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De Dreu CKW, Gross J, Romano A. Group Formation and the Evolution of Human Social Organization. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2024; 19:320-334. [PMID: 37450408 PMCID: PMC10913362 DOI: 10.1177/17456916231179156] [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] [Indexed: 07/18/2023]
Abstract
Humans operate in groups that are oftentimes nested in multilayered collectives such as work units within departments and companies, neighborhoods within cities, and regions within nation states. With psychological science mostly focusing on proximate reasons for individuals to join existing groups and how existing groups function, we still poorly understand why groups form ex nihilo, how groups evolve into complex multilayered social structures, and what explains fission-fusion dynamics. Here we address group formation and the evolution of social organization at both the proximate and ultimate level of analysis. Building on models of fitness interdependence and cooperation, we propose that socioecologies can create positive interdependencies among strangers and pave the way for the formation of stable coalitions and groups through reciprocity and reputation-based partner selection. Such groups are marked by in-group bounded, parochial cooperation together with an array of social institutions for managing the commons, allowing groups to scale in size and complexity while avoiding the breakdown of cooperation. Our analysis reveals how distinct group cultures can endogenously emerge from reciprocal cooperation, shows that social identification and group commitment are likely consequences rather than causes of group cooperation, and explains when intergroup relations gravitate toward peaceful coexistence, integration, or conflict.
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Affiliation(s)
| | - Jörg Gross
- Department of Psychology, University of Zurich
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2
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Phelps JR, Pitogo KME, Emit AT, Hill K. Inter-household transfers of material goods among Sama "sea nomads" of the Philippines: Reciprocity, helping, signaling, or something else? PLoS One 2023; 18:e0290270. [PMID: 37616297 PMCID: PMC10449209 DOI: 10.1371/journal.pone.0290270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 08/02/2023] [Indexed: 08/26/2023] Open
Abstract
The extent to which humans share with both kin and non-kin is a defining characteristic of our species. Evolutionary research suggests that pervasive reliance on inter-individual transfers of goods and services may have evolved to support a cooperative breeding adaptation in humans. However, while intensive food sharing between individuals and families has frequently been investigated in small-scale human societies, a comprehensive analysis of the daily transfers of all material goods has not been attempted. Likewise, while much previous research on cooperative transfers focused on terrestrial foraging populations, less attention is paid to other small-scale economic modalities traditionally inhabited by humans. Drawing on over three years' worth of interviews and observational data from a community of primarily ethnic Sama people residing along the coast of Southern Mindanao Island in the Philippines, this paper examines the overall transfer patterns of material goods in a marine foraging economy. A quantitative description of resource acquisition is followed by an in-depth exploration of the characteristics of individual households and household dyads who gave and/or received more during the study period. Results indicate that a household's age and income are consistently correlated with increased inflow and outflow of material goods. Results also suggest differential motivations underlie inter-household sharing of food, money, and other goods in the study community. Most importantly, we find that both daily and long-term reciprocity overwhelmingly drive sharing within household dyads in the study community, despite secondary effects of kinship, relative need, and relative household age between household dyads.
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Affiliation(s)
- Julia R. Phelps
- School of Human Evolution and Social Change, Institute of Human Origins, Arizona State University, Tempe, Arizona, United States of America
| | - Kier Mitchel E. Pitogo
- Institute of Biological Sciences, University of the Philippines Los Baños, Los Baños, Laguna, Philippines
| | - Angelica T. Emit
- Department of Marine Biology, Mindanao State University, General Santos, South Cotabato, Philippines
| | - Kim Hill
- School of Human Evolution and Social Change, Institute of Human Origins, Arizona State University, Tempe, Arizona, United States of America
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3
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Delton AW, Jaeggi AV, Lim J, Sznycer D, Gurven M, Robertson TE, Sugiyama LS, Cosmides L, Tooby J. Cognitive foundations for helping and harming others: Making welfare tradeoffs in industrialized and small-scale societies. EVOL HUM BEHAV 2023. [DOI: 10.1016/j.evolhumbehav.2023.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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4
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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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5
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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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6
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Martin JS, Jaeggi AV, Koski SE. The social evolution of individual differences: Future directions for a comparative science of personality in social behavior. Neurosci Biobehav Rev 2023; 144:104980. [PMID: 36463970 DOI: 10.1016/j.neubiorev.2022.104980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/21/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022]
Abstract
Personality is essential for understanding the evolution of cooperation and conflict in behavior. However, personality science remains disconnected from the field of social evolution, limiting our ability to explain how personality and plasticity shape phenotypic adaptation in social behavior. Researchers also lack an integrative framework for comparing personality in the contextualized and multifaceted behaviors central to social interactions among humans and other animals. Here we address these challenges by developing a social evolutionary approach to personality, synthesizing theory, methods, and organizing questions in the study of individuality and sociality in behavior. We critically review current measurement practices and introduce social reaction norm models for comparative research on the evolution of personality in social environments. These models demonstrate that social plasticity affects the heritable variance of personality, and that individual differences in social plasticity can further modify the rate and direction of adaptive social evolution. Future empirical studies of frequency- and density-dependent social selection on personality are crucial for further developing this framework and testing adaptive theory of social niche specialization.
