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Beheim BA, Bell AV. Why cultural distance can promote - or impede - group-beneficial outcomes. EVOLUTIONARY HUMAN SCIENCES 2024; 6:e14. [PMID: 38516367 PMCID: PMC10955364 DOI: 10.1017/ehs.2024.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 12/16/2023] [Accepted: 01/16/2024] [Indexed: 03/23/2024] Open
Abstract
Quantifying the distance between cultural groups has received substantial recent interest. A key innovation, borrowed from population genetics, is the calculation of cultural FST (CFST) statistics on datasets of human culture. Measuring the variance between groups as a fraction of total variance, FST is theoretically important in additive models of cooperation. Consistent with this, recent empirical work has confirmed that high values of pairwise CFST (measuring cultural distance) strongly predict unwillingness to cooperate with strangers in coordination vignettes. As applications for CFST increase, however, there is greater need to understand its meaning in naturalistic situations beyond additive cooperation. Focusing on games with both positive and negative frequency dependence and high-diversity, mixed equilibria, we derive a simple relationship between FST and the evolution of group-beneficial traits across a broad spectrum of social interactions. Contrary to standard assumptions, this model shows why FST can have both positive and negative marginal effects on the spread of group-beneficial traits under certain realistic conditions. These results provide broader theoretical direction for empirical applications of CFST in the evolutionary study of culture.
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Affiliation(s)
- Bret Alexander Beheim
- Department of Human Behaviour, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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2
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André JB, Baumard N, Boyer P. Cultural evolution from the producers' standpoint. EVOLUTIONARY HUMAN SCIENCES 2023; 5:e25. [PMID: 37706214 PMCID: PMC10495820 DOI: 10.1017/ehs.2023.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 09/15/2023] Open
Abstract
Standard approaches to cultural evolution focus on the recipients or consumers. This does not take into account the fitness costs incurred in producing the behaviours or artefacts that become cultural, i.e. widespread in a social group. We argue that cultural evolution models should focus on these fitness costs and benefits of cultural production, particularly in the domain of 'symbolic' culture. In this approach, cultural products can be considered as a part of the extended phenotype of producers, which can affect the fitness of recipients in a positive way (through cooperation) but also in a detrimental way (through manipulation and exploitation). Taking the producers' perspective may help explain the specific features of many kinds of cultural products.
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Affiliation(s)
| | - Nicolas Baumard
- Département d'Etudes Cognitives, Ecole Normale Supérieure, Paris, France
| | - Pascal Boyer
- Department of Psychology, Washington University in St Louis, St Louis, MO, USA
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3
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Wild G, Flear VJ, Thompson GJ. A kin-selection model of fairness in heterogeneous populations. J Theor Biol 2023; 565:111469. [PMID: 36972783 DOI: 10.1016/j.jtbi.2023.111469] [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: 12/17/2022] [Revised: 03/16/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023]
Abstract
Humans and other primates exhibit pro-social preferences for fairness. These preferences are thought to be reinforced by strong reciprocity, a policy that rewards fair actors and punishes unfair ones. Theories of fairness based on strong reciprocity have been criticized for overlooking the importance of individual differences in socially heterogeneous populations. Here, we explore the evolution of fairness in a heterogeneous population. We analyse the Ultimatum Game in cases where players' roles in the game are determined by their status. Importantly, our model allows for non-random pairing of players, and so we also explore the role played by kin selection in shaping fairness. Our kin-selection model shows that, when individuals condition their behaviour on their role in the game, fairness can be understood as either altruistic or spiteful. Altruistic fairness directs resources from less valuable members of a genetic lineage to more valuable members of the same lineage, whereas spiteful fairness keeps resources away from the competitors of the actor's high-value relatives. When individuals express fairness unconditionally it can be understood as altruistic or selfish. When it is altruistic, unconditional fairness again serves to direct resources to high-value members of genetic lineages. When it is selfish, unconditional fairness simply improves an individual's own standing. Overall, we expand kin-selection based explanations for fairness to include motivations other than spite. We show, therefore, that one need not invoke strong reciprocity to explain the advantage of fairness in heterogeneous populations.
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Affiliation(s)
- Geoff Wild
- Department of Mathematics, Western University, 1151 Richmond Street, London, N6A 5B7, Ontario, Canada.
| | - Vonica J Flear
- Department of Biology, Western University, 1151 Richmond Street, London, N6A 5B7, Ontario, Canada
| | - Graham J Thompson
- Department of Biology, Western University, 1151 Richmond Street, London, N6A 5B7, Ontario, Canada
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4
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Salali GD, Uysal MS, Bozyel G, Akpinar E, Aksu A. Does social influence affect COVID-19 vaccination intention among the unvaccinated? EVOLUTIONARY HUMAN SCIENCES 2022; 4:e32. [PMID: 37588925 PMCID: PMC10426110 DOI: 10.1017/ehs.2022.29] [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] [Indexed: 11/06/2022] Open
Abstract
Conformist social influence is a double-edged sword when it comes to vaccine promotion. On the one hand, social influence may increase vaccine uptake by reassuring the hesitant about the safety and effectiveness of the vaccine; on the other hand, people may forgo the cost of vaccination when the majority is already vaccinated - giving rise to a public goods dilemma. Here, we examine whether available information on the percentage of double-vaccinated people affects COVID-19 vaccination intention among unvaccinated people in Turkey. In an online experiment, we divided participants (n = 1013) into low, intermediate and high social influence conditions, reflecting the government's vaccine promotion messages. We found that social influence did not predict COVID-19 vaccination intention, but psychological reactance and collectivism did. People with higher reactance (intolerance of others telling one what to do and being sceptical of consensus views) had lower vaccination intention, whilst people with higher collectivism (how much a person considers group benefits over individual success) had higher vaccination intention. Our findings suggest that advertising the percentage of double-vaccinated people is not sufficient to trigger a cascade of others getting themselves vaccinated. Diverse promotion strategies reflecting the heterogeneity of individual attitudes could be more effective.
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Affiliation(s)
- Gul Deniz Salali
- Department of Anthropology, University College london, 14 Taviton Street, WC1H 0BW, UK
| | - Mete Sefa Uysal
- Department of Social Psychology, Friedrich Schiller University Jena, Jena, Germany
| | - Gizem Bozyel
- Department of Psychology, Dokuz Eylul University, Izmir, Turkey
| | - Ege Akpinar
- Deparment of Political Science and International Relations, Altinbas University, Istanbul, Turkey
| | - Ayca Aksu
- Department of Psychology, MEF University, Istanbul, Turkey
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5
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Denton KK, Ram Y, Feldman MW. Conformity and content-biased cultural transmission in the evolution of altruism. Theor Popul Biol 2021; 143:52-61. [PMID: 34793823 DOI: 10.1016/j.tpb.2021.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 11/26/2022]
Abstract
The evolution of altruism has been extensively modeled under the assumption of genetic transmission, whereas the dynamics under cultural transmission are less well understood. Previous research has shown that cultural transmission can facilitate the evolution of altruism by increasing 1) the probability of adopting the altruistic phenotype, and 2) assortment between altruists. We incorporate vertical and oblique transmission, which can be conformist or anti-conformist, into models of parental care, sibling altruism, and altruism between individuals that meet assortatively. If oblique transmission is conformist, it becomes easier for altruism to invade a population of non-altruists as the probability of vertical transmission increases. If oblique transmission is anti-conformist, decreasing vertical transmission facilitates invasion by altruism in the assortative meeting model, whereas in other models, there is a trade-off: greater vertical transmission produces greater assortment among genetically related altruists, but lowers the probability of adopting altruism via anti-conformity. Compared to conditions for invasion under genetic transmission, e.g., Hamilton's rule, we show that invasion can be easier with sufficiently strong anti-conformity, and in some models, with sufficiently high assortment even if oblique transmission is conformist. We also explore invasion by an allele A that increases individuals' content bias for altruism, in the absence of other forms of cultural transmission. If costs and benefits combine additively, A invades under previously known conditions. If costs and benefits combine multiplicatively, invasion by A and by altruism become more difficult than in the corresponding additive models.
