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Montgomery TM, Lehmann KDS, Gregg S, Keyser K, McTigue LE, Beehner JC, Holekamp KE. Determinants of hyena participation in risky collective action. Proc Biol Sci 2023; 290:20231390. [PMID: 38018101 PMCID: PMC10685128 DOI: 10.1098/rspb.2023.1390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023] Open
Abstract
Collective action problems arise when cooperating individuals suffer costs of cooperation, while the benefits of cooperation are received by both cooperators and defectors. We address this problem using data from spotted hyenas fighting with lions. Lions are much larger and kill many hyenas, so these fights require cooperative mobbing by hyenas for them to succeed. We identify factors that predict when hyena groups engage in cooperative fights with lions, which individuals choose to participate and how the benefits of victory are distributed among cooperators and non-cooperators. We find that cooperative mobbing is better predicted by lower costs (no male lions, more hyenas) than higher benefits (need for food). Individual participation is facilitated by social factors, both over the long term (close kin, social bond strength) and the short term (greeting interactions prior to cooperation). Finally, we find some direct benefits of participation: after cooperation, participants were more likely to feed at contested carcasses than non-participants. Overall, these results are consistent with the hypothesis that, when animals face dangerous cooperative dilemmas, selection favours flexible strategies that are sensitive to dynamic factors emerging over multiple time scales.
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Affiliation(s)
- Tracy M. Montgomery
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
- Department for the Ecology of Animal Societies, Max Planck Institute for Animal Behavior, Bücklestraße 5a, 78467 Konstanz, Germany
- Center for the Advanced Study of Collective Behavior, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - Kenna D. S. Lehmann
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Human Biology Program, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
| | - Samantha Gregg
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Kathleen Keyser
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Leah E. McTigue
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Rocky Mountain Research Station, Colorado State University, 240 W Prospect St, Fort Collins, CO 80525, USA
| | - Jacinta C. Beehner
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
- Department of Anthropology, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109, USA
| | - Kay E. Holekamp
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
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2
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Samuni L, Surbeck M. Cooperation across social borders in bonobos. Science 2023; 382:805-809. [PMID: 37972165 DOI: 10.1126/science.adg0844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 09/29/2023] [Indexed: 11/19/2023]
Abstract
Cooperation beyond familial and group boundaries is core to the functioning of human societies, yet its evolution remains unclear. To address this, we examined grooming, coalition, and food-sharing patterns in bonobos (Pan paniscus), one of our closest living relatives whose rare out-group tolerance facilitates interaction opportunities between groups. We show that, as in humans, positive assortment supports bonobo cooperation across borders. Bonobo cooperative attitudes toward in-group members informed their cooperative relationships with out-groups, in particular, forming connections with out-group individuals who also exhibited high cooperation tendencies. Our findings show that cooperation between unrelated individuals across groups without immediate payoff is not exclusive to humans and suggest that such cooperation can emerge in the absence of social norms or strong cultural dispositions.
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Affiliation(s)
- Liran Samuni
- Cooperative Evolution Lab, German Primate Center, Göttingen, Germany
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Martin Surbeck
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Lemoine SRT, Samuni L, Crockford C, Wittig RM. Chimpanzees make tactical use of high elevation in territorial contexts. PLoS Biol 2023; 21:e3002350. [PMID: 37917608 PMCID: PMC10621857 DOI: 10.1371/journal.pbio.3002350] [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: 09/20/2022] [Accepted: 09/26/2023] [Indexed: 11/04/2023] Open
Abstract
Tactical warfare is considered a driver of the evolution of human cognition. One such tactic, considered unique to humans, is collective use of high elevation in territorial conflicts. This enables early detection of rivals and low-risk maneuvers, based on information gathered. Whether other animals use such tactics is unknown. With a unique dataset of 3 years of simultaneous behavioral and ranging data on 2 neighboring groups of western chimpanzees, from the Taï National Park, Côte d'Ivoire, we tested whether chimpanzees make decisions consistent with tactical use of topography to gain an advantage over rivals. We show that chimpanzees are more likely to use high hills when traveling to, rather than away from, the border where conflict typically takes place. Once on border hills, chimpanzees favor activities that facilitate information gathering about rivals. Upon leaving hills, movement decisions conformed with lowest risk engagement, indicating that higher elevation facilitates the detection of rivals presence or absence. Our results support the idea that elevation use facilitated rival information gathering and appropriate tactical maneuvers. Landscape use during territorial maneuvers in natural contexts suggests chimpanzees seek otherwise inaccessible information to adjust their behavior and points to the use of sophisticated cognitive abilities, commensurate with selection for cognition in species where individuals gain benefits from coordinated territorial defense. We advocate territorial contexts as a key paradigm for unpicking complex animal cognition.
