Matthew Gervais: The University of California, Los Angeles

Experimental economic games have shed significant light on human population variation in social behavior. However, most of these games have involved anonymous dyadic recipients, limiting their external validity beyond fleeting pairwise interactions. Yet enduring relationships within large social networks are arguably the cradle of human uniqueness and remain the cornerstone of human adaptation across societies. Mapping the mechanisms that structure social behavior within human communities will require methods that have the virtues of economic games – including incentivized behavior, and replicability and comparability across populations – but which integrate multiple identifiable recipients and thereby tap Recipient Identity-Conditioned Heuristics (RICHs) such as direct and indirect reciprocity, trait- and state-based notions of fairness, and kinship norms. This talk describes three “relational” economic games that integrate recipient identities and other-other tradeoffs, and reports their validation in a study of male social relationships in a Fijian village. The three games, an Allocation Game, a Taking Game, and a Costly Reduction Game, involve monetary decisions made across a photo array of other villagers. Levels of both altruism and spite in these games are higher than those documented using dyadic anonymous games in neighboring villages. Recipient need is the major driver of giving and refraining from taking, while the wealthiest villagers are the mostly likely to be reduced at a cost, especially if they lack “Chiefly” character. Such need-based giving and leveling are hallmarks of human egalitarianism, and are well attested to in Fijian ethnography. Moreover, dyadic attitudes such as love, respect, hate, and fear partially mediate helping and punishing others, illuminating the psychological processes that regulate Fijian relationships. Relational economic games thus hold promise for mapping population variation in RICH norms and the mechanisms supporting cooperation within human communities, significantly advancing the toolkit of a scientific anthropology.