The impact of gossip, reputation, and context on resource transfers among Aka hunter-gatherers, Ngandu horticulturalists, and MTurkers. Nicole H. Hess, Edward H. Hagen. Evolution and Human Behavior, March 11 2023. https://doi.org/10.1016/j.evolhumbehav.2023.02.013
Abstract: Theoretical models of gossip's role in the evolution of cooperation in ancestral human communities, and its role in within-group competition for resources, require gossip to cause changes in individuals' reputations, which then cause changes in the likelihood of their receiving benefits. However, there is scant experimental evidence from small-scale societies supporting such causal relationships. There is also little experimental evidence that, when making decisions about the transfer of resources, gossip receivers weigh gossip according to its relevance to the social context in which such transfers occur. Using an experimental vignette study design, in a sample from MTurk (N = 120) and another sample from a remote horticultural population, the Ngandu of the Central African Republic (CAR) (N = 160), we test whether positive and negative gossip increase and decrease the likelihood of transferring resources, respectively, mediated by their effects on reputation. We also test whether gossip that is relevant to the context of the resource transfer has a larger impact on reputation than other gossip. We found strong significant, context-relevant effects of gossip on participant willingness to transfer benefits, mediated by gossip's effects on reputation. Then, in an exploratory observational study of Aka hunter-gatherers of CAR using peer-reports (N = 40), we investigate whether providing benefits to the group (such as working hard, parenting or alloparenting, or sharing) and genetic relatedness to the group, were associated with reputations and receiving benefits. We found that, although having a good reputation was associated with receiving more benefits, there was a stark sex difference, with almost all women scoring higher than almost all men on a dimension involving better parenting, good reputations, and receipt of more benefits.
Introduction
Humans evolved in groups that cooperated to obtain food, defend themselves from predators and other humans, and care for children, the injured, and the sick (Martin, Ringen, Duda, & Jaeggi, 2020; Ringen, Duda, & Jaeggi, 2019; Sugiyama, 2004). Some benefits, such as defense from predators and enemies, were non-excludable public goods – all group members would necessarily obtain the benefit. Other benefits, though, such as food and care, were potentially excludable – they could be distributed unequally to group members. Successful hunters could provide more meat to their wives and children, for instance, although the extent to which this happens in contemporary foraging societies is fiercely debated (Blurton Jones, 1987; Hawkes, O'Connell, & Blurton Jones, 2014; Jaeggi & Gurven, 2013; Ringen et al., 2019; Stibbard-Hawkes, 2019; Stibbard-Hawkes, Attenborough, Mabulla, & Marlowe, 2020; Wood & Marlowe, 2013). As another example, Rucas, Gurven, Kaplan, and Winking (2010) found that Tsimane women excluded resources from women with whom they had disputes or conflicts compared to favored female neighbors or desired friends. Studies in high income countries find that individuals perceived as lazy are seen as less deserving of resource transfers, such as welfare payments, than are victims of misfortune, and these perceptions influence social policies (Jensen & Petersen, 2017; Petersen, 2012).
Inclusive fitness is a compelling explanation for the provisioning of excludable benefits within families, such as food, alloparenting, and care of the sick and injured. Indeed, intergenerational transfers of material, embodied, and relational wealth within families establish and maintain inequality in a wide range of small-scale societies (Mulder et al., 2009). Yet levels of inequality in foraging and horticultural societies, specifically, are relatively low (Mulder et al., 2009). This is despite the fact that relatedness within such communities, which comprise a fluid mix of genetic kin, affines, and unrelated adults, is generally low (Dyble et al., 2015; Hill et al., 2011).
A diverse group of theories has been proposed to explain the willingness to provide resources to unrelated community members, including reciprocal altruism (Allen-Arave, Gurven, & Hill, 2008; Jaeggi & Gurven, 2013), investing in those who provide valuable group benefits (Gurven, Allen-Arave, Hill, & Hurtado, 2000; Sugiyama, 2004; Sugiyama & Chacon, 2000; Sugiyama & Sugiyama, 2003), providing resources to others as a costly signal of quality (the ‘show-off’ models) (Bliege Bird & Smith, 2005; Gintis, Smith, & Bowles, 2001; Hawkes & Bliege Bird, 2002; Stibbard-Hawkes, 2019), risk-buffering and fitness interdependence (Aktipis et al., 2018; Smith et al., 2019), and indirect reciprocity (Alexander, 1986; Balliet, Wu, & van Lange, 2020; Leimar & Hammerstein, 2001; Nowak & Sigmund, 2005).
In several of these theories, in order to receive benefits from others, individuals must have a “good” reputation. Reputation is based on information about one's traits, behaviors, intentions, abilities, and culturally-relevant competencies. A study of 153 cultures in the ethnographic record investigated the evidence for 20 domains of reputation identified in the theoretical literature. Domains that were widely supported across cultures included cultural conformity (conforming to cultural norms or excelling in culturally-valued skills), being knowledgeable, intelligent, prosocial, and industrious, and having social status. These domains formed clusters, with the most cross-cultural evidence for cultural group unity (e.g., cultural conformity, prosociality, and industriousness), social and material success (social and material capital and status), and neural capital (knowledgeable, oratory skill) (Garfield et al., 2021).
