Distribution of link update events in terms of relative generosity Δg and relative payoff Δπ.
The mean is shown as the yellow circle. (a) In the recipient-only treatment, most links are added to less successful targets. Generosity does not have a significant effect (51% added to less generous, p = 0.88). The mean is (−0.37, −0.57). (b) Links to more generous and less successful are rarely removed. Here, update events are spread throughout the other quadrants. The mean is (−2.17, 2.89). (c) In the reciprocal treatment, most links are added to less successful targets. The slightly larger fraction added to more generous is not statistically significant (52% added to less generous, p = 0.08). The mean is (−0.62, −1.93). (d) Links to more successful targets are removed more often. The effect of generosity depends on the target category: links to more generous reciprocals are removed more often, whereas links to less generous reciprocals are removed more often (shown in the inset panel). For reciprocators the mean is (5.36, 3.09), whereas for non-reciprocators the mean is (−6.14, 0.70).