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Affiliation(s)
- Sylvain R. T. Lemoine
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Archaeology, University of Cambridge, Cambridge, United Kingdom
| | - Liran Samuni
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Cooperative Evolution Lab, German Primate Center, Göttingen, Germany
| | - Catherine Crockford
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Ape Social Mind Lab, Institut of Cognitive Science Marc Jeannerod, UMR5229, CNRS, Lyon, France
| | - Roman M. Wittig
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Ape Social Mind Lab, Institut of Cognitive Science Marc Jeannerod, UMR5229, CNRS, Lyon, France
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Sauciuc GA, Persson T. Empirical challenges from the comparative and developmental literature to the Shared Intentionality Theory - a review of alternative data on recursive mind reading, prosociality, imitation and cumulative culture. Front Psychol 2023; 14:1157137. [PMID: 37901066 PMCID: PMC10613111 DOI: 10.3389/fpsyg.2023.1157137] [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: 02/02/2023] [Accepted: 09/28/2023] [Indexed: 10/31/2023] Open
Abstract
Humans have an irresistible inclination to coordinate actions with others, leading to species-unique forms of cooperation. According to the highly influential Shared Intentionality Theory (SITh), human cooperation is made possible by shared intentionality (SI), typically defined as a suite of socio-cognitive and motivational traits for sharing psychological states with others, thereby enabling individuals to engage in joint action in the mutually aware pursuit of shared goals. SITh theorises that SI evolved as late as 400,000 years ago, when our ancestors (in particular, Homo heidelbergensis) turned to a kind of food procurement that obligatorily required joint coordinated action. SI is, thus, hypothesized to be absent in other extant species, including our closest genetic relatives, the nonhuman great apes ("apes"). According to SITh, ape psychology is exclusively driven by individualistic motivations, as opposed to human psychology which is uniquely driven by altruistic motivations. The evolutionary scenario proposed by SITh builds on a series of findings from socio-cognitive research with apes and human children, and on the assumption that abilities expressed early in human development are human universals, unlikely to have been shaped by socio-cultural influences. Drawing on the primatological and developmental literature, we provide a systematic - albeit selective - review of SITh-inconsistent findings concerning psychological and behavioural traits theorised to be constitutive of SI. The findings we review pertain to all three thematic clusters typically addressed in SITh: (i) recursive mind reading; (ii) prosociality; (iii) imitation and cumulative culture. We conclude that such alternative data undermine two core SITh claims: the late evolutionary emergence of SI and the radical divide between ape and human psychology. We also discuss several conceptual and methodological limitations that currently hamper reliable comparative research on SI, in particular those engendered by Western-centric biases in the social sciences, where an overreliance on Western samples has promoted the formulation of Western-centric conceptualisations, operationalisations and methodologies.
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Maffezzini N, Turner SP, Bolhuis JE, Arnott G, Camerlink I. Third-party intervention and post-conflict behaviour in agonistic encounters of pigs (Sus scrofa). Front Zool 2023; 20:28. [PMID: 37592308 PMCID: PMC10433626 DOI: 10.1186/s12983-023-00508-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 08/08/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND Third-party interference in agonistic contests entails a deliberate intervention in an ongoing fight by a bystanding individual (third party) and may be followed by post-conflict social behaviour to provide support to a specific individual. The mechanisms behind third-party intervention are, however, still largely understudied. The aim of this study was to investigate third-party interference, with the predictions that (1) the interferer derives benefits from its action by winning a fight, (2) that patterns of intervention depend on familiarity, (3) that dyadic fights last longer than triadic fights, and (4) that interferers engage in non-agonistic social behaviours afterwards. Pre-pubertal pigs (Sus scrofa) (n = 384) were grouped with one familiar and four unfamiliar conspecifics (all non-kin) to elicit contests for dominance rank. Third-party interference was analysed for the first 30 min after grouping, along with the behaviour (nosing or aggression), contest duration, contest outcome, and interferer behaviour after the fight (post-conflict social behaviour). RESULTS Three types of interference were observed: non-agonistic involvement (nose contact) by the interferer in a dyadic fight; a triadic fight with each of three contestants fighting one opponent at a time; and triadic fights with two opponents jointly attacking the third one (two-against-one fights). The likelihood of a third-party intervention to occur did not depend on the presence of a familiar animal in the fight. However, once intervention was triggered, interferers attacked unfamiliar fight initiators more than familiar ones. Two-against-one fights lasted longer than other triadic fights and occurred more often when both initial contestants were females. Results of 110 triadic fights (out of 585 fights in total) revealed that interferers were more likely to win compared to the initial opponents at equal body weight. The most common post-conflict behaviour displayed by the interferer was agonistic behaviour towards another group member, independently of familiarity. CONCLUSIONS The general lack of discrimination for familiarity suggests interference is not driven by support to familiar individuals in pigs. The results show that intervening in an ongoing fight gives the interferer a high chance of contest success and may be a strategy that is beneficial to the interferer to increase its dominance status.
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Affiliation(s)
- Nicole Maffezzini
- Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, Poland
- Animal Behaviour and Welfare, Animal and Veterinary Sciences Department, Scotland's Rural College (SRUC), West Mains Rd., Edinburgh, EH9 3JG, UK
| | - Simon P Turner
- Animal Behaviour and Welfare, Animal and Veterinary Sciences Department, Scotland's Rural College (SRUC), West Mains Rd., Edinburgh, EH9 3JG, UK
| | - J Elizabeth Bolhuis
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen University and Research, Wageningen, The Netherlands
| | - Gareth Arnott
- Institute for Global Food Security, School of Biological Sciences, Queen's University, Belfast, BT9 7BL, UK.
