It's supposed to work that way…

Against modern notions of “altruism” we found that benefits were generally intended to foster mutuality, by creating or maintaining social bonds. This expectation of reciprocity, with its (non-legal) obligations, created cyclical patterns of gift-and-return, even where there were large differentials in power between givers and recipients.—J. M. G. Barclay, Paul and the Gift, 562