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Affiliation(s)
- Jordan S Martin
- Human Ecology Group, Institute of Evolutionary Medicine, University of Zurich, Switzerland.
| | - Adrian V Jaeggi
- Human Ecology Group, Institute of Evolutionary Medicine, University of Zurich, Switzerland.
| | - Sonja E Koski
- Organismal and Evolutionary Biology, University of Helsinki, Finland.
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Eisenbruch AB, Krasnow MM. Why Warmth Matters More Than Competence: A New Evolutionary Approach. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2022; 17:1604-1623. [PMID: 35748187 DOI: 10.1177/17456916211071087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Multiple lines of evidence suggest that there are two major dimensions of social perception, often called warmth and competence, and that warmth is prioritized over competence in multiple types of social decision-making. Existing explanations for this prioritization argue that warmth is more consequential for an observer's welfare than is competence. We present a new explanation for the prioritization of warmth based on humans' evolutionary history of cooperative partner choice. We argue that the prioritization of warmth evolved because ancestral humans faced greater variance in the warmth of potential cooperative partners than in their competence but greater variance in competence over time within cooperative relationships. These each made warmth more predictive than competence of the future benefits of a relationship, but because of differences in the distributions of these traits, not because of differences in their intrinsic consequentiality. A broad, synthetic review of the anthropological literature suggests that these conditions were characteristic of the ecologies in which human social cognition evolved, and agent-based models demonstrate the plausibility of these selection pressures. We conclude with future directions for the study of preferences and the further integration of social and evolutionary psychology.
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Affiliation(s)
| | - Max M Krasnow
- Division of Continuing Education, Harvard University
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8
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Hunt AD, Jaeggi AV. Specialised minds: extending adaptive explanations of personality to the evolution of psychopathology. EVOLUTIONARY HUMAN SCIENCES 2022; 4:e26. [PMID: 37588937 PMCID: PMC10426115 DOI: 10.1017/ehs.2022.23] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Traditional evolutionary theory invoked natural and sexual selection to explain species- and sex-typical traits. However, some heritable inter-individual variability in behaviour and psychology - personality - is probably adaptive. Here we extend this insight to common psychopathological traits. Reviewing key findings from three background areas of importance - theoretical models, non-human personality and evolved human social dynamics - we propose that a combination of social niche specialisation, negative frequency-dependency, balancing selection and adaptive developmental plasticity should explain adaptation for individual differences in psychology - 'specialised minds' - explaining some variance in personality and psychopathology trait dimensions, which share various characteristics. We suggest that anthropological research of behavioural differences should be extended past broad demographic factors (age and sex) to include individual specialisations. As a first step towards grounding psychopathology in ancestral social structure, we propose a minimum plausible prevalence, given likely ancestral group sizes, for negatively frequency-dependent phenotypes to be maintained as specialised tails of adaptive distributions - below the calculated prevalence, specialisation is highly unlikely. For instance, chronic highly debilitating forms of autism or schizophrenia are too rare for such explanations, whereas attention-deficit-hyperactivity disorder and broad autism phenotypes are common enough to have existed in most hunter-gatherer bands, making adaptive explanations more plausible.
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Affiliation(s)
- Adam D. Hunt
- Institute of Evolutionary Medicine, University of Zürich, Switzerland
| | - Adrian V. Jaeggi
- Institute of Evolutionary Medicine, University of Zürich, Switzerland
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9
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How small-scale societies achieve large-scale cooperation. Curr Opin Psychol 2021; 44:44-48. [PMID: 34562700 DOI: 10.1016/j.copsyc.2021.08.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 11/22/2022]
Abstract
For most of our species' history, humans have lived in relatively small subsistence communities, often called small-scale societies. While these groups lack centralized institutions, they can and often do maintain large-scale cooperation. Here, we explore several mechanisms promoting cooperation in small-scale societies, including (a) the development of social norms that encourage prosocial behavior, (b) reciprocal exchange relationships, (c) reputation that facilitates high-cost cooperation, (d) relational wealth, and (e) risk buffering institutions. We illustrate these with ethnographic and psychological evidence from contemporary small-scale societies. We argue that these mechanisms for cooperation helped past and present small-scale communities adapt to diverse ecological and social niches.
