In their target article, McCullough et al. propose that cognitive systems for revenge and forgiveness result from psychological adaptations that helped solve certain social problems encountered through the course of human evolution. While the authors develop an important new perspective on the evolutionary origins of such behaviors, they make several assumptions that, we believe, limit the scope and applicability of their own thesis. Most notably, they “take no position on whether the psychology that governs the operation of revenge systems (…) also evolve to regulate behavior in intergroup contexts” (sect. 2.2.4, para. 2). In what follows we argue that the authors' model should be extended to include intergroup contexts, and that it correspondingly has potentially important implications for understanding the nature of conflict and cooperation between groups.
Research into the origins of group behavior has established the key role that intergroup relations have played in the evolution of social cognition. This work suggests that “the group” constitutes the “mind's natural environment,” acting as the interface between an individual and their physical environment (Caporael Reference Caporael1997). As such fitness should be correlated with the development of functionalized cognitive mechanisms supporting the development of relationships that necessarily include intergroup comparisons (Caporael & Baron Reference Caporael, Baron, Simpson and Kenrick1997). Being able to effectively make such comparisons is critical, because in ancestral environments clear cognitive representations of ingroup (us) versus outgroup (them) boundaries affords significant functional benefits such as maximizing security and limiting the potential for disease transmission.
If we accept that intergroup cognition has an evolutionary origin, could the same basic system be used in intragroup contexts (and vice versa)? McCullough et al. suggest not, and that a different cognitive architecture may have evolved to govern intergroup conflict compared to intragroup conflict (sect. 2.2.4, para. 2). Our contention is that, in evolutionary terms, systems for regulating intra- and intergroup behavior should be intimately linked because they involve precisely the same computational requirements. In other words, determining whether to retaliate to a member of one's coalition, and subsequent reconciliatory behavior, can apply just as much (and perhaps more crucially) when negotiating competitive and cooperative intergroup relations.
Evidence for this “converging systems hypothesis” can be found in research on intergroup relations that has demonstrated the operation of precisely the same mechanisms as revealed in studies of intragroup public goods dilemmas (including some of the same studies cited by the authors; e.g., Fehr & Gächter Reference Fehr and Gächter2002; Kollock Reference Kollock1998; Ostrom Reference Ostrom1990; Yamagishi Reference Yamagishi1986). Specifically, converging systems are evident when it comes to general incentives for cooperation and non-cooperation that apply to larger social contexts in which groups compete for resources (i.e., intergroup contexts). Take Sherif's (Reference Sherif1966) classic realistic group conflict theory. This intergroup theory is based on the assumption, shared by much work on intragroup public dilemmas, that conflicts are “rational” in the sense that opposing groups have incompatible goals and compete for scarce resources (Taylor & Moghaddam Reference Taylor and Moghaddam1987). Bornstein (Reference Bornstein2003) similarly argues that intragroup dilemmas are embedded within, and indeed characterize, intergroup conflict and cooperation. He notes that before it is rational for groups to compete, it must be rational for the individual group members to do so. In other words, the benefits associated with the outcome of intergroup conflict (e.g., security, territory, political power, status, pride) are public goods which extend to all group members regardless of their individual contribution. As Dawes (Reference Dawes1980) states, “Soldiers who fight in a large battle can reasonably conclude that no matter what their comrades do they personally are better off taking no chances; yet if no one takes chances, the result will be a rout and slaughter worse for all the soldiers” (p. 170). In sum, the types of social dilemmas cited by the authors are inherently embedded within, and indeed characterize, situations of intergroup conflict and cooperation. This suggests that common processes can determine both intra- and intergroup outcomes, and provides a basis for predicting a similar level of convergence when it comes to the computational systems involved.