| | - Irene Camerlink
- Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzębiec, Poland
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Mouginot M, Cheng L, Wilson ML, Feldblum JT, Städele V, Wroblewski EE, Vigilant L, Hahn BH, Li Y, Gilby IC, Pusey AE, Surbeck M. Reproductive inequality among males in the genus Pan. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220301. [PMID: 37381849 DOI: 10.1098/rstb.2022.0301] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/21/2023] [Indexed: 06/30/2023] Open
Abstract
Reproductive inequality, or reproductive skew, drives natural selection, but has been difficult to assess, particularly for males in species with promiscuous mating and slow life histories, such as bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Although bonobos are often portrayed as more egalitarian than chimpanzees, genetic studies have found high male reproductive skew in bonobos. Here, we discuss mechanisms likely to affect male reproductive skew in Pan, then re-examine skew patterns using paternity data from published work and new data from the Kokolopori Bonobo Reserve, Democratic Republic of Congo and Gombe National Park, Tanzania. Using the multinomial index (M), we found considerable overlap in skew between the species, but the highest skew occurred among bonobos. Additionally, for two of three bonobo communities, but no chimpanzee communities, the highest ranking male had greater siring success than predicted by priority-of-access. Thus, an expanded dataset covering a broader demographic range confirms that bonobos have high male reproductive skew. Detailed comparison of data from Pan highlights that reproductive skew models should consider male-male dynamics including the effect of between-group competition on incentives for reproductive concessions, but also female grouping patterns and factors related to male-female dynamics including the expression of female choice. This article is part of the theme issue 'Evolutionary ecology of inequality'.
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Affiliation(s)
- Maud Mouginot
- Department of Anthropology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Leveda Cheng
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Michael L Wilson
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
- Institute on the Environment, University of Minnesota, Saint Paul, MN 55108, USA
| | - Joseph T Feldblum
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Veronika Städele
- School of Human Evolution and Social Change, and Institute of Human Origins, Arizona State University, Tempe, AZ 85287, USA
- Cognitive Ethology Laboratory, German Primate Center, Göttingen 37077, Germany
| | - Emily E Wroblewski
- Department of Anthropology, Washington University in St Louis, St Louis, MO 63130, USA
| | - Linda Vigilant
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Beatrice H Hahn
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingying Li
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ian C Gilby
- School of Human Evolution and Social Change, and Institute of Human Origins, Arizona State University, Tempe, AZ 85287, USA
| | - Anne E Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Martin Surbeck
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
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7
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Sandel AA. Male-male relationships in chimpanzees and the evolution of human pair bonds. Evol Anthropol 2023; 32:185-194. [PMID: 37269494 DOI: 10.1002/evan.21986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/27/2022] [Accepted: 05/12/2023] [Indexed: 06/05/2023]
Abstract
The evolution of monogamy has been a central question in biological anthropology. An important avenue of research has been comparisons across "socially monogamous" mammals, but such comparisons are inappropriate for understanding human behavior because humans are not "pair living" and are only sometimes "monogamous." It is the "pair bond" between reproductive partners that is characteristic of humans and has been considered unique to our lineage. I argue that pair bonds have been overlooked in one of our closest living relatives, chimpanzees. These pair bonds are not between mates but between male "friends" who exhibit enduring and emotional social bonds. The presence of such bonds in male-male chimpanzees raises the possibility that pair bonds emerged earlier in our evolutionary history. I suggest pair bonds first arose as "friendships" and only later, in the human lineage, were present between mates. The mechanisms for these bonds were co-opted for male-female bonds in humans.
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Affiliation(s)
- Aaron A Sandel
- Department of Anthropology, University of Texas at Austin, Austin, Texas, USA
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Engelmann JM, Völter CJ, Goddu MK, Call J, Rakoczy H, Herrmann E. Chimpanzees prepare for alternative possible outcomes. Biol Lett 2023; 19:20230179. [PMID: 37340809 PMCID: PMC10282584 DOI: 10.1098/rsbl.2023.0179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023] Open
Abstract
When facing uncertainty, humans often build mental models of alternative outcomes. Considering diverging scenarios allows agents to respond adaptively to different actual worlds by developing contingency plans (covering one's bases). In a pre-registered experiment, we tested whether chimpanzees (Pan troglodytes) prepare for two mutually exclusive possibilities. Chimpanzees could access two pieces of food, but only if they successfully protected them from a human competitor. In one condition, chimpanzees could be certain about which piece of food the human experimenter would attempt to steal. In a second condition, either one of the food rewards was a potential target of the competitor. We found that chimpanzees were significantly more likely to protect both pieces of food in the second relative to the first condition, raising the possibility that chimpanzees represent and prepare effectively for different possible worlds.
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Affiliation(s)
- Jan M. Engelmann
- Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650, USA
| | - Christoph J. Völter
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, 1210 Vienna, Austria
| | - Mariel K. Goddu
- Department of Psychology, Harvard University, Cambridge, MA 02138, USA
| | - Josep Call
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9AJ, UK
| | - Hannes Rakoczy
- Department of Developmental Psychology, Georg-Elias Müller Institute of Psychology, University of Göttingen, 37073 Göttingen, Germany
| | - Esther Herrmann
- Department of Psychology, University of Portsmouth, Portsmouth PO1 2UP, UK
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Sarkar A, Wrangham RW. Evolutionary and neuroendocrine foundations of human aggression. Trends Cogn Sci 2023; 27:468-493. [PMID: 37003880 DOI: 10.1016/j.tics.2023.02.003] [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: 11/13/2022] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 04/03/2023]
Abstract
Humans present a behavioural paradox: they are peaceful in many circumstances, but they are also violent and kill conspecifics at high rates. We describe a social evolutionary theory to resolve this paradox. The theory interprets human aggression as a combination of low propensities for reactive aggression and coercive behaviour and high propensities for some forms of proactive aggression (especially coalitionary proactive aggression). These tendencies are associated with the evolution of groupishness, self-domestication, and social norms. This human aggression profile is expected to demand substantial plasticity in the evolved biological mechanisms responsible for aggression. We discuss the contributions of various social signalling molecules (testosterone, cortisol, oxytocin, vasopressin, serotonin, and dopamine) as the neuroendocrine foundation conferring such plasticity.