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10
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Abstract
The importance of kin relationships varies with socioecological demands. Among subsistence agriculturalists, people commonly manage fluctuations in food availability by relying on family members to share resources and pool labor. However, the process of market integration may disrupt these support networks, which may begin to carry costs or liabilities in novel market environments. The current study aims to address (1) how kin are distributed in household support networks (2) how kin support varies as households become more engaged in market activities, and (3) how variation in kin support is associated with income disparities within a Yucatec Maya community undergoing rapid market integration. Using long-term census data combined with social networks and detailed household economic data, we find that household support networks are primarily composed of related households. Second, households engaged predominantly in wage labor rely less on kin support than agricultural or mixed economy households. Finally, kin support is associated with lower household net income and income per capita. Understanding how kin support systems shift over the course of market integration and in the face of new opportunities for social and economic production provides a unique window into the social and economic drivers of human family formation.
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11
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Powers ST, van Schaik CP, Lehmann L. Cooperation in large-scale human societies-What, if anything, makes it unique, and how did it evolve? Evol Anthropol 2021; 30:280-293. [PMID: 34085349 DOI: 10.1002/evan.21909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 10/07/2020] [Accepted: 04/27/2021] [Indexed: 11/07/2022]
Abstract
To resolve the major controversy about why prosocial behaviors persist in large-scale human societies, we propose that two questions need to be answered. First, how do social interactions in small-scale and large-scale societies differ? By reviewing the exchange and collective-action dilemmas in both small-scale and large-scale societies, we show they are not different. Second, are individual decision-making mechanisms driven by self-interest? We extract from the literature three types of individual decision-making mechanism, which differ in their social influence and sensitivity to self-interest, to conclude that humans interacting with non-relatives are largely driven by self-interest. We then ask: what was the key mechanism that allowed prosocial behaviors to continue as societies grew? We show the key role played by new social interaction mechanisms-change in the rules of exchange and collective-action dilemmas-devised by the interacting individuals, which allow for self-interested individuals to remain prosocial as societies grow.
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Affiliation(s)
- Simon T Powers
- School of Computing, Edinburgh Napier University, Edinburgh, UK
| | | | - Laurent Lehmann
- Department of Ecology & Evolution, University of Lausanne, Lausanne, Switzerland
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12
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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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13
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Jaeggi AV, Blackwell AD, von Rueden C, Trumble BC, Stieglitz J, Garcia AR, Kraft TS, Beheim BA, Hooper PL, Kaplan H, Gurven M. Do wealth and inequality associate with health in a small-scale subsistence society? eLife 2021; 10:59437. [PMID: 33988506 PMCID: PMC8225390 DOI: 10.7554/elife.59437] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 05/10/2021] [Indexed: 12/11/2022] Open
Abstract
In high-income countries, one’s relative socio-economic position and economic inequality may affect health and well-being, arguably via psychosocial stress. We tested this in a small-scale subsistence society, the Tsimane, by associating relative household wealth (n = 871) and community-level wealth inequality (n = 40, Gini = 0.15–0.53) with a range of psychological variables, stressors, and health outcomes (depressive symptoms [n = 670], social conflicts [n = 401], non-social problems [n = 398], social support [n = 399], cortisol [n = 811], body mass index [n = 9,926], blood pressure [n = 3,195], self-rated health [n = 2523], morbidities [n = 1542]) controlling for community-average wealth, age, sex, household size, community size, and distance to markets. Wealthier people largely had better outcomes while inequality associated with more respiratory disease, a leading cause of mortality. Greater inequality and lower wealth were associated with higher blood pressure. Psychosocial factors did not mediate wealth-health associations. Thus, relative socio-economic position and inequality may affect health across diverse societies, though this is likely exacerbated in high-income countries. Poverty is bad for health. People living in poverty are more likely to struggle to afford nutritious food, lack access to health care, or be overworked or stressed. This may make them susceptible to chronic diseases, contribute to faster aging, and shorten their lifespans. In high-income countries, there is growing evidence to suggest that a person’s ‘rank’ in society also impacts their health. For example, individuals who have a lower position in the social hierarchy report worse health outcomes, regardless of their incomes. But it is unclear why living in an unequal society or having a lower social status contributes to poorer health. One possibility is that inequalities in society are creating a stressful environment that leads to worse physical and mental outcomes. It is thought that this stress largely comes from how humans evolved to prioritize reaching a higher social status over having a long and healthy life. If this is the case, this would mean that the link between social status and health would also be present in non-industrialized communities where social hierarchies tend to be less pronounced. To test this, Jaeggi, Blackwell et al. studied the Indigenous Tsimane population in Bolivia who live in small communities and forage and farm their own food. The income and relative wealth of 870 households from 40 Tsimane communities were compared against various outcomes, including symptoms associated with depression, stress hormone levels, blood pressure, self-rated health and several diseases. Jaeggi, Blackwell et al. found poverty and inequality did not negatively impact all of the health outcomes measured as has been previously reported for industrialized societies. However, blood pressure was higher among people with lower incomes or those who lived in more unequal communities. But because the Tsimane people generally have low blood pressure, the differences were too small to have much effect on their health. People who lived in more unequal communities were also three times more likely to have respiratory infections, but the reason for this was unclear. This shows that social determinants such as a person’s wealth or inequality can affect health, even in communities with less rigid social hierarchies. In industrial societies the effect may be worse in part because they are compounded by lifestyle factors, such as diets rich in fat and sugar, and physical inactivity which can also increase blood pressure. This information may help policy makers reduce health disparities by addressing some of the social determinants of health and the lifestyle factors that cause them.
