Leveraging surrounding past strategies to maintain cooperation in the perverse prisoner's dilemma

In spatial game theory, developed models preserving cooperators often incorporate memory to enhance realism. This study examined the role of memory in a spatial prisoner's dilemma. In the proposed model, all players use their own and their neighbors’ past memories and current states to update strategies under specific conditions. When a player's score is lower than that of a neighbor using the same strategy, and that neighbor has the highest score among all neighbors, the player revisits past strategies and adopts a less experienced strategy. This rule adjusts behavior under unfavorable conditions. Results showed that the proposed model effectively retains cooperators. Previous studies have often necessitated the use of long-term memory and intricate systems; however, the present model eliminates these requirements. Instead, it sustains cooperation by employing a strategy that relies on minimal historical information when determining the subsequent course of action.