The impact of anxiety on cooperative behavior: A network evolutionary game theory approach

•The higher the anxiety of the player, the greater the tendency to change strategy, and we introduce an anxiety threshold θ to crystallize this tendency.•A combination of endogenous anxiety and peer pressure, both of which are sources of anxiety, is considered to be more relevant.•The collapse threshold λ is introduced to explore the factors influencing the proportion of overanxious people, making the study more realistic.•Analyzing the cross-elasticities to determine the importance of each influencing factor. Complex and intense competition always exists in human society, in which people would inevitably feel anxiety due to failure. Anxious people would doubt their own strategies and try to change them. For the individuals, anxiety stems mainly from their past failures and from their concerns about the current lack of competitiveness, which could be identified as two sources of anxiety. Based on the Prisoner's Dilemma, we synthesize these sources of anxiety and propose a new model that can reflect the impact of anxiety on people's strategies. We consider the effect of anxiety on the evolution of a group in a square lattice network with periodic boundaries, and propose the rules for quantifying the individual's anxiety and for updating the individual's strategies. Simulation results from our model show that if the players focus more on the past game records or have a strong resilience to stress, then this can lead to stable cooperation in the group. In addition, we consider the overanxious individuals in the group and explore the ways to reduce the number of overanxious individuals by analyzing them in terms of the combined effects of the peer pressure and the temptation to betray.