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Affiliation(s)
- Adrian V Jaeggi
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland.,Department of Anthropology, Emory University, Atlanta, United States
| | - Aaron D Blackwell
- Department of Anthropology, Washington State University, Pulman, United States
| | | | - Benjamin C Trumble
- School of Human Evolution and Social Change, Arizona State University, Tempe, United States.,Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, United States
| | | | - Angela R Garcia
- Department of Anthropology, Emory University, Atlanta, United States.,School of Human Evolution and Social Change, Arizona State University, Tempe, United States.,Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, United States
| | - Thomas S Kraft
- Department of Anthropology, University of California, Santa Barbara, Santa Barbara, United States
| | - Bret A Beheim
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Paul L Hooper
- Economic Science Institute, Chapman University, Irvine, United States.,Department of Anthropology, University of New Mexico, Albuquerque, United States
| | - Hillard Kaplan
- Economic Science Institute, Chapman University, Irvine, United States
| | - Michael Gurven
- Department of Anthropology, University of California, Santa Barbara, Santa Barbara, United States
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West SA, Cooper GA, Ghoul MB, Griffin AS. Ten recent insights for our understanding of cooperation. Nat Ecol Evol 2021; 5:419-430. [PMID: 33510431 PMCID: PMC7612052 DOI: 10.1038/s41559-020-01384-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 12/11/2020] [Indexed: 01/29/2023]
Abstract
Since Hamilton published his seminal papers in 1964, our understanding of the importance of cooperation for life on Earth has evolved beyond recognition. Early research was focused on altruism in the social insects, where the problem of cooperation was easy to see. In more recent years, research into cooperation has expanded across the entire tree of life, and has been revolutionized by advances in genetic, microbiological and analytical techniques. We highlight ten insights that have arisen from these advances, which have illuminated generalizations across different taxa, making the world simpler to explain. Furthermore, progress in these areas has opened up numerous new problems to solve, suggesting exciting directions for future research.
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Affiliation(s)
- Stuart A West
- Department of Zoology, University of Oxford, Oxford, UK.
| | - Guy A Cooper
- Department of Zoology, University of Oxford, Oxford, UK
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15
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Pisor AC, Jones JH. Do people manage climate risk through long-distance relationships? Am J Hum Biol 2020; 33:e23525. [PMID: 33103823 DOI: 10.1002/ajhb.23525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Long-distance social relationships have been a feature of human evolutionary history; evidence from the paleoanthropological, archeological, and ethnographic records suggest that one function of these relationships is to manage the risk of resource shortfalls due to climate variability. We should expect long-distance relationships to be especially important when shortfalls are chronic or temporally positively autocorrelated, as these are more likely to exhaust local adaptations for managing risk. Further, individuals who experience shortfalls not as rare shocks, but as patterned events, should be more likely to pay the costs of maintaining long-distance relationships. We test these hypotheses in the context of two communities of Bolivian horticulturalists, where climate variability-especially precipitation variability-is relevant to production and access to long-distance connections is improving. METHODS Data on individuals' migration histories, social relationships, and other relevant variables were collected in 2017 (n = 119). Precipitation data were obtained from the US National Center for Atmospheric Research, allowing us to estimate participants' exposure to drought and excess precipitation. RESULTS Exposure duration, proximity in time, and frequency did not predict having a greater number of long-distance relationships. Males, extraverted individuals, and those who had traveled more did have more long-distance relationships, however. CONCLUSION Another function of long-distance relationships is to access resources that can never be obtained locally; ethnographic data suggest this is their primary function in rural Bolivia. We conclude by refining our predictions about the conditions under which long-distance relationships are likely to help individuals manage the risks posed by climate variability.
