Kinship underlies costly cooperation in Mosuo villages

The relative importance of social evolution theories such as kin selection, direct reciprocity and need-based transfers in explaining real-world cooperation is the source of much debate. Previous field studies of cooperation in human communities have revealed variability in the extent to which each of these theories explains human sociality in different contexts. We conducted multivariate social network analyses predicting costly cooperation-labouring on another household's farm-in 128 082 dyads of Mosuo farming households in southwest China. Through information-theoretic model selection, we tested the roles played by genealogical relatedness, affinal relationships (including reproductive partners), reciprocity, relative need, wealth, household size, spatial proximity and gift-giving in an economic game. The best-fitting model included all factors, along with interactions between relatedness and (i) reciprocity, (ii) need, (iii) the presence of own children in another household and (iv) proximity. Our results show how a real-world form of cooperation was driven by kinship. Households tended to help kin in need (but not needy non-kin) and travel further to help spatially distant relatives. Households were more likely to establish reciprocal relationships with distant relatives and non-kin but closer kin cooperated regardless of reciprocity. These patterns of kin-driven cooperation show the importance of inclusive fitness in understanding human social behaviour

Gifts as Economic Signals and Social Symbols

Gift-giving has often puzzled economists, especially because efficient gifts-like cash or giving exactly what a person asks for-seem crass or inappropriate. It is shown in a formal game-theoretic model that gifts serve as "signals" of a person's intentions about future investment in a relationship, and inefficient gifts can be better signals. Other explanations for the inefficiency of gift giving are advanced, and some stylized facts about gift-giving practices are described (many of which are consistent with the signaling view of gifts)

Reciprocal fairness and gift exchange practices in the labor

We aim at investigating to what extent reciprocal considerations, exhibited by employers and employees, should lead to stable gift exchange practices in the labor contract, giving rise to non- compensating wage differentials among industries. We use the concept of Sequential Reciprocity Equilibrium developed by Dufwenberg & Kirchsteiger (1998) to incorporate players’ preferences for reciprocity in their utility function. We model the labor relation through a one shot sequential gift giving game between an employer who proposes a wage given the employee’s profitability level as exogenous and an employee who chooses his level of effort. We show that successful gift exchange practices may arise if both players are actually motivated by reciprocity. Even though intentions act as a catalyst of opportunistic behaviors, the respect of the equity norm makes mutual cooperation more likely. We propose a direct evaluation of the determinants of gift exchange practices between French employers and employees, estimating the probabilities to observe productivity increases following upon the settlement of rent-sharing agreements in the firm. Whether we estimate the probability for the employer to propose a rent-sharing agreement or the probability for the employees to raise their effort, we show that there exists an endogeneity bias related to the variable chosen as proxy to express the agents’ perception of their opponent’s fairness. This result gives support to the hypothesis that French employers and employees’ decisions are directly influenced by reciprocity concerns. Our results give support to the Akerlof & Yellen’s fair wage effort hypothesis as an explanation of the persistence of non-compensating wage differentials.employment relationship, gift exchange game, reciprocity, rent sharing

The Effect of Motivations on Social Indirect Reciprocity: an Experimental Analysis

This paper investigates the effects of motivations on the perceived kindness of an action within the context of strong social indirect reci- procity. We test experimentally the hypothesis that, for a given dis- tributional outcome, an action is perceived by a third party to be less kind if it can be strategically motivated. The results do not support this hypothesis: social indirect reciprocity is indeed found to be signif- icantly stronger when strategic motivations cannot be ruled out. We interpret these findings as an indication of the role played by team reasoning in explaining reciprocal behavior.Indirect Reciprocity, Motivations, Social Preferences, Laboratory Experiments

A cross-cultural study of reciprocity, trust and altruism in a gift exchange experiment

experimental design;altruism;social security;gift giving

Words Speak Louder Than Money

Should one use words or money to foster trust of the other party if no means of enforcing trustworthiness are available? This paper reports an experiment studying the effectiveness of two types of mechanisms for promoting trust: a costly gift and a costless message as well as their mutual interaction. We nest our findings in the standard version of the investment game. Our data provide evidence that while both stand-alone mechanisms enhance trust, and a gift performs significantly worse than a message. Moreover, when a gift is combined with sending a message, it can be counterproductive.Communication; content analysis; experimental economics; gift giving; investment game; message; trust; trustworthiness