicated that infants cared for by their mother during the day rather than in day-care facilities were most at risk of hospitalization compared with those in kin-based care.
Lay summary
Modern industrialized societies are generally characterized by nuclear family households, with grandparents and other extended family often living a considerable distance away. Studies carried out in societies which have not undergone the fragmentation of extended families have shown that grandmothers and other biological kin reduce infant mortality, most likely because they distribute the burden of infant care so that it does not fall exclusively on the mother. Here, the hypothesis that grandparental and other family care would be beneficial for infant health in the contemporary UK was testing using the UK Millennium cohort. Infant health was measured as number of hospitalizations in the first 9 months from birth. The main findings were that kin-based infant care, which was most commonly by grandparents, was associated with a 15% reduction in the risk of hospitalization in infants up to 9 months of age. Further analysis suggested that the difference was larger for risk of infant hospitalization due to infectious diseases rather than non-infectious diseases. The results also suggested that the finding may have been driven by increased risk for infants of mothers caring for their infant during normal working hours with no other help, such as from the father or pay-for day-care.
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Affiliation(s)
- David Waynforth
- School of Medicine, Faculty of Health Sciences, Bond University, Gold Coast, QLD 4229, Australia
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43
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Kawamoto T. Association Between Sibling Composition in the Family of Origin and Moral Foundations in Adulthood. JOURNAL OF ADULT DEVELOPMENT 2020. [DOI: 10.1007/s10804-020-09354-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Scelza BA, Hinde K. Crucial Contributions : A Biocultural Study of Grandmothering During the Perinatal Period. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2020; 30:371-397. [PMID: 31802396 PMCID: PMC6911617 DOI: 10.1007/s12110-019-09356-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Maternal grandmothers play a key role in allomaternal care, directly caring for and provisioning their grandchildren as well as helping their daughters with household chores and productive labor. Previous studies have investigated these contributions across a broad time period, from infancy through toddlerhood. Here, we extend and refine the grandmothering literature to investigate the perinatal period as a critical window for grandmaternal contributions. We propose that mother-daughter co-residence during this period affords targeted grandmaternal effort during a period of heightened vulnerability and appreciable impact. We conducted two focus groups and 37 semi-structured interviews with Himba women. Interviews focused on experiences from their first and, if applicable, their most recent birth and included information on social support, domains of teaching and learning, and infant feeding practices. Our qualitative findings reveal three domains in which grandmothers contribute: learning to mother, breastfeeding support, and postnatal health and well-being. We show that informational, emotional, and instrumental support provided to new mothers and their neonates during the perinatal period can aid in the establishment of the mother-infant bond, buffer maternal energy balance, and improve nutritional outcomes for infants. These findings demonstrate that the role of grandmother can be crucial, even when alloparenting is common and breastfeeding is frequent and highly visible. Situated within the broader anthropological and clinical literature, these findings substantiate the claim that humans have evolved in an adaptive sociocultural perinatal complex in which grandmothers provide significant contributions to the health and well-being of their reproductive-age daughters and grandchildren.
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Affiliation(s)
- Brooke A Scelza
- Department of Anthropology, UCLA, Los Angeles, CA, 90095-1553, USA. .,Center for Behavior, Evolution and Culture, UCLA, Los Angeles, CA, 90095-1553, USA.
| | - Katie Hinde
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, 85287, USA.,Center for Evolution and Medicine, Arizona State University, Tempe, AZ, 85287, USA
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Kramer KL. How There Got to Be So Many of Us: The Evolutionary Story of Population Growth and a Life History of Cooperation. JOURNAL OF ANTHROPOLOGICAL RESEARCH 2019. [DOI: 10.1086/705943] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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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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Singletary B. What are the benefits of having a village? Effects of allomaternal care on communicative skills in early infancy. Infant Behav Dev 2019; 57:101361. [PMID: 31491616 DOI: 10.1016/j.infbeh.2019.101361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/31/2019] [Accepted: 08/20/2019] [Indexed: 11/19/2022]
Abstract
This study investigates whether exposure to allomaternal care (AMC-care for infants from individuals other than the mother) improves rates of communicative behaviors during late infancy by providing more opportunities to practice communicating with varied caregivers. Data were collected from 102 typically-developing infants aged 13-18 months and their mothers. AMC variables were collected using a current care questionnaire, structured 14-day diary, and longitudinal interview. Communicative behaviors were assessed through post hoc microcoding of in-lab administrations of the Early Social Communication Scales (ESCS), as well as additional microcoding of the Bayley III Screening Cognitive Subtest. Demographic covariates were also included. For each communicative behavior, backward model selection was used to determine the best fitting linear regression model. Results suggested that rates of turn-taking decreased with Household AMC (p < 0.008), but increased with two or more siblings present at home (p < 0.01). Conversely, rates of spontaneous giving increased with Household AMC (p < 0.003) regardless of the presence of siblings. Notably, exposure to more AMC was neither helpful nor harmful for many of the tested communicative behaviors, although the number of siblings present was significantly related to rates of following commands, as well as pointing and reaching. Ultimately, this study suggests that household level experiences with AMC, rather than formalized care, impact the development of some communicative behaviors during late infancy.
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Affiliation(s)
- Britt Singletary
- School of Anthropology, University of Arizona, 1009 East South Campus Dr., P.O. Box 210030, Tucson, AZ 85721-0030, United States.
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Schacht R, Kramer KL. Are We Monogamous? A Review of the Evolution of Pair-Bonding in Humans and Its Contemporary Variation Cross-Culturally. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00230] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Rosenbaum S, Gettler LT. With a little help from her friends (and family) part II: Non-maternal caregiving behavior and physiology in mammals. Physiol Behav 2019; 193:12-24. [PMID: 29933837 DOI: 10.1016/j.physbeh.2017.12.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/21/2017] [Indexed: 12/15/2022]
Abstract
The diversity of competing frameworks for explaining the evolution of non-maternal care in mammals (Part I, this issue) reflects the vast range of behaviors and associated outcomes these theories attempt to subsume. Caretaking comprises a wide variety of behavioral domains, and is mediated by an equally large range of physiological systems. In Part II, we provide an overview of how non-maternal care in mammals is expressed, the ways in which it is regulated, and the many effects such care has on both recipients and caretakers. We also discuss the two primary ways in which closer integration of ultimate and proximate levels of explanation can be useful when addressing questions about non-maternal caretaking. Specifically, proximate mechanisms provide important functional clues, and are key to testing theory concerning evolutionary tradeoffs. Finally, we highlight a number of methodological and publication biases that currently shape the literature, which provide opportunities for knowledge advancement in this domain going forward. In this conclusion to our two-part introduction, we provide a broad survey of the behavior and physiology that the contributions to this special issue represent.
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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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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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