The Conditions Favoring Between-Community Raiding in Chimpanzees, Bonobos, and Human Foragers

Pandit, Sagar A.; Pradhan, Gauri R.; Balashov, Hennadii; Schaik, Carel P. van

doi:10.1007/s12110-015-9252-5

Cited by 23 publications

(14 citation statements)

References 56 publications

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“…The design overcomes the social irrelevance of minimal groups without the labin-the-field model's social specificity through our subtle implementation of social information and use of an abstract type of group divide -social distance, in a basic manifestation, locality of origin. Territory, particularly during times of environmental scarcity, constitutes a basis for inter-individual and inter-group contentious behavior, including homicide and war (Wilson 1978;Manson & Wrangham 1991;Ember & Ember 1992;Gat 2006Gat 2015Pandit et al 2016;Glowacki et. al.2017).…”

Section: Methodsmentioning

confidence: 99%

Social Distance and Parochial Altruism: An Experimental Study

Boulu-Reshef

Schulhofer-Wohl

2019

SSRN Journal

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Parochial altruism -individual sacrifice to benefit the in-group and harm an out-groupundermines inter-group cooperation and is implicated in a plethora of politically-significant behaviors. We report new experimental findings about the impact of variation in social distance within the in-group together with variation in social distance between the in-and out-groups on parochial altruism. Building from a minimal group paradigm set-up, we find that differential social distance has a systematic effect on individual choice in a setting of potential inter-group conflict. In particular, parochial altruism is stimulated when individuals' distance to both their in-and out-group is high. A long-standing finding about behavior in contexts of inter-group conflict is that low social distance facilitates collective action. Our results suggest that the effects of high social distance may create a potential additional pathway to group-based individual action. Research on inter-group conflict and collective action can be advanced by investigating such effects.

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Section: Methodsmentioning

confidence: 99%

Social Distance and Parochial Altruism: An Experimental Study

Boulu-Reshef

Schulhofer-Wohl

2019

SSRN Journal

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“…The merged group arises either after the majority of men in the defeated group or only some of their elite are killed [ 5 ]. We call the first kind genocidal “all-out war” and the second kind regular “all-out war” war (the term all-out being added to distinguish it from raiding warfare [ 9 ]), and include the number of enemies killed as an important free parameter into the model. Ethnography shows there are many cases of small-scale societies where a defeated society was merged into the victorious society, even if the process took some time [ 22 , 39 ].…”

Section: The Basic Assumptions Of the Modelmentioning

confidence: 99%

“…When our ancestors were all still nomadic foragers and thus lived in fission-fusion societies without fixed settlements, warfare was predominantly in the form of raids [ 4 , 6 ]. Raiding can be modeled using a behavioral-ecology approach [ 9 ] similar to the one used in nonhuman species at both the individual [ 10 ] and coalition levels [ 11 , 12 , 13 ], where coalitions are defined as simultaneous and coordinated attacks by two or more partners on a common target. These functional models assume that natural selection has favored the evolution of information-gathering and decision-making mechanisms by individuals that optimally serve their fitness interests [ 14 ].…”

Section: Introductionmentioning

confidence: 99%

“…These functional models assume that natural selection has favored the evolution of information-gathering and decision-making mechanisms by individuals that optimally serve their fitness interests [ 14 ]. This approach revealed fundamental functional similarities between the raids of human foragers and chimpanzees, and outlined the conditions likely to favor raiding [ 9 , 15 ] as well as more detailed predictions about who is targeted [ 16 ]. Its success supports the assumption that men pursue their individual fitness interests when raiding [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

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A model for warfare in stratified small-scale societies: The effect of within-group inequality

2017

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In order to predict the features of non-raiding human warfare in small-scale, socially stratified societies, we study a coalitionary model of war that assumes that individuals participate voluntarily because their decisions serve to maximize fitness. Individual males join the coalition if war results in a net economic and thus fitness benefit. Within the model, viable offensive war ensues if the attacking coalition of males can overpower the defending coalition. We assume that the two groups will eventually fuse after a victory, with ranks arranged according to the fighting abilities of all males and that the new group will adopt the winning group’s skew in fitness payoffs. We ask whether asymmetries in skew, group size and the amount of resources controlled by a group affect the likelihood of successful war. The model shows, other things being equal, that (i) egalitarian groups are more likely to defeat their more despotic enemies, even when these are stronger, (ii) defection to enemy groups will be rare, unless the attacked group is far more despotic than the attacking one, and (iii) genocidal war is likely under a variety of conditions, in particular when the group under attack is more egalitarian. This simple optimality model accords with several empirically observed correlations in human warfare. Its success underlines the important role of egalitarianism in warfare.

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“…Current theory borrows from dyadic animal contest theory, for example, Hawk‐Dove evolutionary game theory (Maynard Smith, 1982) and theory of warfare, for example, Lanchester's law of attrition (Lanchester, 1914). These theories often assume that groups act as single entities during conflicts, or that groups are formed of identical individuals (Adams & Mesterton‐Gibbons, 2003; Fearon, 1995; Johnson & Toft, 2014; Rusch & Gavrilets, 2016; Sherratt & Mesterton‐Gibbons, 2013), although some recent theoretical work recognizes heterogeneity of groups (Bornstein, 2003; Gavrilets, 2015; Gavrilets & Fortunato, 2014; Pandit, Pradhan, Balashov, & Van Schaik, 2016). Empirical work highlights that individuals from the same group respond differently to intergroup conflicts—several studies have shown how different classes of individuals contribute to conflicts, including differences between males and females, differences across dominance rank, and differences between those with and without offspring in the group (Arseneau, Taucher, van Schaik, & Willems, 2015; Boydston, Morelli, & Holekamp, 2001; Kitchen & Beehner, 2007; Mares, Young, & Clutton‐Brock, 2012; Meunier, Molina‐Vila, & Perry, 2012; Muller & Mitani, 2002; Thompson et al, 2020; Van Belle, Garber, Estrada, & Di Fiore, 2014; Van Belle & Scarry, 2015).…”

Section: Introductionmentioning

confidence: 99%