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Affiliation(s)
- Anne C Pisor
- Department of Anthropology, Washington State University, Pullman, Washington, USA.,Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - James Holland Jones
- Department of Earth System Science, Stanford University, Stanford, California, USA
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16
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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: 13] [Impact Index Per Article: 3.3] [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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17
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Sarma MS, Boyette AH, Lew-Levy S, Miegakanda V, Kilius E, Samson DR, Gettler LT. Sex differences in daily activity intensity and energy expenditure and their relationship to cortisol among BaYaka foragers from the Congo Basin. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 172:423-437. [PMID: 32441329 DOI: 10.1002/ajpa.24075] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVES The pooling of energetic resources and food sharing have been widely documented among hunter-gatherer societies. Much less is known about how the energetic costs of daily activities are distributed across individuals in such groups, including between women and men. Moreover, the metabolic physiological correlates of those activities and costs are relatively understudied. MATERIALS AND METHODS Here, we tracked physical activity, energy expenditure (EE), and cortisol production among Congo Basin BaYaka foragers engaged in a variety of daily subsistence activities (n = 37). Given its role in energy mobilization, we measured overall daily cortisol production and short-term cortisol reactivity through saliva sampling; we measured physical activity levels and total EE via the wGT3X-bt actigraph and heart rate monitor. RESULTS We found that there were no sex differences in likelihood of working in common activity locations (forest, garden, house). Across the day, women spent greater percentage time in moderate-to-vigorous physical activity (%MVPA) and had lower total EE than men. Females with higher EE (kCal/hr) produced greater cortisol throughout the day. Though not statistically significant, we also found that individuals with greater %MVPA had larger decreases in cortisol reactivity. DISCUSSION BaYaka women sustained higher levels of physical activity but incurred lower energetic costs than men, even after factoring in sex differences in body composition. Our findings suggest that the distribution of physical activity demands and costs are relevant to discussions regarding how labor is divided and community energy budgets take shape in such settings.
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Affiliation(s)
- Mallika S Sarma
- Department of Anthropology, University of Notre Dame, Notre Dame, Indiana, USA
| | - Adam H Boyette
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Sheina Lew-Levy
- Department of Psychology, Simon Fraser University, Burnaby, Canada.,Department of Archeology and Heritage Studies, Aarhus University, Aarhus, Denmark
| | - Valchy Miegakanda
- Institut National de Santé Publique, Brazzaville, Republic of the Congo
| | - Erica Kilius
- Department of Anthropology, University of Toronto Mississauga, Mississauga, Canada
| | - David R Samson
- Department of Anthropology, University of Toronto Mississauga, Mississauga, Canada
| | - Lee T Gettler
- Department of Anthropology, University of Notre Dame, Notre Dame, Indiana, USA.,The Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
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18
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Lobmaier JS, Probst F, Fischbacher U, Wirthmüller U, Knoch D. Pleasant body odours, but not genetic similarity, influence trustworthiness in a modified trust game. Sci Rep 2020; 10:3388. [PMID: 32099082 PMCID: PMC7042344 DOI: 10.1038/s41598-020-60407-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 02/06/2020] [Indexed: 11/23/2022] Open
Abstract
Identifying trustworthy partners is an important adaptive challenge for establishing mutually cooperative relationships. Previous studies have demonstrated a marked relationship between a person's attractiveness and his apparent trustworthiness (beauty premium). Kin selection theory, however, suggests that cues to kinship enhance trustworthiness. Here we directly tested predictions of the beauty premium and kin selection theory by using body odours as cues to trustworthiness. Body odours reportedly portray information about an individuals' genotype at the human leucocyte antigen system (HLA) and thus olfactory cues in body odours serve as a promising means for kin recognition. Ninety men played trust games in which they divided uneven sums of monetary units between two male trustees represented by their body odour and rated each body odour for pleasantness. Half of the odours came from HLA-similar men (suggesting closer kin) and half from HLA dissimilar men (suggesting non-kin). We found that the amount of money the players transferred was not related to HLA-similarity, but to the pleasantness of the trustee's body odour. By showing that people with more pleasant body odours are trusted more than people with unpleasant body odour we provide evidence for a "beauty-premium" that overrides any putative effect of kin.
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Affiliation(s)
- Janek S Lobmaier
- Department of Social Neuroscience and Social Psychology, Institute of Psychology, University of Bern, Bern, Switzerland.
| | - Fabian Probst
- Department of Social Neuroscience and Social Psychology, Institute of Psychology, University of Bern, Bern, Switzerland
- Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland
| | - Urs Fischbacher
- Department of Economics, University of Konstanz, Konstanz, Germany
- Thurgau Institute of Economics, Kreuzlingen, Switzerland
| | - Urs Wirthmüller
- Universitätsinstitut für Klinische Chemie, University of Bern, Bern, Switzerland
| | - Daria Knoch
- Department of Social Neuroscience and Social Psychology, Institute of Psychology, University of Bern, Bern, Switzerland.
