The effect of individual attitude on cooperation in social dilemma

Abstract

Environmentalists spend something such as, time, energy and money to protect the environment, while others in the same environment pay nothing. In this social dilemma associated with the ecological environment, we consider environmental investment and draw some interesting and meaningful conclusions by abstracting a differential equation model, based on the mean field approximation to discuss the impact of various environmental budgets on the dynamics in estimable social states. Firstly, we consider each individual having dual attributes of attitude and behavior, and classify the well-mixed and infinite populations into four categories, namely, indifferent cooperator, passionate cooperator, indifferent defector and passionate defector. The system may be in one of four situations — only the indifferent defectors are left, two types of defectors are survived, two types of cooperators are remained and four types of individuals coexist. A serious of numerical results show that one of causes for environmental tragedy is the indifferent of the public. Increasing investment in environmental protection projects can result in more cooperators if the society is not too hardhearted. When the investment exceeds a threshold, however, more investment has no obvious effect on promoting cooperation further. We should draw public attention to environmental problems and make a reasonable budget for environmental protection so as to promote green and harmonious development to the greatest extent.