Spatial prisoner's dilemma games with zealous cooperators.

Area of Science:

• Evolutionary Game Theory
• Computational Social Science
• Network Science

Background:

• Zealots, defined as individuals who always cooperate regardless of outcomes, have been theorized to increase cooperation in well-mixed populations.
• This phenomenon, termed 'social viscosity,' was thought to enhance cooperation levels in prisoner's dilemma games.

Purpose of the Study:

• To investigate the impact of zealots on cooperation dynamics when spatial structures are introduced.
• To determine if the presence of zealots remains beneficial in non-well-mixed populations.

Main Methods:

• Agent-based modeling and simulation of spatial prisoner's dilemma games.
• Analysis of evolutionary dynamics on different network topologies, focusing on homogenous lattices.

Main Results:

• The introduction of zealots can be counterproductive, leading to a decrease in overall cooperation.
• Homogenous network topologies, such as lattices, are particularly susceptible to this negative effect.
• Never-converting cooperators (zealots) were observed to destroy cooperation rather than boost it.

Conclusions:

• The beneficial effect of zealots on cooperation is contingent on the population structure.
• Spatial structures, especially homogenous ones, can invert the expected role of zealots, making them detrimental to cooperation.
• Understanding evolutionary dynamics in spatial games requires considering network topology and agent behaviors like zealotry.