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Affiliation(s)
- Kaleda K Denton
- Department of Biology, Stanford University, Stanford, CA, 94305, United States of America.
| | - Yoav Ram
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Marcus W Feldman
- Department of Biology, Stanford University, Stanford, CA, 94305, United States of America
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6
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Currie TE, Campenni M, Flitton A, Njagi T, Ontiri E, Perret C, Walker L. The cultural evolution and ecology of institutions. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200047. [PMID: 33993755 PMCID: PMC8126459 DOI: 10.1098/rstb.2020.0047] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2021] [Indexed: 11/29/2022] Open
Abstract
Human societies are structured by what we refer to as 'institutions', which are socially created and culturally inherited proscriptions on behaviour that define roles and set expectations about social interactions. The study of institutions in several social science fields has provided many important insights that have not been fully appreciated in the evolutionary human sciences. However, such research has often lacked a shared understanding of general processes of change that shape institutional diversity across space and time. We argue that evolutionary theory can provide a useful framework for synthesizing information from different disciplines to address issues such as how and why institutions change over time, how institutional rules co-evolve with other culturally inherited traits, and the role that ecological factors might play in shaping institutional diversity. We argue that we can gain important insights by applying cultural evolutionary thinking to the study of institutions, but that we also need to expand and adapt our approaches to better handle the ways that institutions work, and how they might change over time. In this paper, we illustrate our approach by describing macro-scale empirical comparative analyses that demonstrate how evolutionary theory can be used to generate and test hypotheses about the processes that have shaped some of the major patterns we see in institutional diversity over time and across the world today. We then go on to discuss how we might usefully develop micro-scale models of institutional change by adapting concepts from game theory and agent-based modelling. We end by considering current challenges and areas for future research, and the potential implications for other areas of study and real-world applications. This article is part of the theme issue 'Foundations of cultural evolution'.
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Affiliation(s)
- Thomas E. Currie
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Marco Campenni
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Adam Flitton
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Tim Njagi
- Tegemeo Institute of Agricultural Policy and Development, Egerton University, Nairobi, Kenya
| | - Enoch Ontiri
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
- Simply Green Worldwide, Nairobi, Kenya
| | - Cedric Perret
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Lindsay Walker
- Human Behaviour and Cultural Evolution Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
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7
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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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8
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The evolution of altruism and the serial rediscovery of the role of relatedness. Proc Natl Acad Sci U S A 2020; 117:28894-28898. [PMID: 33139540 DOI: 10.1073/pnas.2013596117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The genetic evolution of altruism (i.e., a behavior resulting in a net reduction of the survival and/or reproduction of an actor to benefit a recipient) once perplexed biologists because it seemed paradoxical in a Darwinian world. More than half a century ago, W. D. Hamilton explained that when interacting individuals are genetically related, alleles for altruism can be favored by selection because they are carried by individuals more likely to interact with other individuals carrying the alleles for altruism than random individuals in the population ("kin selection"). In recent decades, a substantial number of supposedly alternative pathways to altruism have been published, leading to controversies surrounding explanations for the evolution of altruism. Here, we systematically review the 200 most impactful papers published on the evolution of altruism and identify 43 evolutionary models in which altruism evolves and where the authors attribute the evolution of altruism to a pathway other than kin selection and/or deny the role of relatedness. An analysis of these models reveals that in every case the life cycle assumptions entail local reproduction and local interactions, thereby leading to interacting individuals being genetically related. Thus, contrary to the authors' claims, Hamilton's relatedness drives the evolution to altruism in their models. The fact that several decades of investigating the evolution to altruism have resulted in the systematic and unwitting rediscovery of the same mechanism is testament to the fundamental importance of positive relatedness between actor and recipient for explaining the evolution of altruism.
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9
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Micheletti AJC. Modelling cultural selection on biological fitness to integrate social transmission and adaptive explanations for human behaviour. EVOLUTIONARY HUMAN SCIENCES 2020; 2:e10. [PMID: 37588357 PMCID: PMC10427443 DOI: 10.1017/ehs.2020.12] [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: 01/06/2023] Open
Abstract
One of the difficulties with cultural group selection theory highlighted in the review by Smith (2020, Evol. Hum. Sci., 2, e7) is its inability to separate the evolutionary effects of selection of cultural traits based on biological fitness (Cultural Selection 1) from the effects of selection based on cultural fitness (Cultural Selection 2). Confusing these two processes can hinder the integration of adaptive explanations for human behaviour, which focus on biological fitness, and cultural evolution explanations, which often focus on social transmission. Recent empirical work is starting to bridge this gap, but progress in mathematical modelling has been considerably slower. Here, I suggest that modellers can contribute to achieving this integration by further developing models of Cultural Selection 1, where behaviours are influenced by culturally inherited traits selected on the basis of their effects on biological fitness. These models should build on existing social evolution theory methods and replace genetic relatedness with cultural relatedness, that is the probability that two individuals share a cultural variant.
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Affiliation(s)
- Alberto J. C. Micheletti
- Institute for Advanced Study in Toulouse, Université Toulouse 1 Capitole, 1 esplanade de l'Université, 31080Toulouse Cedex 06, France
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10
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Truskanov N, Emery Y, Bshary R. Juvenile cleaner fish can socially learn the consequences of cheating. Nat Commun 2020; 11:1159. [PMID: 32127522 PMCID: PMC7054547 DOI: 10.1038/s41467-020-14712-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/29/2020] [Indexed: 11/09/2022] Open
Abstract
Social learning is often proposed as an important driver of the evolution of human cooperation. In this view, cooperation in other species might be restricted because it mostly relies on individually learned or innate behaviours. Here, we show that juvenile cleaner fish (Labroides dimidiatus) can learn socially about cheating consequences in an experimental paradigm that mimics cleaners' cooperative interactions with client fish. Juvenile cleaners that had observed adults interacting with model clients learned to (1) behave more cooperatively after observing clients fleeing in response to cheating; (2) prefer clients that were tolerant to cheating; but (3) did not copy adults' arbitrary feeding preferences. These results confirm that social learning can play an active role in the development of cooperative strategies in a non-human animal. They further show that negative responses to cheating can potentially shape the reputation of cheated individuals, influencing cooperation dynamics in interaction networks.