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Affiliation(s)
- Amar Sarkar
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.
| | - Richard W Wrangham
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
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Chimpanzee communities differ in their inter- and intrasexual social relationships. Learn Behav 2023; 51:48-58. [PMID: 36725763 PMCID: PMC9971155 DOI: 10.3758/s13420-023-00570-8] [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] [Accepted: 01/05/2023] [Indexed: 02/03/2023]
Abstract
Male and female human social bonding strategies are culturally shaped, in addition to being genetically rooted. Investigating nonhuman primate bonding strategies across sex groups allows researchers to assess whether, as with humans, they are shaped by the social environment or whether they are genetically predisposed. Studies of wild chimpanzees show that in some communities males have strong bonds with other males, whereas in others, females form particularly strong intrasex bonds, potentially indicative of cultural differences across populations. However, excluding genetic or ecological explanations when comparing different wild populations is difficult. Here, we applied social network analysis to examine male and female social bonds in two neighbouring semiwild chimpanzee groups of comparable ecological conditions and subspecies compositions, but that differ in demographic makeup. Results showed differences in bonding strategies across the two groups. While female-female party co-residence patterns were significantly stronger in Group 1 (which had an even distribution of males and females) than in Group 2 (which had a higher proportion of females than males), there were no such differences for male-male or male-female associations. Conversely, female-female grooming bonds were stronger in Group 2 than in Group 1. We also found that, in line with captive studies but contrasting research with wild chimpanzees, maternal kinship strongly predicted proximity and grooming patterns across the groups. Our findings suggest that, as with humans, male and female chimpanzee social bonds are influenced by the specific social group they live in, rather than predisposed sex-based bonding strategies.
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Qian J, Zhang T, Sun X, Chai Y. The coordination of collective and individual solutions in risk-resistant scenarios. THE EUROPEAN PHYSICAL JOURNAL. B 2023; 96:21. [PMID: 36852005 PMCID: PMC9947898 DOI: 10.1140/epjb/s10051-023-00487-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
ABSTRACT Human societies are constantly coping with global risks. In the face of these risks, people typically have two options, that is, to respond together as a whole (collective solution) or to respond independently (individual solution). Based on these two solutions, individuals have a variety of behavioral strategies. On the other hand, various regulatory bodies supported by the population limit people's choices and punish individuals who do not contribute to collective solutions. So with different risks, how do the two solutions, the various individual strategies, and the constraints from regulators affect the group's response to risk? This paper proposes an extended public goods game model involving opportunists and the regulator to explore the effectiveness of collective and individual solutions against risks. The results show that requiring individuals to invest more in the collective solution reduces the group' s success in resisting risk. To improve the group's ability to resist risk, investment in individual solution should be at least no less than that in collective solution. The establishment fund and punishment intensity of the regulatory agency have no significant effect on the success of collective and individual solutions. This inspires us to contemplate the role and measures of various types of authorities in coping with global risks.
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Affiliation(s)
- Jun Qian
- Department of Automation, Tsinghua University, 100084 Beijing, China
| | - Tongda Zhang
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Xiao Sun
- Department of Automation, Tsinghua University, 100084 Beijing, China
| | - Yueting Chai
- Department of Automation, Tsinghua University, 100084 Beijing, China
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12
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Impact of social reward on the evolution of cooperation in voluntary prisoner's dilemma. Biosystems 2023; 223:104821. [PMID: 36464161 DOI: 10.1016/j.biosystems.2022.104821] [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: 09/26/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
The existence and sustainability of cooperation is a critical issue in nature and social systems. Reward is an essential mechanism to enhance cooperation. Meanwhile, some individuals loathe competition and then choose to escape and become a loner in competition. In this scenario, we propose a four-strategy networked evolutionary game model involving rewarders, loners, cooperators, and defectors. The classical square lattice and the Erdös-Rényi random network are adopted to describe the interaction between individuals. The four-strategy model is an extension of the classic prisoner's dilemma game model. The simulation results show that the introduction of new strategic choices can significantly improve cooperation in the population. The promotion level of cooperation is directly correlated with reward intensity and negatively correlated with reward cost. With regard to the evolution of altruistic behaviors, the fixed income from interactions with loners has an impact that is connected to the temptation to defect. Furthermore, by analyzing characteristic snapshots of four strategies, we further dissect the essence of the evolution of cooperation. As the temptation value increases, cooperators and rewarders first form compact clusters, then more and more loners join to resist the intrusion of defectors. Eventually, the three strategies coexist stably in a spatially structured population. Our research may shed some light on exploring the nature of cooperation and solving social dilemmas in the future.
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13
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Puberty initiates a unique stage of social learning and development prior to adulthood: Insights from studies of adolescence in wild chimpanzees. Dev Cogn Neurosci 2022; 58:101176. [PMID: 36427434 PMCID: PMC9699942 DOI: 10.1016/j.dcn.2022.101176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/28/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022] Open
Abstract
In humans, puberty initiates a period of rapid growth, change, and formative neurobehavioral development. Brain and behavior changes during this maturational window contribute to opportunities for social learning. Here we provide new insights into adolescence as a unique period of social learning and development by describing field studies of our closest living relatives, chimpanzees. Like humans, chimpanzees have a multiyear juvenile life stage between weaning and puberty onset followed by a multiyear adolescent life stage after pubertal onset but prior to socially-recognized adulthood. As they develop increasing autonomy from caregivers, adolescent chimpanzees explore and develop many different types of social relationships with a wide range of individuals in a highly flexible social environment. We describe how adolescent social motivations and experiences differ from those of juveniles and adults and expose adolescents to high levels of uncertainty, risk, and vulnerability, as well as opportunities for adaptive social learning. We discuss how these adolescent learning experiences may be shaped by early life and in turn shape varied adult social outcomes. We outline how future chimpanzee field research can contribute in new ways to a more integrative interdisciplinary understanding of adolescence as a developmental window of adaptive social learning and resilience.
