Investigating the effectiveness of individuals' historical memory for the evolution of the dilemma

Individual decisions are continuously influenced by a variety of factors such as past experiences, gains, and losses. In this study, we propose an evolutionary prisoner's dilemma game model that incorporates individuals' historical memory. We analyze how the proportion of individuals with memory, memory factor, memory length, and fitness sensitivity index impact the cooperative emergence in two types of relational networks. We identify several critical factors that can facilitate cooperation among individuals. Through numerous simulation experiments, our results show that (i) A higher proportion of individuals with memory promotes cooperative behavior in a homogeneous relational network, while the opposite occurs in a heterogeneous relational network. (ii) Individuals who base their strategies solely on recent gains or are too sensitive to fitness changes are not conducive to group cooperation, regardless of the relational network structures. (iii) Individuals who base their strategies on a longer history of gain are more likely to exhibit cooperative behavior in games. (iv) The average cooperative frequency of individuals with memory is higher than that of those without memory when the fitness sensitivity index is lower. Our study provides insights into the role of individuals' memory and the impact of relational networks on cooperative emergence.