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19
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Massen JJ, Behrens F, Martin JS, Stocker M, Brosnan SF. A comparative approach to affect and cooperation. Neurosci Biobehav Rev 2019; 107:370-387. [DOI: 10.1016/j.neubiorev.2019.09.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/16/2019] [Accepted: 09/19/2019] [Indexed: 12/31/2022]
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20
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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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21
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Schultz AF. Status determinants, social incongruity and economic transition: Gender, relative material wealth and heterogeneity in the cultural lifestyle of forager-horticulturalists. PLoS One 2019; 14:e0220432. [PMID: 31480072 PMCID: PMC6721728 DOI: 10.1371/journal.pone.0220432] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/16/2019] [Indexed: 11/30/2022] Open
Abstract
For small-scale societies, transitions from self-sufficiency to cash-based labor in market economies have been associated with the exacerbation of existing, and the emergence of new, social incongruities. Social incongruity occurs when two or more of a person’s status determinants (e.g. age, gender, wealth) conflict, resulting in reduced social status. A central focus of theory and research on social incongruity is the relationship between the cultural prototype of what is needed to live a good life–or lifestyle–and status determinants. Assessment of status determinants is challenging because of their relative nature at multiple levels of analysis. This study uses theory and methods from cognitive anthropology to investigate whether and how individual knowledge of a cultural lifestyle prototype conflicts with status determinants at two levels of economic transition among 101 adults from a small-scale society of forager-horticulturalists in Bolivian Amazonia, the Tsimane’. Results support cultural consensus in a 38-item model labeled market lifestyle (explaining 72.7% of sample variance). While the model includes both overlapping traditional (e.g. weaving) and market-related (e.g. education) items and behaviors, most market alternatives were rated higher. When market lifestyle was tested for social incongruity against other status determinants, only gender predicted variation. Thematically, when lifestyle was stratified by gender, men rated several items of relational wealth higher than women did. Analysis of model residual agreement revealed heterogeneity in the form of a syncretic lifestyle model (explaining 18.2% of additional variance). Participants whose knowledge better matched syncretic lifestyle rated traditional items and market alternatives closer to parity. Agreement with the syncretic model correlated with lower material wealth and less market integration. In sum, the findings document a modern, market-oriented form of Tsimane’ lifestyle that varies ontologically from past modelling and ethnographic accounts in preferred forms of livelihood and wealth.
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Affiliation(s)
- Alan Frank Schultz
- Department of Anthropology, Baylor University, Waco, Texas, United States of America
- * E-mail:
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22
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Ringen EJ, Duda P, Jaeggi AV. The evolution of daily food sharing: A Bayesian phylogenetic analysis. EVOL HUM BEHAV 2019. [DOI: 10.1016/j.evolhumbehav.2019.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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24
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Carter GG, Schino G, Farine D. Challenges in assessing the roles of nepotism and reciprocity in cooperation networks. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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25
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Smith D, Dyble M, Major K, Page AE, Chaudhary N, Salali GD, Thompson J, Vinicius L, Migliano AB, Mace R. A friend in need is a friend indeed: Need-based sharing, rather than cooperative assortment, predicts experimental resource transfers among Agta hunter-gatherers. EVOL HUM BEHAV 2019. [DOI: 10.1016/j.evolhumbehav.2018.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Gfrerer N, Taborsky M. Working dogs transfer different tasks in reciprocal cooperation. Biol Lett 2018; 14:rsbl.2017.0460. [PMID: 29445042 DOI: 10.1098/rsbl.2017.0460] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 01/18/2018] [Indexed: 11/12/2022] Open
Abstract
Direct reciprocity can establish stable cooperation among unrelated individuals. It is a common assumption of direct reciprocity models that agents exchange like with like, but this is not necessarily true for natural interactions. It is yet unclear whether animals apply direct reciprocity rules when successive altruistic help involves different tasks. Here, we tested whether working dogs transfer help from one to another cooperative task in an iterated prisoner's dilemma paradigm. In our experiment, individual dogs received help to obtain food from a conspecific, which involved a specific task. Subsequently, the focal subject could return received favour by using a different task. Working dogs transferred the cooperative experience received through one task by applying an alternative task when they helped a previously cooperative partner. By contrast, they refrained from helping previously defecting partners. This suggests that dogs realize the cooperative act of a conspecific, which changes their propensity to provide help to that partner by different means. The ability of animals to transfer different tasks when helping a social partner by satisfying the criteria of direct reciprocity might explain the frequent occurrence of reciprocal cooperation in nature.
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Affiliation(s)
- Nastassja Gfrerer
- Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Bern, Switzerland
| | - Michael Taborsky
- Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Bern, Switzerland
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27
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Samuni L, Preis A, Mielke A, Deschner T, Wittig RM, Crockford C. Social bonds facilitate cooperative resource sharing in wild chimpanzees. Proc Biol Sci 2018; 285:rspb.2018.1643. [PMID: 30305438 DOI: 10.1098/rspb.2018.1643] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/20/2018] [Indexed: 11/12/2022] Open
Abstract
Why share when access to benefits is uncertain is crucial to our understanding of the evolution of humans' extensive cooperation. Here, we investigated some of the different human sharing hypotheses and potential neuroendocrine mechanisms, in one of our closest living relatives, chimpanzees. The strongest predictor of sharing across food types was the presence of enduring and mutually preferred grooming partners, more than harassment, direct signalling, or trade. Moreover, urinary oxytocin levels were higher after the sharing of both individually and jointly acquired resources compared with controls. We conclude that the emotional connection inherent in social bonds was a key factor determining sharing patterns, with the oxytocinergic system potentially facilitating long-term cooperative exchanges. Testing for the role of social bonds in increasing predictability of sharing behaviour, a feature frequently overlooked, may help us to identify the evolutionary drivers of resource sharing and mechanisms that sustain delayed reciprocity between non-kin.