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Affiliation(s)
- Noa Truskanov
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Yasmin Emery
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | - Redouan Bshary
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
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11
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Molleman L, Gächter S. Societal background influences social learning in cooperative decision making. EVOL HUM BEHAV 2018. [DOI: 10.1016/j.evolhumbehav.2018.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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12
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Abstract
Many physical and behavioral traits in animals, including humans, are inherited both genetically and culturally. The presence of different inheritance systems affecting the same trait can result in complex evolutionary dynamics. Here, we present a general model that elucidates the distinct roles of cultural and genetic inheritance systems and their interaction in driving the evolution of complex phenotypes. In particular, we derive a Price equation that incorporates both cultural and genetic inheritance of a phenotype where the effects of genes and culture are additive. We then use this equation to investigate whether a genetically maladaptive phenotype can evolve under dual transmission. We examine the special case of altruism using an illustrative model and show that cultural selection can overcome genetic selection when the variance in culture is sufficiently high with respect to genes. We also show that the presence of cultural transmission can modify genetic selection itself, making genetic selection more favorable to a trait than under purely genetic inheritance. Last, we consider the effect of different timescales of genetic and cultural transmission. We discuss the implications of our results for understanding the evolution of important coinherited behaviors, including how our framework can be used to generate quantitative estimates of selection pressures required for a genetically maladaptive trait to evolve.
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13
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Efferson C, Vogt S. Behavioural homogenization with spillovers in a normative domain. Proc Biol Sci 2018; 285:rspb.2018.0492. [PMID: 29794048 DOI: 10.1098/rspb.2018.0492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 04/27/2018] [Indexed: 11/12/2022] Open
Abstract
The importance of culture for human social evolution hinges largely on the extent to which culture supports outcomes that would not otherwise occur. An especially controversial claim is that social learning leads groups to coalesce around group-typical behaviours and associated social norms that spill over to shape choices in asocial settings. To test this, we conducted an experiment with 878 groups of participants in 116 communities in Sudan. Participants watched a short film and evaluated the appropriate way to behave in the situation dramatized in the film. Each session consisted of an asocial condition in which participants provided private evaluations and a social condition in which they provided public evaluations. Public evaluations allowed for social learning. Across sessions, we randomized the order of the two conditions. Public choices dramatically increased the homogeneity of normative evaluations. When the social condition was first, this homogenizing effect spilled over to subsequent asocial conditions. The asocial condition when first was thus alone in producing distinctly heterogeneous groups. Altogether, information about the choices of others led participants to converge rapidly on similar normative evaluations that continued to hold sway in subsequent asocial settings. These spillovers were at least partly owing to the combined effects of conformity and self-consistency. Conformity dominated self-consistency when the two mechanisms were in conflict, but self-consistency otherwise produced choices that persisted through time. Additionally, the tendency to conform was heterogeneous. Females conformed more than males, and conformity increased with the number of other people a decision-maker observed before making her own choice.
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Affiliation(s)
- Charles Efferson
- Department of Psychology, Royal Holloway, University of London, Egham, UK .,Centre for Experimental Social Sciences, Nuffield College, University of Oxford, Oxford, UK.,Center for Child Well-Being and Development, University of Zurich, Zurich, Switzerland
| | - Sonja Vogt
- Centre for Experimental Social Sciences, Nuffield College, University of Oxford, Oxford, UK .,Centre for the Study of African Economies, University of Oxford, Oxford, UK.,Center for Child Well-Being and Development, University of Zurich, Zurich, Switzerland
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14
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Vostroknutov A, Polonio L, Coricelli G. The Role of Intelligence in Social Learning. Sci Rep 2018; 8:6896. [PMID: 29720699 PMCID: PMC5932062 DOI: 10.1038/s41598-018-25289-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/17/2018] [Indexed: 11/10/2022] Open
Abstract
Studies in cultural evolution have uncovered many types of social learning strategies that are adaptive in certain environments. The efficiency of these strategies also depends on the individual characteristics of both the observer and the demonstrator. We investigate the relationship between intelligence and the ways social and individual information is utilised to make decisions in an uncertain environment. We measure fluid intelligence and study experimentally how individuals learn from observing the choices of a demonstrator in a 2-armed bandit problem with changing probabilities of a reward. Participants observe a demonstrator with high or low fluid intelligence. In some treatments they are aware of the intelligence score of the demonstrator and in others they are not. Low fluid intelligence individuals imitate the demonstrator more when her fluid intelligence is known than when it is not. Conversely, individuals with high fluid intelligence adjust their use of social information, as the observed behaviour changes, independently of the knowledge of the intelligence of the demonstrator. We provide evidence that intelligence determines how social and individual information is integrated in order to make choices in a changing uncertain environment.
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Affiliation(s)
| | - Luca Polonio
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| | - Giorgio Coricelli
- Department of Economics, University of Southern California, California, USA
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15
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McClung JS, Placì S, Bangerter A, Clément F, Bshary R. The language of cooperation: shared intentionality drives variation in helping as a function of group membership. Proc Biol Sci 2017; 284:rspb.2017.1682. [PMID: 28931743 DOI: 10.1098/rspb.2017.1682] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/22/2017] [Indexed: 11/12/2022] Open
Abstract
While we know that the degree to which humans are able to cooperate is unrivalled by other species, the variation humans actually display in their cooperative behaviour has yet to be fully explained. This may be because research based on experimental game-theoretical studies neglects fundamental aspects of human sociality and psychology, namely social interaction and language. Using a new optimal foraging game loosely modelled on the prisoner's dilemma, the egg hunt, we categorized players as either in-group or out-group to each other and studied their spontaneous language usage while they made interactive, potentially cooperative decisions. Both shared group membership and the possibility to talk led to increased cooperation and overall success in the hunt. Notably, analysis of players' conversations showed that in-group members engaged more in shared intentionality, the human ability to both mentally represent and then adopt another's goal, whereas out-group members discussed individual goals more. Females also helped more and displayed more shared intentionality in discussions than males. Crucially, we show that shared intentionality was the mechanism driving the increase in helping between in-group players over out-group players at a cost to themselves. By studying spontaneous language during social interactions and isolating shared intentionality as the mechanism underlying successful cooperation, the current results point to a probable psychological source of the variation in cooperation humans display.
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Affiliation(s)
- Jennifer Susan McClung
- Centre for Cognitive Science, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Sarah Placì
- Centre for Cognitive Science, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Adrian Bangerter
- Centre for Cognitive Science, Institute of Work and Organizational Psychology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Fabrice Clément
- Centre for Cognitive Science, Institute of Language and Communication Sciences, University of Neuchâtel, Pierre-à-Mazel 7, 2000 Neuchâtel, Switzerland
| | - Redouan Bshary
- Centre for Cognitive Science, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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16
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Burton-Chellew MN, El Mouden C, West SA. Social learning and the demise of costly cooperation in humans. Proc Biol Sci 2017; 284:20170067. [PMID: 28446694 PMCID: PMC5413920 DOI: 10.1098/rspb.2017.0067] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/21/2017] [Indexed: 12/11/2022] Open
Abstract
Humans have a sophisticated ability to learn from others, termed social learning, which has allowed us to spread over the planet, construct complex societies, and travel to the moon. It has been hypothesized that social learning has played a pivotal role in making human societies cooperative, by favouring cooperation even when it is not favoured by genetical selection. However, this hypothesis lacks direct experimental testing, and the opposite prediction has also been made, that social learning disfavours cooperation. We experimentally tested how different aspects of social learning affect the level of cooperation in public-goods games. We found that: (i) social information never increased cooperation and usually led to decreased cooperation; (ii) cooperation was lowest when individuals could observe how successful individuals behaved; and (iii) cooperation declined because individuals preferred to copy successful individuals, who cooperated less, rather than copy common behaviours. Overall, these results suggest that individuals use social information to try and improve their own success, and that this can lead to lower levels of cooperation.
