Figure 4
Visualizations of UIs in the iterated PD with the ZD strategies in the ‘Facebook’ network.
The UIs are denoted by red circles. (a,b) show the UIs in the ‘Facebook’ network for 
and 
with 
, respectively. The size of a circle is proportional to an individual’s degree. Note that the sizes of the UIs are magnified 5 times since a large number of circles are overlapped. The simulation settings of the games are consistent with Fig. 3.
