In a setting where heterogeneous agents interact to accomplish a given set of goals, cooperation is of utmost importance, especially when agents cannot achieve their individual goals by exclusive use of their own efforts [1]. Even when we consider friendly environments and benevolent agents, cooperation involves several issues: with whom to cooperate, reciprocation, how to address credit assign...

Claims of reciprocity (or reciprocal altruism) in animal societies often ignite controversy because authors disagree over definitions, naturalistic studies tend to demonstrate correlation not causation, and controlled experiments often involve artificial conditions. Food sharing among common vampire bats has been a classic textbook example of reciprocity, but this conclusion has been contested ...

In 3 experiments, Ss' public statements of attitude change conformed to the norm of reciprocity, in that the most change on a topic was accorded to a persuader who had yielded to the S's earlier persuasive attempt on a prior topic, and the least such change was accorded to a persuader who had resisted the S's persuasive attempt. This tendency was unaffected by perceptions of the persuader's lik...

In 1963-1964 W. D. Hamilton introduced the concept of inclusive fitness, the only significant elaboration of Darwinian fitness since the nineteenth century. I discuss the origin of the modern fitness concept, providing context for Hamilton's discovery of inclusive fitness in relation to the puzzle of altruism. While fitness conceptually originates with Darwin, the term itself stems from Spencer...

This paper analyzes reciprocation strategies in peer-to-peer networks from the point of view of the resulting resource allocation. Our stated aim is to achieve through decentralized interactions a weighted proportionally fair allocation. We analyze the desirable properties of such allocation, as well as an ideal proportional reciprocity algorithm to achieve it, using tools of convex optimizatio...

The ‡uctuations in incomes inherent in rural communities can be attenuated by reciprocal assistance. A model of reciprocal assistance based upon rational action and voluntary participation is presented. Individuals provide assistance only if the costs of so doing are outweighed by the bene...ts from expected future reciprocation. A distinction is made between general reciprocity where the count...

In a setting where heterogeneous agents interact to accomplish a given set of goals, cooperation is of utmost importance, especially when agents cannot achieve their individual goals by exclusive use of their own efforts [1]. Even when we consider friendly environments and benevolent agents, cooperation involves several issues: with whom to cooperate, reciprocation, how to address credit assign...

Human beings exhibit substantial interpersonal trust-even with strangers. The neuroactive hormone oxytocin facilitates social recognition in animals, and we examine if oxytocin is related to trustworthiness between humans. This paper reports the results of an experiment to test this hypothesis, where trust and trustworthiness are measured using the sequential anonymous "trust game" with monetar...

We investigated the effect of structural interdependencies between groups (especially inequality), and interdependencies between individuals on ingroup favoritism in minimal group situations. Previous research has attempted to determine whether ingroup favoritism is produced by categorization or intragroup interdependencies (reciprocation expectations), but recent literature suggests that it is...