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Affiliation(s)
- Maxwell N Burton-Chellew
- Department of Zoology, the University of Oxford, Oxford OX1 3PS, UK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford, OX1 4AU, UK
| | - Claire El Mouden
- Department of Zoology, the University of Oxford, Oxford OX1 3PS, UK
| | - Stuart A West
- Department of Zoology, the University of Oxford, Oxford OX1 3PS, UK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen College, Oxford, OX1 4AU, UK
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17
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The Evolution of Facultative Conformity Based on Similarity. PLoS One 2016; 11:e0168551. [PMID: 28002461 PMCID: PMC5176289 DOI: 10.1371/journal.pone.0168551] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/02/2016] [Indexed: 11/19/2022] Open
Abstract
Conformist social learning can have a pronounced impact on the cultural evolution of human societies, and it can shape both the genetic and cultural evolution of human social behavior more broadly. Conformist social learning is beneficial when the social learner and the demonstrators from whom she learns are similar in the sense that the same behavior is optimal for both. Otherwise, the social learner's optimum is likely to be rare among demonstrators, and conformity is costly. The trade-off between these two situations has figured prominently in the longstanding debate about the evolution of conformity, but the importance of the trade-off can depend critically on the flexibility of one's social learning strategy. We developed a gene-culture coevolutionary model that allows cognition to encode and process information about the similarity between naive learners and experienced demonstrators. Facultative social learning strategies that condition on perceived similarity evolve under certain circumstances. When this happens, facultative adjustments are often asymmetric. Asymmetric adjustments mean that the tendency to follow the majority when learners perceive demonstrators as similar is stronger than the tendency to follow the minority when learners perceive demonstrators as different. In an associated incentivized experiment, we found that social learners adjusted how they used social information based on perceived similarity, but adjustments were symmetric. The symmetry of adjustments completely eliminated the commonly assumed trade-off between cases in which learners and demonstrators share an optimum versus cases in which they do not. In a second experiment that maximized the potential for social learners to follow their preferred strategies, a few social learners exhibited an inclination to follow the majority. Most, however, did not respond systematically to social information. Additionally, in the complete absence of information about their similarity to demonstrators, social learners were unwilling to make assumptions about whether they shared an optimum with demonstrators. Instead, social learners simply ignored social information even though this was the only information available. Our results suggest that social cognition equips people to use conformity in a discriminating fashion that moderates the evolutionary trade-offs that would occur if conformist social learning was rigidly applied.
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Powers ST, van Schaik CP, Lehmann L. How institutions shaped the last major evolutionary transition to large-scale human societies. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150098. [PMID: 26729937 DOI: 10.1098/rstb.2015.0098] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
What drove the transition from small-scale human societies centred on kinship and personal exchange, to large-scale societies comprising cooperation and division of labour among untold numbers of unrelated individuals? We propose that the unique human capacity to negotiate institutional rules that coordinate social actions was a key driver of this transition. By creating institutions, humans have been able to move from the default 'Hobbesian' rules of the 'game of life', determined by physical/environmental constraints, into self-created rules of social organization where cooperation can be individually advantageous even in large groups of unrelated individuals. Examples include rules of food sharing in hunter-gatherers, rules for the usage of irrigation systems in agriculturalists, property rights and systems for sharing reputation between mediaeval traders. Successful institutions create rules of interaction that are self-enforcing, providing direct benefits both to individuals that follow them, and to individuals that sanction rule breakers. Forming institutions requires shared intentionality, language and other cognitive abilities largely absent in other primates. We explain how cooperative breeding likely selected for these abilities early in the Homo lineage. This allowed anatomically modern humans to create institutions that transformed the self-reliance of our primate ancestors into the division of labour of large-scale human social organization.
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Affiliation(s)
- Simon T Powers
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
| | - Carel P van Schaik
- Anthropological Institute and Museum, University of Zürich, Zürich, Switzerland
| | - Laurent Lehmann
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
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Powers ST, Lehmann L. When is bigger better? The effects of group size on the evolution of helping behaviours. Biol Rev Camb Philos Soc 2016; 92:902-920. [PMID: 26989856 DOI: 10.1111/brv.12260] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 02/03/2016] [Accepted: 02/11/2016] [Indexed: 11/30/2022]
Abstract
Understanding the evolution of sociality in humans and other species requires understanding how selection on social behaviour varies with group size. However, the effects of group size are frequently obscured in the theoretical literature, which often makes assumptions that are at odds with empirical findings. In particular, mechanisms are suggested as supporting large-scale cooperation when they would in fact rapidly become ineffective with increasing group size. Here we review the literature on the evolution of helping behaviours (cooperation and altruism), and frame it using a simple synthetic model that allows us to delineate how the three main components of the selection pressure on helping must vary with increasing group size. The first component is the marginal benefit of helping to group members, which determines both direct fitness benefits to the actor and indirect fitness benefits to recipients. While this is often assumed to be independent of group size, marginal benefits are in practice likely to be maximal at intermediate group sizes for many types of collective action problems, and will eventually become very small in large groups due to the law of decreasing marginal returns. The second component is the response of social partners on the past play of an actor, which underlies conditional behaviour under repeated social interactions. We argue that under realistic conditions on the transmission of information in a population, this response on past play decreases rapidly with increasing group size so that reciprocity alone (whether direct, indirect, or generalised) cannot sustain cooperation in very large groups. The final component is the relatedness between actor and recipient, which, according to the rules of inheritance, again decreases rapidly with increasing group size. These results explain why helping behaviours in very large social groups are limited to cases where the number of reproducing individuals is small, as in social insects, or where there are social institutions that can promote (possibly through sanctioning) large-scale cooperation, as in human societies. Finally, we discuss how individually devised institutions can foster the transition from small-scale to large-scale cooperative groups in human evolution.
