Evolution of cooperation has traditionally been studied by assuming that individuals adopt either of two pure strategies, to cooperate or defect. Recent work has considered continuous cooperative investments, turning full cooperation and full defection into two opposing ends of a spectrum and...

Previous research on cooperation has primarily focused on egalitarian interactions, overlooking a fundamental feature of social life: hierarchy and power asymmetry. While recent accounts posit that hierarchies can reduce within-group conflict, individuals who possess high rank or power tend to...

Social dilemmas are among the most puzzling issues in the biological and social sciences. Extensive theoretical efforts have been made in various realms such as economics, biology, mathematics, and even physics to figure out solution mechanisms to the dilemma in recent decades. Although...

Improving and maintaining cooperation are fundamental issues for any project to be time-persistent, and sanctioning free riders may be the most applied method to achieve it. However, the application of sanctions differs from one group (project or institution) to another. We propose an optional,...

In this paper, we study cooperation and coordination in a threshold public goods game with asymmetric players where players have different endowments 𝑒𝑖, productivities 𝑝𝑖, and rewards 𝑟𝑖. In general, this game has a defective Nash equilibrium (NE), in which no one contributes,...

Paying it forward" is a behavior in which people help someone else because they were helped in the past. Although experimental evidence exists that indicates that real human beings often "pay-it-forward" even in the face of free-rider risks, the theoretical basis for the evolution of this...