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Williams L, Shultz S, Jensen K. The primate workplace: Cooperative decision-making in human and non-human primates. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.887187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success of group foraging in primates is not only determined by ecological and social factors. It is also influenced by cognition. Group foraging success is constrained, for instance, by the challenges of coordination, synchrony and decision-making, and it is enhanced by the ability to share, learn from others and coordinate actions. However, what we currently know about the cognition of individuals in groups comes primarily from experiments on dyads, and what we know of the effect of ecological factors on group dynamics comes from larger wild groups. Our current knowledge of primate group behaviour is thus incomplete. In this review, we identify a gap in our knowledge of primate group dynamics between the dyadic studies on primate cooperation and the large group observational studies of behavioural ecology. We highlight the potential for controlled experimental studies on coordination and cooperation in primate groups. Currently, these exist primarily as studies of dyads, and these do not go far enough in testing limits of group-level behaviours. Controlled studies on primate groups beyond the dyad would be highly informative regarding the bounds of non-human primate collaboration. We look to the literature on how humans behave in groups, specifically from organisational psychology, draw parallels between human and non-human group dynamics and highlight approaches that could be applied across disciplines. Organisational psychology is explicitly concerned with the interactions between individuals in a group and the emergent properties at the group-level of these decisions. We propose that some of the major shortfalls in our understanding of primate social cognition and group dynamics can be filled by using approaches developed by organisational psychologists, particularly regarding the effects of group size and composition on group-level cooperation. To illustrate the potential applications, we provide a list of research questions drawn from organisational psychology that could be applied to non-human primates.
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15
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The influence of burial depth on germination and establishment of seeds in chimpanzee faeces, Taï National Park, Côte d’Ivoire. JOURNAL OF TROPICAL ECOLOGY 2022. [DOI: 10.1017/s0266467422000402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract
One of the many ecosystem services provided by dung beetles is that of secondary seed dispersal. This paper experimentally evaluates the effectiveness of this service using the chimpanzee–dung beetle seed dispersal system in Taï National Park, Côte d’Ivoire. The study focussed on the germination rate and success of four species of seeds contained in the faeces of Pan troglodytes verus: Dacryodes klaineana (Pierre) H.J. Lam, Diospyros mannii Hiern, Pycnanthus angolensis (Welw.) Warb., and Uapaca guineensis Muell. Arg. For each species, 600 seeds, half from chimpanzee faeces and half from mother trees, were sown in nurseries at depths of 0, 2, 5, 10, and 15 cm (i.e. 120 seeds per depth; 60 from chimp and 60 from mother trees). After germination, only the seeds of Uapaca guineensis and Diospyros mannii sown at 2 and 5 cm had a >14% rate (between 14.2 and 30.8%) of germination and seedling establishment, regardless of seed origin. An increase in the depth of seed burial appears to negatively affect the probability of seedling emergence and establishment. This study shows that dung beetles have positive impacts on seed fate. However, for these plant species, the chimpanzee’s role is limited to that of primary seed dispersal.
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16
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Brooks J, Yamamoto S. The evolution of group-mindedness: comparative research on top-down and bottom-up group cooperation in bonobos and chimpanzees. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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17
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Barrault C, Soldati A, Hobaiter C, Mugisha S, De Moor D, Zuberbühler K, Dezecache G. Thermal imaging reveals social monitoring during social feeding in wild chimpanzees. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210302. [PMID: 35934961 PMCID: PMC9358323 DOI: 10.1098/rstb.2021.0302] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Understanding the affective lives of animals has been a long-standing challenge in science. Recent technological progress in infrared thermal imaging has enabled researchers to monitor animals' physiological states in real-time when exposed to ecologically relevant situations, such as feeding in the company of others. During social feeding, an individual's physiological states are likely to vary with the nature of the resource and perceptions of competition. Previous findings in chimpanzees have indicated that events perceived as competitive cause decreases in nasal temperatures, whereas the opposite was observed for cooperative interactions. Here, we tested how food resources and audience structure impacted on how social feeding events were perceived by wild chimpanzees. Overall, we found that nasal temperatures were lower when meat was consumed as compared to figs, consistent with the idea that social feeding on more contested resources is perceived as more dangerous and stressful. Nasal temperatures were significant affected by interactions between food type and audience composition, in particular the number of males, their dominance status, and their social bond status relative to the subject, while no effects for the presence of females were observed. Our findings suggest that male chimpanzees closely monitor and assess their social environment during competitive situations, and that infrared imaging provides an important complement to access psychological processes beyond observable social behaviours. This article is part of the theme issue ‘Cognition, communication and social bonds in primates’.