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Affiliation(s)
- Simon T Powers
- Department of Ecology and Evolution, University of Lausanne, CH-1015, Lausanne, Switzerland.,School of Computing, Edinburgh Napier University, Edinburgh, EH10 5DT, U.K
| | - Laurent Lehmann
- Department of Ecology and Evolution, University of Lausanne, CH-1015, Lausanne, Switzerland
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Henrich J, Chudek M, Boyd R. The Big Man Mechanism: how prestige fosters cooperation and creates prosocial leaders. Philos Trans R Soc Lond B Biol Sci 2015; 370:20150013. [PMID: 26503686 PMCID: PMC4633849 DOI: 10.1098/rstb.2015.0013] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2015] [Indexed: 11/16/2022] Open
Abstract
Anthropological evidence from diverse societies suggests that prestige-based leadership may provide a foundation for cooperation in many contexts. Here, inspired by such ethnographic observations and building on a foundation of existing research on the evolution of prestige, we develop a set of formal models to explore when an evolved prestige psychology might drive the cultural evolution of n-person cooperation, and how such a cultural evolutionary process might create novel selection pressures for genes that make prestigious individuals more prosocial. Our results reveal (i) how prestige can foster the cultural emergence of cooperation by generating correlated behavioural phenotypes, both between leaders and followers, and among followers; (ii) why, in the wake of cultural evolution, natural selection favours genes that make prestigious leaders more prosocial, but only when groups are relatively small; and (iii), why the effectiveness of status differences in generating cooperation in large groups depends on cultural transmission (and not primarily on deference or coercion). Our theoretical framework, and the specific predictions made by these models, sketch out an interdisciplinary research programme that cross-cuts anthropology, biology, psychology and economics. Some of our predictions find support from laboratory work in behavioural economics and are consistent with several real-world patterns.
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Affiliation(s)
- Joseph Henrich
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA 03138, USA Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, British Columbia, Canada V6S 1V9 Department of Economics, University of British Columbia, 2136 West Mall, Vancouver, British Columbia, Canada V6S 1V9 Canadian Institute for Advanced Research, 180 Dundas Street, Toronto, Ontario, Canada M5G 1Z8
| | - Maciej Chudek
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85281, USA
| | - Robert Boyd
- Canadian Institute for Advanced Research, 180 Dundas Street, Toronto, Ontario, Canada M5G 1Z8 Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85281, USA
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Tamura K, Kobayashi Y, Ihara Y. Evolution of individual versus social learning on social networks. J R Soc Interface 2015; 12:20141285. [PMID: 25631568 DOI: 10.1098/rsif.2014.1285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A number of studies have investigated the roles played by individual and social learning in cultural phenomena and the relative advantages of the two learning strategies in variable environments. Because social learning involves the acquisition of behaviours from others, its utility depends on the availability of 'cultural models' exhibiting adaptive behaviours. This indicates that social networks play an essential role in the evolution of learning. However, possible effects of social structure on the evolution of learning have not been fully explored. Here, we develop a mathematical model to explore the evolutionary dynamics of learning strategies on social networks. We first derive the condition under which social learners (SLs) are selectively favoured over individual learners in a broad range of social network. We then obtain an analytical approximation of the long-term average frequency of SLs in homogeneous networks, from which we specify the condition, in terms of three relatedness measures, for social structure to facilitate the long-term evolution of social learning. Finally, we evaluate our approximation by Monte Carlo simulations in complete graphs, regular random graphs and scale-free networks. We formally show that whether social structure favours the evolution of social learning is determined by the relative magnitudes of two effects of social structure: localization in competition, by which competition between learning strategies is evaded, and localization in cultural transmission, which slows down the spread of adaptive traits. In addition, our estimates of the relatedness measures suggest that social structure disfavours the evolution of social learning when selection is weak.
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Affiliation(s)
- Kohei Tamura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Department of Creative Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan CREST, JST, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Yutaka Kobayashi
- Department of Management, Kochi University of Technology, Tosayamada, Kami-city, Kochi 782-8502, Japan
| | - Yasuo Ihara
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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van den Berg P, Molleman L, Weissing FJ. Focus on the success of others leads to selfish behavior. Proc Natl Acad Sci U S A 2015; 112:2912-7. [PMID: 25730855 PMCID: PMC4352783 DOI: 10.1073/pnas.1417203112] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has often been argued that the spectacular cognitive capacities of humans are the result of selection for the ability to gather, process, and use information about other people. Recent studies show that humans strongly and consistently differ in what type of social information they are interested in. Although some individuals mainly attend to what the majority is doing (frequency-based learning), others focus on the success that their peers achieve with their behavior (success-based learning). Here, we show that such differences in social learning have important consequences for the outcome of social interactions. We report on a decision-making experiment in which individuals were first classified as frequency- and success-based learners and subsequently grouped according to their learning strategy. When confronted with a social dilemma situation, groups of frequency-based learners cooperated considerably more than groups of success-based learners. A detailed analysis of the decision-making process reveals that these differences in cooperation are a direct result of the differences in information use. Our results show that individual differences in social learning strategies are crucial for understanding social behavior.
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Affiliation(s)
- Pieter van den Berg
- Theoretical Biology Group, University of Groningen, 9747 AG Groningen, The Netherlands; and
| | - Lucas Molleman
- Theoretical Biology Group, University of Groningen, 9747 AG Groningen, The Netherlands; and The Centre for Decision Research and Experimental Economics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Franz J Weissing
- Theoretical Biology Group, University of Groningen, 9747 AG Groningen, The Netherlands; and
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Raihani NJ, Bshary R. Why humans might help strangers. Front Behav Neurosci 2015; 9:39. [PMID: 25750619 PMCID: PMC4335183 DOI: 10.3389/fnbeh.2015.00039] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/04/2015] [Indexed: 11/23/2022] Open
Abstract
Humans regularly help strangers, even when interactions are apparently unobserved and unlikely to be repeated. Such situations have been simulated in the laboratory using anonymous one-shot games (e.g., prisoner's dilemma) where the payoff matrices used make helping biologically altruistic. As in real-life, participants often cooperate in the lab in these one-shot games with non-relatives, despite that fact that helping is under negative selection under these circumstances. Two broad explanations for such behavior prevail. The "big mistake" or "mismatch" theorists argue that behavior is constrained by psychological mechanisms that evolved predominantly in the context of repeated interactions with known individuals. In contrast, the cultural group selection theorists posit that humans have been selected to cooperate in anonymous one-shot interactions due to strong between-group competition, which creates interdependence among in-group members. We present these two hypotheses before discussing alternative routes by which humans could increase their direct fitness by cooperating with strangers under natural conditions. In doing so, we explain why the standard lab games do not capture real-life in various important aspects. First, asymmetries in the cost of perceptual errors regarding the context of the interaction (one-shot vs. repeated; anonymous vs. public) might have selected for strategies that minimize the chance of making costly behavioral errors. Second, helping strangers might be a successful strategy for identifying other cooperative individuals in the population, where partner choice can turn strangers into interaction partners. Third, in contrast to the assumptions of the prisoner's dilemma model, it is possible that benefits of cooperation follow a non-linear function of investment. Non-linear benefits result in negative frequency dependence even in one-shot games. Finally, in many real-world situations individuals are able to parcel investments such that a one-shot interaction is turned into a repeated game of many decisions.
