Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which recip...

introduction quality control (qc) techniques are used in monitoring and maintenance of the components of an x-ray system. qc of radiology devices plays a significant role in reduction of medication dose and optimization of image quality. this study aimed to conduct qc tests on randomly selected radiology devices, installed in diagnostic imaging departments of iran. materials and methods in tota...

politics as an arena of macro decisions that influence on life of all human, from the start, connected to current thought in societies, but because that such conjunction done more according to necessity, events and or selectivity, therefore led to specific results for each two. in modern age, for the sake of birth of new age and its reciprocity with subjective and objective structures in past, ...

Strong reciprocity theorists claim that punishment has evolved to promote the good of the group and to deter cheating. By contrast, weak reciprocity suggests that punishment aims to restore justice (i.e., reciprocity) between the criminal and his victim. Experimental evidences as well as field observations suggest that humans punish criminals to restore fairness rather than to support group coo...

Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainabl...

We produce a new proof of the reciprocity law for the twisted second moment of Dirichlet L-functions that was recently proved by Conrey. Our method is to analyze certain two-variable sums where the variables satisfy a linear congruence. We show that these sums satisfy an elegant reciprocity formula. In the case that the modulus is prime, these sums are closely related to the twisted second mome...

This paper develops a triadic design for conducting trust and reciprocity experiments. A large literature on single-game trust and reciprocity experiments is based on the assumption that subjects’ utility payoffs are the same as their own monetary payoffs in the experiments. Such designs test compound hypotheses that include the hypothesis that other-regarding preferences do not affect behavior...