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Affiliation(s)
- Claire Barrault
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Budongo Conservation Field Station, Masindi, Uganda
| | - Adrian Soldati
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Budongo Conservation Field Station, Masindi, Uganda.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Catherine Hobaiter
- Budongo Conservation Field Station, Masindi, Uganda.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | | | - Delphine De Moor
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | - Klaus Zuberbühler
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Budongo Conservation Field Station, Masindi, Uganda.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Guillaume Dezecache
- Budongo Conservation Field Station, Masindi, Uganda.,Université Clermont Auvergne, LAPSCO CNRS, Clermont-Ferrand, France
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18
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Qian J, Sun X, Zhang T, Chai Y. Authority or Autonomy? Exploring Interactions between Central and Peer Punishments in Risk-Resistant Scenarios. ENTROPY (BASEL, SWITZERLAND) 2022; 24:1289. [PMID: 36141176 PMCID: PMC9497953 DOI: 10.3390/e24091289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Game theory provides a powerful means to study human cooperation and better understand cooperation-facilitating mechanisms in general. In classical game-theoretic models, an increase in group cooperation constantly increases people's gains, implying that individual gains are a continuously varying function of the cooperation rate. However, this is inconsistent with the increasing number of risk-resistant scenarios in reality. A risk-resistant scenario means once a group does not successfully resist the risk, all individuals lose their resources, such as a community coping with COVID-19 and a village resisting a flood. In other words, individuals' gains are segmented about the collaboration rate. This paper builds a risk-resistant model to explore whether punishment still promotes collaboration when people resist risk. The results show that central and peer punishments can both encourage collaboration but with different characteristics under different risk-resistant scenarios. Specifically, central punishment constrains the collaboration motivated by peer punishment regardless of risk, while peer punishment limits the collaboration induced by central punishment only when the risk is high. Our findings provide insights into the balance between peer punishment from public autonomy and central punishment from central governance, and the proposed model paves the way for the development of richer risk-resistant models.
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Affiliation(s)
- Jun Qian
- National Engineering Laboratory for E-Commerce Technologies, Department of Automation, Tsinghua University, Beijing 100084, China
| | - Xiao Sun
- National Engineering Laboratory for E-Commerce Technologies, Department of Automation, Tsinghua University, Beijing 100084, China
| | - Tongda Zhang
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yueting Chai
- National Engineering Laboratory for E-Commerce Technologies, Department of Automation, Tsinghua University, Beijing 100084, China
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19
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Badihi G, Bodden K, Zuberbühler K, Samuni L, Hobaiter C. Flexibility in the social structure of male chimpanzees ( Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220904. [PMID: 36177197 PMCID: PMC9515636 DOI: 10.1098/rsos.220904] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Individuals of social species experience competitive costs and social benefits of group living. Substantial flexibility in humans' social structure and the combination of different types of social structure with fission-fusion dynamics allow us to live in extremely large groups-overcoming some of the costs of group living while capitalizing on the benefits. Non-human species also show a range of social strategies to deal with this trade-off. Chimpanzees are an archetypical fission-fusion species, using dynamic changes in day-to-day association to moderate the costs of within-group competition. Using 4 years of association data from two neighbouring communities of East African chimpanzees (Pan troglodytes schweinfurthii), we describe an unexplored level of flexibility in chimpanzee social structure. We show that males from the larger Waibira community (N = 24-31) exhibited additional structural levels of semi-stable core-periphery society, while males from the smaller Sonso community (N = 10-13) did not. This novel core-periphery pattern adds to previous results describing alternative modular social structure in other large communities of chimpanzees. Our data support the hypothesis that chimpanzees can incorporate a range of strategies in addition to fission-fusion to overcome costs of social living, and that their social structures may be closer to that of modern humans than previously described.
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Affiliation(s)
- Gal Badihi
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
| | - Kelsey Bodden
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
| | - Klaus Zuberbühler
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- School of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Budongo Conservation Field Station, Masindi, Uganda
| | - Liran Samuni
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Catherine Hobaiter
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- Budongo Conservation Field Station, Masindi, Uganda
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20
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Characterization of Pan social systems reveals in-group/out-group distinction and out-group tolerance in bonobos. Proc Natl Acad Sci U S A 2022; 119:e2201122119. [PMID: 35727986 DOI: 10.1073/pnas.2201122119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human between-group interactions are highly variable, ranging from violent to tolerant and affiliative. Tolerance between groups is linked to our unique capacity for large-scale cooperation and cumulative culture, but its evolutionary origins are understudied. In chimpanzees, one of our closest living relatives, predominantly hostile between-group interactions impede cooperation and information flow across groups. In contrast, in our other closest living relative, the bonobo, tolerant between-group associations are observed. However, as these associations can be frequent and prolonged and involve social interactions that mirror those within groups, it is unclear whether these bonobos really do belong to separate groups. Alternatively, the bonobo grouping patterns may be homologous to observations from the large Ngogo chimpanzee community, where individuals form within-group neighborhoods despite sharing the same membership in the larger group. To characterize bonobo grouping patterns, we compare the social structure of the Kokolopori bonobos with the chimpanzee group of Ngogo. Using cluster analysis, we find temporally stable clusters only in bonobos. Despite the large spatial overlap and frequent interactions between the bonobo clusters, we identified significant association preference within but not between clusters and a unique space use of each cluster. Although bonobo associations are flexible (i.e., fission-fusion dynamics), cluster membership predicted the bonobo fission compositions and the spatial cohesion of individuals during encounters. These findings suggest the presence of a social system that combines clear in-group/out-group distinction and out-group tolerance in bonobos, offering a unique referential model for the evolution of tolerant between-group interactions in humans.