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Affiliation(s)
- Nichola J. Raihani
- Department of Genetics Evolution and Environment, University College LondonLondon, UK
| | - Redouan Bshary
- Institut de Biologie, Université de NeuchâtelNeuchatel, Switzerland
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Cultural group selection plays an essential role in explaining human cooperation: A sketch of the evidence. Behav Brain Sci 2014; 39:e30. [PMID: 25347943 DOI: 10.1017/s0140525x1400106x] [Citation(s) in RCA: 195] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Human cooperation is highly unusual. We live in large groups composed mostly of non-relatives. Evolutionists have proposed a number of explanations for this pattern, including cultural group selection and extensions of more general processes such as reciprocity, kin selection, and multi-level selection acting on genes. Evolutionary processes are consilient; they affect several different empirical domains, such as patterns of behavior and the proximal drivers of that behavior. In this target article, we sketch the evidence from five domains that bear on the explanatory adequacy of cultural group selection and competing hypotheses to explain human cooperation. Does cultural transmission constitute an inheritance system that can evolve in a Darwinian fashion? Are the norms that underpin institutions among the cultural traits so transmitted? Do we observe sufficient variation at the level of groups of considerable size for group selection to be a plausible process? Do human groups compete, and do success and failure in competition depend upon cultural variation? Do we observe adaptations for cooperation in humans that most plausibly arose by cultural group selection? If the answer to one of these questions is "no," then we must look to other hypotheses. We present evidence, including quantitative evidence, that the answer to all of the questions is "yes" and argue that we must take the cultural group selection hypothesis seriously. If culturally transmitted systems of rules (institutions) that limit individual deviance organize cooperation in human societies, then it is not clear that any extant alternative to cultural group selection can be a complete explanation.
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Mullon C, Lehmann L. The robustness of the weak selection approximation for the evolution of altruism against strong selection. J Evol Biol 2014; 27:2272-82. [DOI: 10.1111/jeb.12462] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/29/2014] [Accepted: 07/07/2014] [Indexed: 11/28/2022]
Affiliation(s)
- C. Mullon
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
| | - L. Lehmann
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
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Molleman L, van den Berg P, Weissing FJ. Consistent individual differences in human social learning strategies. Nat Commun 2014; 5:3570. [PMID: 24705692 DOI: 10.1038/ncomms4570] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 03/06/2014] [Indexed: 11/09/2022] Open
Abstract
Social learning has allowed humans to build up extensive cultural repertoires, enabling them to adapt to a wide variety of environmental and social conditions. However, it is unclear which social learning strategies people use, especially in social contexts where their payoffs depend on the behaviour of others. Here we show experimentally that individuals differ in their social learning strategies and that they tend to employ the same learning strategy irrespective of the interaction context. Payoff-based learners focus on their peers' success, while decision-based learners disregard payoffs and exclusively focus on their peers' past behaviour. These individual differences may be of considerable importance for cultural evolution. By means of a simple model, we demonstrate that groups harbouring individuals with different learning strategies may be faster in adopting technological innovations and can be more efficient through successful role differentiation. Our study highlights the importance of individual variation for human interactions and sheds new light on the dynamics of cultural evolution.
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Affiliation(s)
- Lucas Molleman
- 1] Theoretical Biology Group, University of Groningen, P.O. Box 11103, Groningen 9700 CC, The Netherlands [2]
| | - Pieter van den Berg
- 1] Theoretical Biology Group, University of Groningen, P.O. Box 11103, Groningen 9700 CC, The Netherlands [2]
| | - Franz J Weissing
- Theoretical Biology Group, University of Groningen, P.O. Box 11103, Groningen 9700 CC, The Netherlands
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El Mouden C, André JB, Morin O, Nettle D. Cultural transmission and the evolution of human behaviour: a general approach based on the Price equation. J Evol Biol 2013; 27:231-41. [PMID: 24329934 DOI: 10.1111/jeb.12296] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 11/07/2013] [Accepted: 11/09/2013] [Indexed: 12/01/2022]
Abstract
Transmitted culture can be viewed as an inheritance system somewhat independent of genes that is subject to processes of descent with modification in its own right. Although many authors have conceptualized cultural change as a Darwinian process, there is no generally agreed formal framework for defining key concepts such as natural selection, fitness, relatedness and altruism for the cultural case. Here, we present and explore such a framework using the Price equation. Assuming an isolated, independently measurable culturally transmitted trait, we show that cultural natural selection maximizes cultural fitness, a distinct quantity from genetic fitness, and also that cultural relatedness and cultural altruism are not reducible to or necessarily related to their genetic counterparts. We show that antagonistic coevolution will occur between genes and culture whenever cultural fitness is not perfectly aligned with genetic fitness, as genetic selection will shape psychological mechanisms to avoid susceptibility to cultural traits that bear a genetic fitness cost. We discuss the difficulties with conceptualizing cultural change using the framework of evolutionary theory, the degree to which cultural evolution is autonomous from genetic evolution, and the extent to which cultural change should be seen as a Darwinian process. We argue that the nonselection components of evolutionary change are much more important for culture than for genes, and that this and other important differences from the genetic case mean that different approaches and emphases are needed for cultural than genetic processes.
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Affiliation(s)
- C El Mouden
- Department of Zoology & Nuffield College, University of Oxford, Oxford, UK
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29
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Cultural evolution of cooperation: The interplay between forms of social learning and group selection. EVOL HUM BEHAV 2013. [DOI: 10.1016/j.evolhumbehav.2013.06.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Molleman L, Pen I, Weissing FJ. Effects of conformism on the cultural evolution of social behaviour. PLoS One 2013; 8:e68153. [PMID: 23874528 PMCID: PMC3707918 DOI: 10.1371/journal.pone.0068153] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/24/2013] [Indexed: 12/05/2022] Open
Abstract
Models of cultural evolution study how the distribution of cultural traits changes over time. The dynamics of cultural evolution strongly depends on the way these traits are transmitted between individuals by social learning. Two prominent forms of social learning are payoff-based learning (imitating others that have higher payoffs) and conformist learning (imitating locally common behaviours). How payoff-based and conformist learning affect the cultural evolution of cooperation is currently a matter of lively debate, but few studies systematically analyse the interplay of these forms of social learning. Here we perform such a study by investigating how the interaction of payoff-based and conformist learning affects the outcome of cultural evolution in three social contexts. First, we develop a simple argument that provides insights into how the outcome of cultural evolution will change when more and more conformist learning is added to payoff-based learning. In a social dilemma (e.g. a Prisoner’s Dilemma), conformism can turn cooperation into a stable equilibrium; in an evasion game (e.g. a Hawk-Dove game or a Snowdrift game) conformism tends to destabilize the polymorphic equilibrium; and in a coordination game (e.g. a Stag Hunt game), conformism changes the basin of attraction of the two equilibria. Second, we analyse a stochastic event-based model, revealing that conformism increases the speed of cultural evolution towards pure equilibria. Individual-based simulations as well as the analysis of the diffusion approximation of the stochastic model by and large confirm our findings. Third, we investigate the effect of an increasing degree of conformism on cultural group selection in a group-structured population. We conclude that, in contrast to statements in the literature, conformism hinders rather than promotes the evolution of cooperation.
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Affiliation(s)
- Lucas Molleman
- Theoretical Biology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands.
