Moderate irrational sentiment-driven fitness can promote cooperation in the prisoner’s dilemma game

Abstract

In this work, we investigate the impact of irrational sentiment on spatiotemporal dynamics of cooperation in prisoner’s dilemma (PD) game. Generally, players update strategies by comparing the payoffs with that of their neighbors, however, in real life, people often produce some irrational sentiment due to the payoffs and misjudgment of their situation. For example, some players tend to perform so confident that they overestimate their capabilities. In contrast, others are self-esteem and underestimate themselves. So we integrate a player’s irrational sentiment into his fitness calculation via a parameter θ. Then we separate the players into two types: type A (ordinary players) and type B (irrational players: individuals making decision are affected by irrational sentiment). Numerous simulations show that players moderately overestimating and underestimating reality can enhance cooperation. In addition, the more the players with moderate irrational sentiment, the more evident of promoting cooperation. Besides, overestimation (θ>0) can enhance cooperation in a larger range of θ value. And underestimation (θ<0) can enhance cooperation to a higher degree rapidly. Our analytical results provide a novel perspective to explore the influence of people’s sentiment on evolutionary cooperation.