Cooperation driven by alike interactions in presence of social viscosity.

Cooperation observed in nearly all living systems, ranging from human and animal societies down to the scale of bacteria populations, is an astounding process through which individuals act together for mutual benefits. Despite being omnipresent, the mechanism behind the emergence and existence of cooperation in populations of selfish individuals has been a puzzle and exceedingly crucial to investigate. A number of mechanisms have been put forward to explain the stability of cooperation in the last years. In this work, we explore the evolution of cooperation for alike (assortative) interactions in populations subject to social viscosity in terms of zealous individuals. We present a comprehensive study on how a finite fraction of these committed minorities present in both cooperators and defectors govern the evolutionary game dynamics where interactions among the individuals with same strategy are more probable than random interactions. We perform a detailed analysis concerning this synergy between alike interaction and the social viscosity in the opposing individuals. We scrutinize all three principal social dilemmas, namely, the prisoner's dilemma, the stag-hunt, and the snowdrift game, under such evolutionary setting. We have been successful to delineate this evolutionary scenario theoretically based upon the generalized replicator dynamics in the well-mixed regime.