Promotion of cooperation due to reputation-based conditional interaction.

<p>Panel (a) shows the cooperation level as a function of <i>r</i> for different values of <i>h</i>. Panel (b) shows the cooperation level as a function of <i>h</i> for different values of <i>r</i>. It can be observed that cooperation can evolve even for large value of <i>r</i> in the mode of conditional interaction, and there exist intermediate tolerance ranges leading to the optimal cooperation level. Here, <i>k</i> is set to