Information on the degree to which individuals in one's community excel or fall short on each of these reputational domains or contexts can be obtained via direct observation, or from other individuals in the community, i.e., gossip. Several theories have been put forward for the evolution of gossip, including ‘cultural learning’; ‘social learning,’ such as learning norms or one's place in a group or acquiring new and important knowledge; strategy learning; social comparison; a mechanism for showing off one's social skill and connections, and therefore one's mate value; norm learning and enforcement; sanctioning, social control, or ‘policing’; a means to maintain the good reputations of allies; and as a means to maintain the unity, morals, and values of social groups (reviewed in Hess & Hagen, 2019). One early attempt to explain the relationship between gossip and cooperation comes from Dunbar (1996), who suggested that because grooming would be too time-consuming in the large groups that are typical of humans, gossip replaced it as a means to create and maintain social bonds. However, a recent study found no support for the ‘vocal grooming’ hypothesis as a less time-consuming means of bonding (Jaeggi et al., 2017).
The key role of gossip and reputation in the evolution of human cooperation, especially via indirect reciprocity, is starting to receive considerable attention (Balliet et al., 2020; Wu, Balliet, & Van Lange, 2016b). Gossip has been demonstrated to increase cooperation via indirect reciprocity in experimental economics games (e.g., Sommerfeld, Krambeck, Semmann, & Milinski, 2007) where reputational information impacts contributions to a shared pool of resources (e.g., Beersma & Van Kleef, 2011), or where information about the past behaviors of cooperative partners impacts participants' inclinations to engage in future cooperation (e.g., Feinberg, Willer, & Schultz, 2014). Cooperators in public goods games, in turn, transmit more honest gossip (Giardini, Vilone, Sánchez, & Antonioni, 2021). Gossip was found to be more effective and efficient than punishment in promoting and maintaining cooperation in a public goods game (Wu, Balliet, & Van Lange, 2016a), and gossip also increases cooperation in the dictator and ultimatum games (Wu, Balliet, Kou, & Van Lange, 2019). However, a confederate's negative gossip about a third party did not enhance participant cooperation in a prisoner's dilemma game (De Backer, Larson, Fisher, McAndrew, & Rudnicki, 2016). In addition, agent-based simulations have explored how varying the quantity and quality of gossip impacts cooperation (Giardini, Paolucci, Villatoro, & Conte, 2014; Giardini & Vilone, 2016).
When reputation mediates access to group resources, competition for those resources by group members will often take the form of gossip that aims to increase one's reputation relative to that of competitors. A considerable body of evidence from industrialized populations demonstrates that gossiping is a key strategy in indirect aggression, the suite of behaviors that are used to harm others but that do not involve hitting or other types of physical force (for reviews, see Archer & Coyne, 2005; Hess & Hagen, 2019). Ethnographic studies of gossip find that it is often used in reputation management, i.e., maintaining and improving one's reputation relative to others (Hess, 2017). In a study among Aka, for example, a Congo Basin hunter-gatherer population, peer-rated gossiping was strongly positively correlated with peer-rated anger for both women and men, confirming that Aka perceive gossip as aggressive (Hess, Helfrecht, Hagen, Sell, & Hewlett, 2010). Several studies with US, multinational online, and non-Western samples have also found that gossip is used to either obtain or defend social resources, such as friends and mates (Fisher & Cox, 2011; Krems, Williams, Aktipis, & Kenrick, 2020; Rucas, 2017; Rucas et al., 2006; Stone, 2015; Sutton, 2014; Sutton & Oaten, 2017). Regarding material resources, an experimental vignette study with an MTurk sample found competition for a limited material resource increased gossip, especially negative gossip (Hess & Hagen, 2021), and among North American women a resource scarcity prime increased rival derogation (Arnocky, Davis, & Vaillancourt, 2022).
Campbell (1999) proposed that because the costs of physical aggression are higher for women, female aggression is more likely to take the form of indirect aggression, such as negative gossip. Influenced by Campbell, many evolutionary studies of gossip and competition have therefore focused on women (for reviews, see Fisher, 2017; McAndrew, 2017; Reynolds, 2022). However, the link between indirect aggression and female competition specifically is complicated by the finding that there are few sex differences in indirect aggression (Archer & Coyne, 2005).
Alternatively, Hess and Hagen (2019) proposed that in competition over resources within interdependent groups, negative gossip is more effective than physical aggression for both sexes because one can reduce resource transfers to a competitor by harming his or her reputation, thereby increasing resource availability for oneself, without impairing the competitor's physical ability to continue contributing to the group. Positive gossip by either sex could increase transfers to a relative, or ally by improving his or her reputation. This perspective does not predict sex differences in within-group competitive gossip.
Because individuals' reputations can differ in different social contexts (Garfield et al., 2021), reputation-based decisions to gossip about others, or to provide benefits, should be sensitive to the context in which competition or help is occurring. To influence resource transfers within families, for instance, one should relay gossip that is relevant to family members, and to influence resource transfers within communities, one should relay gossip that is relevant to community members. In an experimental study involving competition over limited resources in a family vs. work context, Hess and Hagen (2021) found, as predicted, that individuals transmitted more family gossip in a family context and more work gossip in a work context.
The theoretical models of the role of gossip in the evolution of cooperation in ancestral human communities require gossip to cause changes in individuals' reputations,which then cause changes in the likelihood of providing benefits to them. However, there is scant evidence from small-scale societies of such causal relationships. There is also no evidence that, when making a decision about the transfer of resources, gossip receivers weigh gossip according to its relevance to the social context.
Posts