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31
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Gabora L. An evolutionary framework for cultural change: Selectionism versus communal exchange. Phys Life Rev 2013; 10:117-45. [DOI: 10.1016/j.plrev.2013.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Gabora L. WITHDRAWN: An evolutionary framework for culture and creativity: Selectionism versus communal exchange. Phys Life Rev 2012:S1571-0645(12)00052-8. [PMID: 22939689 DOI: 10.1016/j.plrev.2012.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 06/06/2012] [Indexed: 10/28/2022]
Abstract
This article has been withdrawn at the request of the Editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Abstract
The evolutionary foundations of helping among nonkin in humans have been the object of intense debates in the past decades. One thesis has had a prominent influence in this debate: the suggestion that genuine altruism, strictly defined as a form of help that comes at a net fitness cost for the benefactor, might have evolved owing to cultural transmission. The gene-culture coevolution literature is wont to claim that cultural evolution changes the selective pressures that normally act to limit the emergence of altruistic behaviours. This paper aims to recall, however, that cultural transmission yields altruism only to the extent that it relies on maladaptive mechanisms, such as conformist imitation and (in some cases) payoff-biased transmission. This point is sometimes obscured in the literature by a confusion between genuine altruism, maladaptive by definition, and mutualistic forms of cooperation, that benefit all parties in the long run. Theories of cultural altruism do not lift the selective pressures weighing on strictly altruistic actions; they merely shift the burden of maladaptation from social cognition to cultural transmission.
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Affiliation(s)
- J-B André
- CNRS UMR7206 Eco-anthropologie et ethnobiologie, MNHN, Université Paris Diderot, F75005 Paris, France.
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Abstract
Teaching, alongside imitation, is widely thought to underlie the success of humanity by allowing high-fidelity transmission of information, skills, and technology between individuals, facilitating both cumulative knowledge gain and normative culture. Yet, it remains a mystery why teaching should be widespread in human societies but extremely rare in other animals. We explore the evolution of teaching using simple genetic models in which a single tutor transmits adaptive information to a related pupil at a cost. Teaching is expected to evolve where its costs are outweighed by the inclusive fitness benefits that result from the tutor's relatives being more likely to acquire the valuable information. We find that teaching is not favored where the pupil can easily acquire the information on its own, or through copying others, or for difficult to learn traits, where teachers typically do not possess the information to pass on to relatives. This leads to a narrow range of traits for which teaching would be efficacious, which helps to explain the rarity of teaching in nature, its unusual distribution, and its highly specific nature. Further models that allow for cumulative cultural knowledge gain suggest that teaching evolved in humans because cumulative culture renders otherwise difficult-to-acquire valuable information available to teach.
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Affiliation(s)
- L Fogarty
- Centre for Social Learning and Cognitive Evolution, School of Biology, University of St Andrews, Queen's Terrace, St. Andrews, Fife, KY16 9TS, United Kingdom
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West SA, El Mouden C, Gardner A. Sixteen common misconceptions about the evolution of cooperation in humans. EVOL HUM BEHAV 2011. [DOI: 10.1016/j.evolhumbehav.2010.08.001] [Citation(s) in RCA: 306] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Beyond DNA: integrating inclusive inheritance into an extended theory of evolution. Nat Rev Genet 2011; 12:475-86. [PMID: 21681209 DOI: 10.1038/nrg3028] [Citation(s) in RCA: 360] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Many biologists are calling for an 'extended evolutionary synthesis' that would 'modernize the modern synthesis' of evolution. Biological information is typically considered as being transmitted across generations by the DNA sequence alone, but accumulating evidence indicates that both genetic and non-genetic inheritance, and the interactions between them, have important effects on evolutionary outcomes. We review the evidence for such effects of epigenetic, ecological and cultural inheritance and parental effects, and outline methods that quantify the relative contributions of genetic and non-genetic heritability to the transmission of phenotypic variation across generations. These issues have implications for diverse areas, from the question of missing heritability in human complex-trait genetics to the basis of major evolutionary transitions.
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Classes of communication and the conditions for their evolution. Theor Popul Biol 2011; 79:174-83. [DOI: 10.1016/j.tpb.2011.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 03/02/2011] [Accepted: 03/03/2011] [Indexed: 11/23/2022]
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Boyd R, Richerson PJ, Henrich J. Rapid cultural adaptation can facilitate the evolution of large-scale cooperation. Behav Ecol Sociobiol 2011; 65:431-444. [PMID: 21423337 PMCID: PMC3038225 DOI: 10.1007/s00265-010-1100-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 10/28/2010] [Accepted: 10/29/2010] [Indexed: 11/29/2022]
Abstract
Over the past several decades, we have argued that cultural evolution can facilitate the evolution of large-scale cooperation because it often leads to more rapid adaptation than genetic evolution, and, when multiple stable equilibria exist, rapid adaptation leads to variation among groups. Recently, Lehmann, Feldman, and colleagues have published several papers questioning this argument. They analyze models showing that cultural evolution can actually reduce the range of conditions under which cooperation can evolve and interpret these models as indicating that we were wrong to conclude that culture facilitated the evolution of human cooperation. In the main, their models assume that rates of cultural adaption are not strong enough compared to migration to maintain persistent variation among groups when payoffs create multiple stable equilibria. We show that Lehmann et al. reach different conclusions because they have made different assumptions. We argue that the assumptions that underlie our models are more consistent with the empirical data on large-scale cultural variation in humans than those of Lehmann et al., and thus, our models provide a more plausible account of the cultural evolution of human cooperation in large groups. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-010-1100-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robert Boyd
- Department of Anthropology, UCLA, Los Angeles, CA 90095 USA
| | - Peter J. Richerson
- Department Environmental Science and Policy and Center for Population Biology, UC Davis, Davis, CA 95616 USA
| | - Joseph Henrich
- Departments of Psychology and Economics, University of British Columbia, Vancouver, BC Canada V6T 1Z4
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Boyd R, Richerson PJ. Transmission coupling mechanisms: cultural group selection. Philos Trans R Soc Lond B Biol Sci 2011; 365:3787-95. [PMID: 21041204 DOI: 10.1098/rstb.2010.0046] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The application of phylogenetic methods to cultural variation raises questions about how cultural adaption works and how it is coupled to cultural transmission. Cultural group selection is of particular interest in this context because it depends on the same kinds of mechanisms that lead to tree-like patterns of cultural variation. Here, we review ideas about cultural group selection relevant to cultural phylogenetics. We discuss why group selection among multiple equilibria is not subject to the usual criticisms directed at group selection, why multiple equilibria are a common phenomena, and why selection among multiple equilibria is not likely to be an important force in genetic evolution. We also discuss three forms of group competition and the processes that cause populations to shift from one equilibrium to another and create a mutation-like process at the group level.
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Affiliation(s)
- Robert Boyd
- Department of Anthropology, University of California, Los Angeles, CA 90095, USA.