The potential relevance of this convergence becomes apparent when considering the central role revenge and forgiveness have played in contemporary theories of intergroup conflict and its reduction. In fact, when McCullough et al. conclude that “the attention placed on revenge and forgiveness in the psychological literature has been somewhat limited and undertheorized” (sect. 7, para. 2), we would point out that revenge and forgiveness have been key concepts in over 60 years of research on the potential for intergroup contact to reduce conflict (Allport Reference Allport1954; Brown & Hewstone Reference Brown, Hewstone and Zanna2005; Pettigrew & Tropp Reference Pettigrew and Tropp2006). Mechanisms underlying processes of forgiveness and reconciliation are particularly central to this work, and relevant cognitions and emotions such as perspective-taking and empathy are well-specified (Hewstone et al. Reference Hewstone, Cairns, Voci, Hamberger and Niens2006; Paolini et al. Reference Paolini, Hewstone, Cairns and Voci2004; Turner et al. Reference Turner, Hewstone, Voci and Vonofakou2008). Furthermore, anthropological and sociological studies have shown that contact outcomes, such as the formation of relationships that cut across tribal boundaries, promote forgiveness and reconciliation (Coser Reference Coser1956; Deutsch Reference Deutsch1973; Evans-Pritchard Reference Evans-Pritchard1940; LeVine & Campbell Reference LeVine and Campbell1972). This work suggests that groups have an evolved propensity to engage in intergroup contact precisely because it can give rise to cross-cutting affiliations that ensure stability and security (i.e., it is more difficult to have conflictual relations with a group based on territory that is simultaneously an ally according to common ancestry; Crisp & Hewstone Reference Crisp, Hewstone and Zanna2007). Notably, recent work has begun to specify the computational mechanisms through which these positive intergroup relations can be established (Crisp & Turner Reference Crisp and Turner2009; Reference Crisp and Turner2011). Considering how these contributory cognitive systems evolved will help us develop a clearer understanding of how and when contact can be successful in tackling contemporary intergroup conflicts. It may also help us move closer to understanding how these computational systems enabled ancestral coalition building, and through this, the construction of complex societies.
In their target article, McCullough et al. propose that cognitive systems for revenge and forgiveness result from psychological adaptations that helped solve certain social problems encountered through the course of human evolution. While the authors develop an important new perspective on the evolutionary origins of such behaviors, they make several assumptions that, we believe, limit the scope and applicability of their own thesis. Most notably, they “take no position on whether the psychology that governs the operation of revenge systems (…) also evolve to regulate behavior in intergroup contexts” (sect. 2.2.4, para. 2). In what follows we argue that the authors' model should be extended to include intergroup contexts, and that it correspondingly has potentially important implications for understanding the nature of conflict and cooperation between groups.
Research into the origins of group behavior has established the key role that intergroup relations have played in the evolution of social cognition. This work suggests that “the group” constitutes the “mind's natural environment,” acting as the interface between an individual and their physical environment (Caporael Reference Caporael1997). As such fitness should be correlated with the development of functionalized cognitive mechanisms supporting the development of relationships that necessarily include intergroup comparisons (Caporael & Baron Reference Caporael, Baron, Simpson and Kenrick1997). Being able to effectively make such comparisons is critical, because in ancestral environments clear cognitive representations of ingroup (us) versus outgroup (them) boundaries affords significant functional benefits such as maximizing security and limiting the potential for disease transmission.
If we accept that intergroup cognition has an evolutionary origin, could the same basic system be used in intragroup contexts (and vice versa)? McCullough et al. suggest not, and that a different cognitive architecture may have evolved to govern intergroup conflict compared to intragroup conflict (sect. 2.2.4, para. 2). Our contention is that, in evolutionary terms, systems for regulating intra- and intergroup behavior should be intimately linked because they involve precisely the same computational requirements. In other words, determining whether to retaliate to a member of one's coalition, and subsequent reconciliatory behavior, can apply just as much (and perhaps more crucially) when negotiating competitive and cooperative intergroup relations.