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Affiliation(s)
- L Samuni
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany .,Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, BP 1303 Abidjan 01, Côte d'Ivoire
| | - A Preis
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.,Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, BP 1303 Abidjan 01, Côte d'Ivoire
| | - A Mielke
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.,Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, BP 1303 Abidjan 01, Côte d'Ivoire
| | - T Deschner
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - R M Wittig
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.,Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, BP 1303 Abidjan 01, Côte d'Ivoire
| | - C Crockford
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.,Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, BP 1303 Abidjan 01, Côte d'Ivoire
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28
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Ember CR, Skoggard I, Ringen EJ, Farrer M. Our better nature: Does resource stress predict beyond-household sharing? EVOL HUM BEHAV 2018. [DOI: 10.1016/j.evolhumbehav.2018.03.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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29
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Koster J. Family ties: the multilevel effects of households and kinship on the networks of individuals. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172159. [PMID: 29765670 PMCID: PMC5936935 DOI: 10.1098/rsos.172159] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
Among social mammals, humans uniquely organize themselves into communities of households that are centred around enduring, predominantly monogamous unions of men and women. As a consequence of this social organization, individuals maintain social relationships both within and across households, and potentially there is conflict among household members about which social ties to prioritize or de-emphasize. Extending the logic of structural balance theory, I predict that there will be considerable overlap in the social networks of individual household members, resulting in a pattern of group-level reciprocity. To test this prediction, I advance the Group-Structured Social Relations Model, a generalized linear mixed model that tests for group-level effects in the inter-household social networks of individuals. The empirical data stem from social support interviews conducted in a community of indigenous Nicaraguan horticulturalists, and model results show high group-level reciprocity among households. Although support networks are organized around kinship, covariates that test predictions of kin selection models do not receive strong support, potentially because most kin-directed altruism occurs within households, not between households. In addition, the models show that households with high genetic relatedness in part from children born to adulterous relationships are less likely to assist each other.
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30
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Abstract
Biological market forces shape patterns of cooperation typical of small-scale human societies that are organized by division of labor based on age and gender. Labor specialization promotes trade, while supply and demand affect the amount individuals exchange for commodities.
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Affiliation(s)
- Shane J Macfarlan
- Department of Anthropology, University of Utah, 270 S. 1400 E., Salt Lake City, UT 84112, USA.
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31
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Ready E, Power EA. Why Wage Earners Hunt: Food Sharing, Social Structure, and Influence in an Arctic Mixed Economy. CURRENT ANTHROPOLOGY 2018. [DOI: 10.1086/696018] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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32
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Thomas MG, Ji T, Wu J, He Q, Tao Y, Mace R. Kinship underlies costly cooperation in Mosuo villages. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171535. [PMID: 29515868 PMCID: PMC5830757 DOI: 10.1098/rsos.171535] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/18/2018] [Indexed: 06/10/2023]
Abstract
The relative importance of social evolution theories such as kin selection, direct reciprocity and need-based transfers in explaining real-world cooperation is the source of much debate. Previous field studies of cooperation in human communities have revealed variability in the extent to which each of these theories explains human sociality in different contexts. We conducted multivariate social network analyses predicting costly cooperation-labouring on another household's farm-in 128 082 dyads of Mosuo farming households in southwest China. Through information-theoretic model selection, we tested the roles played by genealogical relatedness, affinal relationships (including reproductive partners), reciprocity, relative need, wealth, household size, spatial proximity and gift-giving in an economic game. The best-fitting model included all factors, along with interactions between relatedness and (i) reciprocity, (ii) need, (iii) the presence of own children in another household and (iv) proximity. Our results show how a real-world form of cooperation was driven by kinship. Households tended to help kin in need (but not needy non-kin) and travel further to help spatially distant relatives. Households were more likely to establish reciprocal relationships with distant relatives and non-kin but closer kin cooperated regardless of reciprocity. These patterns of kin-driven cooperation show the importance of inclusive fitness in understanding human social behaviour.
