Henry F. Lyle

The reputational and social network benefits of prosociality in an Andean community

Significance Scientists have long debated how group cooperation can be maintained. From many standard evolutionary and economic perspectives, the best decision for an individual is to engage in free riding on the cooperation of others (i.e., share in the benefits but pay no costs). Such free riding, however, reduces the collective benefits of group cooperation and can unravel cooperation. Some propose that this “tragedy of the commons” can be solved if cooperators are compensated with reputational benefits. Our research in an Andean community found that cooperative households have better reputations for various qualities and have larger support networks, with the latter associated with healthier households. This finding supports the argument that positive reputations gained by cooperators can solve the tragedy of the commons. Several theories have emerged to explain how group cooperation (collective action) can arise and be maintained in the face of incentives to engage in free riding. Explanations focusing on reputational benefits and partner choice have particular promise for cases in which punishment is absent or insufficient to deter free riding. In indigenous communities of highland Peru, collective action is pervasive and provides critical benefits. Participation in collective action is unequal across households, but all households share its benefits. Importantly, investment in collective action involves considerable time, energy, and risk. Differential participation in collective action can convey information about qualities of fellow community members that are not easily observable otherwise, such as cooperative intent, knowledge, work ethic, skill, and/or physical vitality. Conveying such information may enhance access to adaptive support networks. Interview and observational data collected in a Peruvian highland community indicate that persons who contributed more to collective action had greater reputations as reliable, hard workers with regard to collective action and also were considered the most respected, influential, and generous people in the community. Additionally, household heads with greater reputations had more social support partners (measured as network indegree centrality), and households with larger support networks experienced fewer illness symptoms.

Blood donations as costly signals of donor quality

This is the first empirical investigation of blood donations in evolutionary perspective. We examine blood donor and non-donor attitudes about health and injury risks, donor characteris- tics, and the social value of donor participation. We propose that blood donations may communi- cate qualities about donors to third parties. Observers may benefit from information about the do- nors health, value as a reciprocal partner, and/or ability to endure what is perceived as an anxi- ety-provoking and risky experience. Donors may benefit from an enhanced reputation, which can lead to greater access to cooperative networks and high-quality partners. We found that partici- pants recognized the need for blood and perceived blood donors as generous and healthy. Study results indicated that anxiety and the perceived risk of a negative health consequence dramatically affected the willingness of donors and non-donors to donate blood in the future. These findings support our hypothesis that the act of blood donation may signal adaptive information about do- nor quality to third parties.

Multiple reputation domains and cooperative behaviour in two Latin American communities

Reputations are a ubiquitous feature of human social life, and a large literature has been dedicated to explaining the relationship between prosocial reputations and cooperation in social dilemmas. However, humans form reputations in domains other than prosociality, such as economic competency that could affect cooperation. To date, no research has evaluated the relative effects of multiple reputation domains on cooperation. To bridge this gap, we analyse how prosocial and competency reputations affect cooperation in two Latin American communities (Bwa Mawego, Dominica, and Pucucanchita, Peru) across a number of social contexts (Dominica: labour contracting, labour exchange and conjugal partnership formation; Peru: agricultural and health advice network size). First, we examine the behavioural correlates of prosocial and competency reputations. Following, we analyse whether prosocial, competency, or both reputation domains explain the flow of cooperative benefits within the two communities. Our analyses suggest that (i) although some behaviours affect both reputation domains simultaneously, each reputation domain has a unique behavioural signature; and (ii) competency reputations affect cooperation across a greater number of social contexts compared to prosocial reputations. Results are contextualized with reference to the social markets in which behaviour is embedded and a call for greater theory development is stressed.

How Conservative Are Evolutionary Anthropologists

The application of evolutionary theory to human behavior has elicited a variety of critiques, some of which charge that this approach expresses or encourages conservative or reactionary political agendas. In a survey of graduate students in psychology, Tybur, Miller, and Gangestad (Human Nature, 18, 313–328, 2007) found that the political attitudes of those who use an evolutionary approach did not differ from those of other psychology grad students. Here, we present results from a directed online survey of a broad sample of graduate students in anthropology that assays political views. We found that evolutionary anthropology graduate students were very liberal in their political beliefs, overwhelmingly voted for a liberal U.S. presidential candidate in the 2008 election, and identified with liberal political parties; in this, they were almost indistinguishable from non-evolutionary anthropology students. Our results contradict the view that evolutionary anthropologists hold conservative or reactionary political views. We discuss some possible reasons for the persistence of this view in terms of the sociology of science.

Competitive Status Signaling in Peer-to-Peer File-Sharing Networks

Internet peer-to-peer file sharing is a contemporary example of asymmetrical sharing in which “altruists” (file uploaders) share unconditionally with non-reciprocating “free riders” (file downloaders). Those who upload digital media files over the Internet risk prosecution for copyright infringement, and are more vulnerable to computer hackers and viruses. In an analysis of file-sharing behavior among university undergraduates (N=331), we found that significantly more males than females engaged in risky file uploading. Contrary to expectations, uploaders were not concerned about their reputation online and file sharers were not interested in identifying or chatting with uploaders while online. Among uploaders, males were more likely than females to be identified as uploaders by friends, to discuss uploading and to upload in the presence of peers. We interpret these results using costly-signaling theory, and argue that uploading is a costly signal in which males engage in avoidable risk taking as a means to compete for status among peers in social contexts other than the Internet.

Cognitive Adaptation and Collective Action: The P2P File-Sharing Phenomenon

Collective action is a universal characteristic of modern human populations and was likely an adaptive characteristic of our Pleistocene ancestors. Consequently, it has been proposed that selective pressures associated with cooperation favored cognitive adaptations. These adaptations may or may not respond adaptively in novel environments of collective action, such as those created by recent technological innovations. The Internet P2P file-sharing phenomenon is an extraordinary example of collective action that occurs in novel online social environments . In P2P file-sharing networks , altruistic uploaders provide a collective good (i.e., digital media) despite the presence of a large number of non-reciprocating file downloaders. In doing so, uploaders risk prosecution for copyright infringement and are more vulnerable to computer hackers and viruses compared with those who strictly download. In this chapter, we consider the hypothesis that uploading is a costly signal in which males engage in avoidable risk taking as a means to compete for status among their peers on the Internet as well as those they interact with in their everyday social lives.