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Rankin DJ, Rocha EPC, Brown SP. What traits are carried on mobile genetic elements, and why? Heredity (Edinb) 2011; 106:1-10. [PMID: 20332804 PMCID: PMC3183850 DOI: 10.1038/hdy.2010.24] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 01/28/2010] [Accepted: 02/02/2010] [Indexed: 01/22/2023] Open
Abstract
Although similar to any other organism, prokaryotes can transfer genes vertically from mother cell to daughter cell, they can also exchange certain genes horizontally. Genes can move within and between genomes at fast rates because of mobile genetic elements (MGEs). Although mobile elements are fundamentally self-interested entities, and thus replicate for their own gain, they frequently carry genes beneficial for their hosts and/or the neighbours of their hosts. Many genes that are carried by mobile elements code for traits that are expressed outside of the cell. Such traits are involved in bacterial sociality, such as the production of public goods, which benefit a cell's neighbours, or the production of bacteriocins, which harm a cell's neighbours. In this study we review the patterns that are emerging in the types of genes carried by mobile elements, and discuss the evolutionary and ecological conditions under which mobile elements evolve to carry their peculiar mix of parasitic, beneficial and cooperative genes.
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Affiliation(s)
- D J Rankin
- Department of Biochemistry, University of Zürich, Zürich, Switzerland.
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Abstract
Policing is regarded as an important mechanism for maintaining cooperation in human and animal social groups. A simple model providing a theoretical overview of the coevolution of policing and cooperation has been analyzed by Frank (1995, 1996b, 2003, 2009), and this suggests that policing will evolve to fully suppress cheating within social groups when relatedness is low. Here, we relax some of the assumptions made by Frank, and investigate the consequences for policing and cooperation. First, we address the implicit assumption that the individual cost of investment into policing is reduced when selfishness dominates. We find that relaxing this assumption leads to policing being favored only at intermediate relatedness. Second, we address the assumption that policing fully recovers the loss of fitness incurred by the group owing to selfishness. We find that relaxing this assumption prohibits the evolution of full policing. Finally, we consider the impact of demography on the coevolution of policing and cooperation, in particular the role for kin competition to disfavor the evolution of policing, using both a heuristic "open" model and a "closed" island model. We find that large groups and increased kin competition disfavor policing, and that policing is maintained more readily than it invades. Policing may be harder to evolve than previously thought.
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Affiliation(s)
- Claire El Mouden
- Department of Zoology, Oxford University, South Parks Road, Oxford, OX1 3PS, United Kingdom.
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Danchin É, Wagner RH. Inclusive heritability: combining genetic and non-genetic information to study animal behavior and culture. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.17640.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Nogueira T, Rankin DJ, Touchon M, Taddei F, Brown SP, Rocha EPC. Horizontal gene transfer of the secretome drives the evolution of bacterial cooperation and virulence. Curr Biol 2009; 19:1683-91. [PMID: 19800234 PMCID: PMC2773837 DOI: 10.1016/j.cub.2009.08.056] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 08/10/2009] [Accepted: 08/20/2009] [Indexed: 01/09/2023]
Abstract
Background Microbes engage in a remarkable array of cooperative behaviors, secreting shared proteins that are essential for foraging, shelter, microbial warfare, and virulence. These proteins are costly, rendering populations of cooperators vulnerable to exploitation by nonproducing cheaters arising by gene loss or migration. In such conditions, how can cooperation persist? Results Our model predicts that differential gene mobility drives intragenomic variation in investment in cooperative traits. More mobile loci generate stronger among-individual genetic correlations at these loci (higher relatedness) and thereby allow the maintenance of more cooperative traits via kin selection. By analyzing 21 Escherichia genomes, we confirm that genes coding for secreted proteins—the secretome—are very frequently lost and gained and are associated with mobile elements. We show that homologs of the secretome are overrepresented among human gut metagenomics samples, consistent with increased relatedness at secretome loci across multiple species. The biosynthetic cost of secreted proteins is shown to be under intense selective pressure, even more than for highly expressed proteins, consistent with a cost of cooperation driving social dilemmas. Finally, we demonstrate that mobile elements are in conflict with their chromosomal hosts over the chimeric ensemble's social strategy, with mobile elements enforcing cooperation on their otherwise selfish hosts via the cotransfer of secretome genes with “mafia strategy” addictive systems (toxin-antitoxin and restriction-modification). Conclusion Our analysis matches the predictions of our model suggesting that horizontal transfer promotes cooperation, as transmission increases local genetic relatedness at mobile loci and enforces cooperation on the resident genes. As a consequence, horizontal transfer promoted by agents such as plasmids, phages, or integrons drives microbial cooperation.
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Lehmann L, Feldman MW. War and the evolution of belligerence and bravery. Proc Biol Sci 2008; 275:2877-85. [PMID: 18755675 PMCID: PMC2605837 DOI: 10.1098/rspb.2008.0842] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 08/04/2008] [Indexed: 11/12/2022] Open
Abstract
Tribal war occurs when a coalition of individuals use force to seize reproduction-enhancing resources, and it may have affected human evolution. Here, we develop a population-genetic model for the coevolution of costly male belligerence and bravery when war occurs between groups of individuals in a spatially subdivided population. Belligerence is assumed to increase an actor's group probability of trying to conquer another group. An actor's bravery is assumed to increase his group's ability to conquer an attacked group. We show that the selective pressure on these two traits can be substantial even in groups of large size, and that they may be driven by two independent reproduction-enhancing resources: additional mates for males and additional territory (or material resources) for females. This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women.
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Affiliation(s)
- Laurent Lehmann
- Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
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Lehmann L, Foster KR, Borenstein E, Feldman MW. Social and individual learning of helping in humans and other species. Trends Ecol Evol 2008; 23:664-71. [PMID: 18951656 DOI: 10.1016/j.tree.2008.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 07/08/2008] [Accepted: 07/15/2008] [Indexed: 11/17/2022]
Abstract
Helping behaviors can be innate, learned by copying others (cultural transmission) or individually learned de novo. These three possibilities are often entangled in debates on the evolution of helping in humans. Here we discuss their similarities and differences, and argue that evolutionary biologists underestimate the role of individual learning in the expression of helping behaviors in humans.
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Affiliation(s)
- Laurent Lehmann
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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The co-evolution of culturally inherited altruistic helping and cultural transmission under random group formation. Theor Popul Biol 2008; 73:506-16. [PMID: 18420241 DOI: 10.1016/j.tpb.2008.02.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 01/24/2008] [Accepted: 02/21/2008] [Indexed: 11/20/2022]
Abstract
Limited migration results in kin selective pressure on helping behaviors under a wide range of ecological, demographic and life-history situations. However, such genetically determined altruistic helping can evolve only when migration is not too strong and group size is not too large. Cultural inheritance of helping behaviors may allow altruistic helping to evolve in groups of larger size because cultural transmission has the potential to markedly decrease the variance within groups and augment the variance between groups. Here, we study the co-evolution of culturally inherited altruistic helping behaviors and two alternative cultural transmission rules for such behaviors. We find that conformist transmission, where individuals within groups tend to copy prevalent cultural variants (e.g., beliefs or values), has a strong adverse effect on the evolution of culturally inherited helping traits. This finding is at variance with the commonly held view that conformist transmission is a crucial factor favoring the evolution of altruistic helping in humans. By contrast, we find that under one-to-many transmission, where individuals within groups tend to copy a "leader" (or teacher), altruistic helping can evolve in groups of any size, although the cultural transmission rule itself hitchhikes rather weakly with a selected helping trait. Our results suggest that culturally determined helping behaviors are more likely to be driven by "leaders" than by popularity, but the emergence and stability of the cultural transmission rules themselves should be driven by some extrinsic factors.
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