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Affiliation(s)
- Matthew Gwynfryn Thomas
- Department of Anthropology, University College London, 14 Taviton Street, London WC1H 0BW, UK
| | - Ting Ji
- Key Laboratory of Animal Ecology and Conservation Biology, Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Jiajia Wu
- Life Sciences, Lanzhou University, 222 Tianshui South Road, Lanzhou, Gansu Province, 730000, People's Republic of China
| | - QiaoQiao He
- Key Laboratory of Animal Ecology and Conservation Biology, Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Yi Tao
- Key Laboratory of Animal Ecology and Conservation Biology, Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Ruth Mace
- Department of Anthropology, University College London, 14 Taviton Street, London WC1H 0BW, UK
- Life Sciences, Lanzhou University, 222 Tianshui South Road, Lanzhou, Gansu Province, 730000, People's Republic of China
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Wutich A, Budds J, Eichelberger L, Geere J, Harris L, Horney J, Jepson W, Norman E, O'Reilly K, Pearson A, Shah S, Shinn J, Simpson K, Staddon C, Stoler J, Teodoro MP, Young S. Advancing methods for research on household water insecurity: Studying entitlements and capabilities, socio-cultural dynamics, and political processes, institutions and governance. ACTA ACUST UNITED AC 2017. [PMID: 29532811 DOI: 10.1016/j.wasec.2017.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Household water insecurity has serious implications for the health, livelihoods and wellbeing of people around the world. Existing methods to assess the state of household water insecurity focus largely on water quality, quantity or adequacy, source or reliability, and affordability. These methods have significant advantages in terms of their simplicity and comparability, but are widely recognized to oversimplify and underestimate the global burden of household water insecurity. In contrast, a broader definition of household water insecurity should include entitlements and human capabilities, sociocultural dynamics, and political institutions and processes. This paper proposes a mix of qualitative and quantitative methods that can be widely adopted across cultural, geographic, and demographic contexts to assess hard-to-measure dimensions of household water insecurity. In doing so, it critically evaluates existing methods for assessing household water insecurity and suggests ways in which methodological innovations advance a broader definition of household water insecurity.
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Affiliation(s)
- Amber Wutich
- School of Human Evolution & Social Change and Center for Global Health, Arizona State University
| | - Jessica Budds
- School of International Development, University of East Anglia
| | | | - Jo Geere
- School of Allied Health Professions, University of East Anglia
| | - Leila Harris
- Institute for Resources, Environment and Sustainability, University of British Columbia
| | - Jennifer Horney
- Department of Epidemiology and Biostatistics, Texas A&M University
| | | | - Emma Norman
- Native Environmental Science Program, Northwest Indian College
| | | | - Amber Pearson
- Department of Geography, Environment, and Spatial Sciences, Michigan State University
| | - Sameer Shah
- Institute for Resources, Environment and Sustainability, University of British Columbia
| | - Jamie Shinn
- Department of Geology & Geography, West Virginia University
| | - Karen Simpson
- Department of Geography and Environmental Management, University of West England Bristol
| | - Chad Staddon
- Department of Geography and Environmental Management, University of West England Bristol
| | - Justin Stoler
- Department of Geography and Regional Studies, University of Miami
| | | | - Sera Young
- Department of Anthropology, Northwestern University
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Eisenbruch AB, Roney JR. The Skillful and the Stingy: Partner Choice Decisions and Fairness Intuitions Suggest Human Adaptation for a Biological Market of Cooperators. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2017. [DOI: 10.1007/s40806-017-0107-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Gurven M, Stieglitz J, Trumble B, Blackwell AD, Beheim B, Davis H, Hooper P, Kaplan H. The Tsimane Health and Life History Project: Integrating anthropology and biomedicine. Evol Anthropol 2017; 26:54-73. [PMID: 28429567 PMCID: PMC5421261 DOI: 10.1002/evan.21515] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Indexed: 12/21/2022]
Abstract
The Tsimane Health and Life History Project, an integrated bio-behavioral study of the human life course, is designed to test competing hypotheses of human life-history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a high-fertility, kin-based context lacking amenities of modern urban life (e.g. sanitation, banks, electricity). Another aim is to understand how a high pathogen burden influences health and well-being during development and adulthood. A third aim addresses how modernization shapes human life histories and sociality. Here we outline the project's goals, history, and main findings since its inception in 2002. We reflect on the implications of current findings and highlight the need for more coordinated ethnographic and biomedical study of contemporary nonindustrial populations to address broad questions that can situate evolutionary anthropology in a key position within the social and life sciences.
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Affiliation(s)
- Michael Gurven
- Department of AnthropologyUniversity of California‐Santa BarbaraSanta Barbara CA
| | | | - Benjamin Trumble
- Center for Evolution and Medicine; School of Human Evolution and Social ChangeArizona State UniversityTempeAZ
| | - Aaron D. Blackwell
- Department of AnthropologyUniversity of California‐Santa BarbaraSanta Barbara CA
| | - Bret Beheim
- Department of Human Behavior, Ecology and CultureMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
| | - Helen Davis
- Department of AnthropologyUniversity of UtahSalt Lake CityUT
| | | | - Hillard Kaplan
- Department of AnthropologyUniversity of New MexicoAlbuquerqueNM
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