Role of Different <i>β</i> in Evolution of Cooperation

<p>Fraction of cooperators as a function of <i>T</i> for different values of <i>β_e</i> and <i>β_a</i>. We maintained <i>z =</i> 30 and <i>N =</i> 10³. The dilemma corresponds to the diagonal in the PD domain from {<i>S =</i> 0;<i>T =</i> 1} to {<i>S= −</i>1;<i>T =</i> 2} corresponding to a classical PD in which <i>+ ∞ > b/c ≥ 2</i>. The insets provide the maximum degree of the network for the different values of <i>T</i> and <i>S</i>. Both <i>β_e</i> and <i>β_a</i> contribute similarly (but not independently) to the evolution of cooperation. The smaller the values of <i>β_e</i> and/or <i>β_a,</i> the more the less fit will have a chance of survival; hence, the easier it is for cooperation to thrive.