Both helpers and recipients reported that the benefits of help outweighed the costs (i.e., the help was non-zero-sum); helpers underestimated the degree to which recipients felt indebted as a result of receiving help

Helping behavior is non-zero-sum: Helper and recipient autobiographical accounts of help. Michael R. Ent et al. Evolution and Human Behavior, February 19 2020. https://doi.org/10.1016/j.evolhumbehav.2020.02.004

Abstract: In three studies (n = 427), participants wrote and answered questions about autobiographical episodes involving helping behavior from the perspective of the helper vs. the recipient. Both helpers and recipients reported that the benefits of help outweighed the costs (i.e., the help was non-zero-sum). Helpers underestimated the degree to which recipients felt indebted as a result of receiving help. Recipients displayed a pattern of language use indicative of self-focus to a greater extent than helpers. These effects were found whether helpers and recipients reflected on the same helping episode (Study 1) or different episodes (Studies 2 and 3). People who recalled helping strangers reported that the benefits outweighed the costs to a greater extent than those who recalled helping friends or family members (Study 3), largely because the costs were greater when helping friends and family.