The coupling effect between the environment and strategies drives the emergence of group cooperation

The coupling effect between the environment and strategies drives the emergence of group cooperation Changyan Di, Qingguo Zhou, Jun Shen, Jinqiang Wang, Rui Zhou, Tianyi Wang The coupling effect between macro environment and individual behavior is the key factor to solve the social dilemma. In a static environment, rewards of different strategies are compared simultaneously, leading to a social dilemma due to the higher payoff of defection compared to cooperation. However, when individuals are placed in a dynamic environment that is coupled with their actions, we find that the expected payoffs of different strategies are not fixed but undergo dynamic changes. The higher expected payoff of defection can be diluted over time due to environmental degradation caused by an excessive number of defectors, while cooperation may become the dominant strategy if positively reinforced by environmental feedback. Group cooperation emerges as a direct result of a mutually reinforcing positive feedback loop among the environment, immediate rewards, and individual actions (or group states). Despite the agents' lack of awareness regarding the macro-level context, they possess the ability to astutely discern the inflection point of the environment solely through their rewards. This pivotal moment prompts agents to experience a surge in immediate rewards, thereby triggering a positive feedback loop among the environment, their rewards, and their current actions. Consequently, cooperation emerges within the group.