This paper states why we sometimes make seemingly illogical and irrational altruistic behaviours in a chain of cooperation. Roughly speaking, such a type of behaviour is named as upstream indirect reciprocity in academia and called as “pay it forward” in Hollywood (You’ve already forgotten a little-bit innocent and naïve film in 2000 that was praised mainly for performances of Kevin Spacey, Helen Hunt, and Haley Joel Osment?)
In contrast with another type of indirect reciprocity (so-called downstream indirect reciprocity), which is thought to be performed for improvement of one’s own reputation, it has been poorly understood why the pay-it-forward reciprocity can be seen universally in human society.
The present findings based on functional MRI and grey matter volume analysis (VBM) suggest that this apparently irrational cooperative behaviours are established by regarding affective empathy as a kind of reward. These observations are expected to help us to understand one of the most humanistic but sometimes least achievable behaviours. Ultimately, it might lead us to construct social systems that enhance inter-individual cooperations, although I don’t know whether such a society is good one or just weird one.
I will upload more academic and modest presentation later, but if you kindly want to know more details, you can read the article on PNAS site because it is open access.
Watanabe T, Takezawa M, Nakawake Y, Kunimatsu A, Yamasue H, Nakamura M, Miyashita Y, Masuda N.
Two distinct neural mechanisms underlying indirect reciprocity
2014 PNAS