Evidence for this “converging systems hypothesis” can be found in research on intergroup relations that has demonstrated the operation of precisely the same mechanisms as revealed in studies of intragroup public goods dilemmas (including some of the same studies cited by the authors; e.g., Fehr & Gächter Reference Fehr and Gächter2002; Kollock Reference Kollock1998; Ostrom Reference Ostrom1990; Yamagishi Reference Yamagishi1986). Specifically, converging systems are evident when it comes to general incentives for cooperation and non-cooperation that apply to larger social contexts in which groups compete for resources (i.e., intergroup contexts). Take Sherif's (Reference Sherif1966) classic realistic group conflict theory. This intergroup theory is based on the assumption, shared by much work on intragroup public dilemmas, that conflicts are “rational” in the sense that opposing groups have incompatible goals and compete for scarce resources (Taylor & Moghaddam Reference Taylor and Moghaddam1987). Bornstein (Reference Bornstein2003) similarly argues that intragroup dilemmas are embedded within, and indeed characterize, intergroup conflict and cooperation. He notes that before it is rational for groups to compete, it must be rational for the individual group members to do so. In other words, the benefits associated with the outcome of intergroup conflict (e.g., security, territory, political power, status, pride) are public goods which extend to all group members regardless of their individual contribution. As Dawes (Reference Dawes1980) states, “Soldiers who fight in a large battle can reasonably conclude that no matter what their comrades do they personally are better off taking no chances; yet if no one takes chances, the result will be a rout and slaughter worse for all the soldiers” (p. 170). In sum, the types of social dilemmas cited by the authors are inherently embedded within, and indeed characterize, situations of intergroup conflict and cooperation. This suggests that common processes can determine both intra- and intergroup outcomes, and provides a basis for predicting a similar level of convergence when it comes to the computational systems involved.
The potential relevance of this convergence becomes apparent when considering the central role revenge and forgiveness have played in contemporary theories of intergroup conflict and its reduction. In fact, when McCullough et al. conclude that “the attention placed on revenge and forgiveness in the psychological literature has been somewhat limited and undertheorized” (sect. 7, para. 2), we would point out that revenge and forgiveness have been key concepts in over 60 years of research on the potential for intergroup contact to reduce conflict (Allport Reference Allport1954; Brown & Hewstone Reference Brown, Hewstone and Zanna2005; Pettigrew & Tropp Reference Pettigrew and Tropp2006). Mechanisms underlying processes of forgiveness and reconciliation are particularly central to this work, and relevant cognitions and emotions such as perspective-taking and empathy are well-specified (Hewstone et al. Reference Hewstone, Cairns, Voci, Hamberger and Niens2006; Paolini et al. Reference Paolini, Hewstone, Cairns and Voci2004; Turner et al. Reference Turner, Hewstone, Voci and Vonofakou2008). Furthermore, anthropological and sociological studies have shown that contact outcomes, such as the formation of relationships that cut across tribal boundaries, promote forgiveness and reconciliation (Coser Reference Coser1956; Deutsch Reference Deutsch1973; Evans-Pritchard Reference Evans-Pritchard1940; LeVine & Campbell Reference LeVine and Campbell1972). This work suggests that groups have an evolved propensity to engage in intergroup contact precisely because it can give rise to cross-cutting affiliations that ensure stability and security (i.e., it is more difficult to have conflictual relations with a group based on territory that is simultaneously an ally according to common ancestry; Crisp & Hewstone Reference Crisp, Hewstone and Zanna2007). Notably, recent work has begun to specify the computational mechanisms through which these positive intergroup relations can be established (Crisp & Turner Reference Crisp and Turner2009; Reference Crisp and Turner2011). Considering how these contributory cognitive systems evolved will help us develop a clearer understanding of how and when contact can be successful in tackling contemporary intergroup conflicts. It may also help us move closer to understanding how these computational systems enabled ancestral coalition building, and through this, the construction of complex societies.