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21
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Harrison RA, van de Waal E. The unique potential of field research to understand primate social learning and cognition. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Morris-Drake A, Kennedy P, Braga Goncalves I, Radford AN. Variation between species, populations, groups and individuals in the fitness consequences of out-group conflict. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210148. [PMID: 35369741 PMCID: PMC8977661 DOI: 10.1098/rstb.2021.0148] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Out-group conflict is rife in the natural world, occurring from primates to ants. Traditionally, research on this aspect of sociality has focused on the interactions between groups and their conspecific rivals, investigating contest function and characteristics, which group members participate and what determines who wins. In recent years, however, there has been increasing interest in the consequences of out-group conflict. In this review, we first set the scene by outlining the fitness consequences that can arise immediately to contest participants, as well as a broader range of delayed, cumulative and third-party effects of out-group conflict on survival and reproductive success. For the majority of the review, we then focus on variation in these fitness consequences of out-group conflict, describing known examples both between species and between populations, groups and individuals of the same species. Throughout, we suggest possible reasons for the variation, provide examples from a diverse array of taxa, and suggest what is needed to advance this burgeoning area of social evolution. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Amy Morris-Drake
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Patrick Kennedy
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Ines Braga Goncalves
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Andrew N Radford
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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23
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Lemoine SRT, Samuni L, Crockford C, Wittig RM. Parochial cooperation in wild chimpanzees: a model to explain the evolution of parochial altruism. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210149. [PMID: 35369746 PMCID: PMC8977654 DOI: 10.1098/rstb.2021.0149] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/24/2022] [Indexed: 12/18/2022] Open
Abstract
Parochial altruism, taking individual costs to benefit the in-group and harm the out-group, has been proposed as one of the mechanisms underlying the human ability of large-scale cooperation. How parochial altruism has evolved remains unclear. In this review paper, we formulate a parochial cooperation model in small-scale groups and examine the model in wild chimpanzees. As suggested for human parochial altruism, we review evidence that the oxytocinergic system and in-group cooperation and cohesion during out-group threat are integral parts of chimpanzee collective action during intergroup competition. We expand this model by suggesting that chimpanzee parochial cooperation is supported by the social structure of chimpanzee groups which enables repeated interaction history and established social ties between co-operators. We discuss in detail the role of the oxytocinergic system in supporting parochial cooperation, a pathway that appears integral already in chimpanzees. The reviewed evidence suggests that prerequisites of human parochial altruism were probably present in the last common ancestor between Pan and Homo. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Sylvain R. T. Lemoine
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Archaeology, University of Cambridge, Cambridge, UK
| | - Liran Samuni
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Catherine Crockford
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institute of Cognitive Sciences Marc Jeannerod, UMR 5229, CNRS/University of Lyon, Bron, France
| | - Roman M. Wittig
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institute of Cognitive Sciences Marc Jeannerod, UMR 5229, CNRS/University of Lyon, Bron, France
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24
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Bouchard A, Zuberbühler K. Male chimpanzees communicate to mediate competition and cooperation during feeding. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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25
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Love thy neighbour: behavioural and endocrine correlates of male strategies during intergroup encounters in bonobos. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.02.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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26
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An intentional cohesion call in male chimpanzees of Budongo Forest. Anim Cogn 2022; 25:853-866. [PMID: 35044524 PMCID: PMC9334450 DOI: 10.1007/s10071-022-01597-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 01/03/2022] [Accepted: 01/06/2022] [Indexed: 11/18/2022]
Abstract
Many social animals travel in cohesive groups but some species, including chimpanzees, form flexible fission–fusion systems where individuals have some control over group cohesion and proximity to others. Here, we explored how male chimpanzees of the Sonso community of Budongo Forest, Uganda, use communication signals during resting, a context where the likelihood of group fission is high due to forthcoming travel. We focused on a context-specific vocalisation, the ‘rest hoo’, to investigate its function and determine whether it is produced intentionally. We found that this call was typically given towards the end of typical silent resting bouts, i.e., the period when individuals need to decide whether to continue travelling after a brief stop-over or to start a prolonged resting bout. Subjects rested longer after producing ‘rest hoos’ and their resting time increased with the number of calls produced. They also rested longer if their calls were answered. Furthermore, focal subjects’ resting time was prolonged after hearing others’ ‘rest hoos’. Subjects called more when with top proximity partners and in small parties and rested longer if a top proximity partner called. We also found an interaction effect between rank and grooming activity, with high-ranking males with a high grooming index calling less frequently than other males, suggesting that vocal communication may serve as a cohesion strategy alternative to tactile-based bonding. We discuss these different patterns and conclude that chimpanzee ‘rest hoos’ meet key criteria for intentional signalling. We suggest that ‘rest hoos’ are produced to prolong resting bouts with desired partners, which may function to increase social cohesion.
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Wikberg EC, Gonzalez S, Rodriguez C, Sicotte P. Joint intergroup aggression in female colobus monkeys (Colobus vellerosus) is associated with grooming bonds, male participation, and group size. Am J Primatol 2021; 84:e23355. [PMID: 34927751 DOI: 10.1002/ajp.23355] [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: 04/08/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 11/06/2022]
Abstract
Cooperative home range defense is common in primates, despite a collective action problem that arises when group members benefit from winning the intergroup encounter regardless of whether they participate. The costs associated with this collective action problem may be mitigated by residing in small groups, residing with kin, or by forming strong bonds with group members. The potential to decouple the effects of these variables provided an opportunity to investigate which of these three variables best explains coparticipation in intergroup encounters among adult and subadult female colobus at Boabeng-Fiema, Ghana. Because males are often the main participants, we also investigated the relationship between female-female coparticipation and adult and subadult male participation. We collected intergroup behaviors from 94 adult and subadult individuals in eight groups during 1 year. We quantified female grooming bond strength and approach rates using focal samples. We classified female dyads as close kin (i.e., halfsiblings or more closely related) or nonkin based on partial pedigrees and genotypes generated from 17 STR loci. Female-female coparticipation was higher in dyads with stronger grooming bonds but was not associated with dyadic kinship, approach rate, or age class. Female coparticipation decreased with increasing female group size as expected if there is a collective action problem. Females coparticipated less in groups with more males and male intergroup aggression, possibly because there is less need for female-female cooperation if males are participating in the intergroup encounter. Females in smaller groups may not only benefit from increased female-female cooperation during intergroup encounters, they are also likely to reside with a higher-quality alpha male, both of which may increase the likelihood of winning intergroup encounters. There may be strong selection for facultative female dispersal in populations like the Boabeng-Fiema colobus in which small groups are associated with multiple benefits and cooperation is not affected by kinship.
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Affiliation(s)
- Eva C Wikberg
- Department of Anthropology, University of Texas at San Antonio, Texas, USA
| | - Sofia Gonzalez
- Department of Anthropology, University of Texas at San Antonio, Texas, USA
| | - Cynthia Rodriguez
- Department of Anthropology, University of Texas at San Antonio, Texas, USA
| | - Pascale Sicotte
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada.,Department of Biology, Concordia University, Montréal, Quebec, Canada
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Attractiveness of female sexual signaling predicts differences in female grouping patterns between bonobos and chimpanzees. Commun Biol 2021; 4:1119. [PMID: 34556787 PMCID: PMC8460808 DOI: 10.1038/s42003-021-02641-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/06/2021] [Indexed: 12/27/2022] Open
Abstract
Here we show that sexual signaling affects patterns of female spatial association differently in chimpanzees and bonobos, indicating its relevance in shaping the respective social systems. Generally, spatial association between females often mirrors patterns and strength of social relationships and cooperation within groups. While testing for proposed differences in female-female associations underlying female coalition formation in the species of the genus Pan, we find only limited evidence for a higher female-female gregariousness in bonobos. While bonobo females exhibited a slightly higher average number of females in their parties, there is neither a species difference in the time females spent alone, nor in the number of female party members in the absence of sexually attractive females. We find that the more frequent presence of maximally tumescent females in bonobos is associated with a significantly stronger increase in the number of female party members, independent of variation in a behavioural proxy for food abundance. This indicates the need to look beyond ecology when explaining species differences in female sociality as it refutes the idea that the higher gregariousness among bonobo females is driven by ecological factors alone and highlights that the temporal distribution of female sexual receptivity is an important factor to consider when studying mammalian sociality. Surbeck and colleagues investigate the proximate drivers of female gregariousness in bonobos and chimpanzees across different observed communities. Their findings indicate that varied levels of sexual signalling in these two species result in different social behaviours regarding female grouping and potentially cooperation.
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29
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Thompson González N, Machanda Z, Otali E, Muller MN, Enigk DK, Wrangham R, Emery Thompson M. Age-related change in adult chimpanzee social network integration. Evol Med Public Health 2021; 9:448-459. [PMID: 34987824 PMCID: PMC8697844 DOI: 10.1093/emph/eoab040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 11/18/2021] [Indexed: 12/04/2022] Open
Abstract
Background Social isolation is a key risk factor for the onset and progression of age-related disease and mortality in humans. Nevertheless, older people commonly have narrowing social networks, with influences from both cultural factors and the constraints of senescence. We evaluate evolutionarily grounded models by studying social aging in wild chimpanzees, a system where such influences are more easily separated than in humans, and where individuals are long-lived and decline physically with age. Methodology We applied social network analysis to examine age-related changes in social integration in a 7+ year mixed-longitudinal dataset on 38 wild adult chimpanzees (22 females, 16 males). Metrics of social integration included social attractivity and overt effort (directed degree and strength), social roles (betweenness and local transitivity) and embeddedness (eigenvector centrality) in grooming networks. Results Both sexes reduced the strength of direct ties with age (males in-strength, females out-strength). However, males increased embeddedness with age, alongside cliquishness. These changes were independent of age-related changes in social and reproductive status. Both sexes maintained highly repeatable inter-individual differences in integration, particularly in mixed-sex networks. Conclusions and implications As in humans, chimpanzees appear to experience senescence-related declines in social engagement. However, male social embeddedness and overall sex differences were patterned more similarly to humans in non-industrialized versus industrialized societies. Such comparisons suggest common evolutionary roots to ape social aging and that social isolation in older humans may hinge on novel cultural factors of many industrialized societies. Lastly, individual and sex differences are potentially important mediators of successful social aging in chimpanzees, as in humans. Lay summary: Few biological models explain why humans so commonly have narrowing social networks with age, despite the risk factor of social isolation that small networks pose. We use wild chimpanzees as a comparative system to evaluate models grounded in an evolutionary perspective, using social network analysis to examine changes in integration with age. Like humans in industrialized populations, chimpanzees had lower direct engagement with social partners as they aged. However, sex differences in integration and older males’ central positions within the community network were more like patterns of sociality in several non-industrialized human populations. Our results suggest common evolutionary roots to human and chimpanzee social aging, and that the risk of social isolation with age in industrialized populations stems from novel cultural factors.
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Affiliation(s)
- Nicole Thompson González
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
- Health Sciences Center, University of New Mexico, Academic Science Education and Research Training program, Albuquerque, NM 87131, USA
| | - Zarin Machanda
- Kibale Chimpanzee Project, Fort Portal, Uganda
- Department of Anthropology, Tufts University, Medford, MA 02155, USA
| | - Emily Otali
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Martin N Muller
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Drew K Enigk
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Richard Wrangham
- Kibale Chimpanzee Project, Fort Portal, Uganda
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Melissa Emery Thompson
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
- Kibale Chimpanzee Project, Fort Portal, Uganda
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